At this point, the article analyzes the effect of losing speed in the series of repetitions within strength training.

In this series of articles we deal with some of the most important concepts of strength training, collecting notes from the recently published book Strength, Speed ​​and Physical and Sports Performance written by renowned researchers Juan José González Badillo and Juan Ribas Serna.

SUMMARY

• The loss of speed in the series can serve as a predictor of the degree of metabolic stress caused by training, and therefore it is a good indicator to estimate fatigue.
• Doing half or less of the repetitions achievable in the series produces notable improvements in muscular strength and sports performance.
• People who train for improved health should not do even half of the possible repetitions in the series.
• Most experienced athletes with medium-high strength needs will probably be able to perform at most half or 1-2 repetitions more than half of the possible ones.
• A subject should not lose more than 20-35% (depending on each exercise) of the speed of the first repetition in the series.

This is the second question related to the definition of the stress character (CE) as a solution to the problems raised by RM and XRM. Speed ​​control not only makes it possible to know very precisely the true effort that a given load (mass) represents when doing the first repetition of a series, but also allows complete knowledge of the degree of effort made by knowing in what proportion or percentage speed is lost as repetitions are made within the series.

And this is important because the loss of speed is a highly valid indicator to estimate fatigue (Edman, 1992; Allen, Lamb, 8 Westerblad, 2008). This validity is based on the high relationship that exists between the loss of speed in the series and the loss of speed at a certain absolute load measured before and immediately after making the effort.

speed loss is a highly valid indicator to estimate fatigue

In turn, the loss of speed in the series can serve as a predictor of the degree of metabolic stress caused by training. Indeed, Sánchez-Medina and Gonzalez-Badillo (2011) carried out a study with 15 types of effort in the bench press and squat, with loads that could be done between 12 and 4 repetitions per series. These intensities correspond to mean relative intensities between 70 and 90% of the RM, although each subject did not really make the effort exactly with said intensities, but with the absolute loads with which they could do the marked repetitions.

The absolute loads used were those with which 12, 10, 8, 6 and 4 maximum repetitions could be done, which, on average, corresponds to relative intensities of 70, 75, 80, 85 and 90% of the RM. , respectively. The greatest effort with each load consisted of doing three series with the maximum number of repetitions possible (or one less than possible in the first series) and the least effort in doing three series with half the possible repetitions.

In addition, one or two more efforts were made with an intermediate number of repetitions. For example, with the load that 12 repetitions could be done, four efforts were made, performing three series of 12, 10, 8 and 6 repetitions in the series, which were represented as follows: 3×12(12), 3×10(12) , 3×8(12) and 3×6(12).

In total, 15 efforts were made with each of the exercises: bench press and squat. The valuation of The degree of fatigue generated with each effort was determined through the loss of speed with the load that could be moved at 1 m*s-1 before making the effort., as well as the loss of jump (really loss of execution speed) pre-post effort when the squat exercise was performed.

Before starting the squat training, the vertical jump test (CMJ) was performed after a specific warm-up. In both exercises, the warm-up began with progressive loads and when passing through the load that could be moved at approximately 1m*s-1, three repetitions were performed with it and the value of the load and the concrete average speed of the three repetitions were noted immediately after making the effort, the measurement was made again. jump (after the squat) and the load of 1 m*s-1 in both exercises.

Since the minimum load with which the efforts were made was approximately 70% of the RM, an approximate load of 60% was always used in the squat during the warm-up (load that moves approximately 1 m*s-1). and 45% in bench press (load that moves approximately 1 m*s-1).

In addition, after each effort, lactate and ammonium levels were measured. In figure 1 you can see the scheme of the execution of the efforts and the initial and final tests, in this case in the bench press exercise and with the load that could be done 12 repetitions: 3 series of 12 repetitions being able to make 12: 3×12(12).

In this case, the average speed before the effort with the load of 1 m*s-1 was 1.03 m*s-1. The subject continues his warm-up until he reaches the load with which he has to carry out the effort of the day: 3×12(12) and performs the 3 series at the maximum possible speed, with 5 minutes of recovery between series.

The speed with each repetition in the three series is represented by the three groups of central bars with a tendency to decrease. Immediately after (10-15 s) the last repetition of the last series, the load with which the speed of 1 m*s-1 was initially reached was measured again. In this case, the final average speed of the three repetitions was 0.71 m*s-1. The loss of speed, in this case 31.1%, reflects the quantification of fatigue.

The loss of speed, in this case 31.1%, reflects the quantification of fatigue.

Figure 1. Outline of the protocol followed in an effort of 12 repetitions, being able to do 12: 3×12(12), in the bench press exercise. Red bars, speed with the load of 1 m*s-1 before and after making the effort. Rest of the bars: speed with each repetition in the three series performed with the expected load (Sánchez-Medina and González-Badillo. Med. Sci. Sports 2011)

As a result of this study, high relationships were found between the loss of speed in the series and the loss of speed with the load that moved 1 m*s-1 before the effort, both in the bench press (r = 0, 97) as in the squat (r = 0.91), and with the loss of height (loss of speed) in the jump after the squat (r = 0.92). These results confirm that the greater the speed loss in the series, the greater the fatigue.

Later on, it will be analyzed more precisely how the degree of fatigue (loss of speed with the load of 1 m*s-1 and loss of jump) is dependent on the speed of the first repetition (real percentage of the RM) and of the series loss. Likewise, high curvilinear relationships were found between the speed loss in the series, the jump loss and ammonium [R2 = 0.89 in the bench press; R2 = 0.85 in the squat and R2 = 0.86 in the CMJ (figure 2).

Figure 2. Relationship between velocity loss and ammonium concentration with bench press (top figure) and squat (middle figure) exercises, and relationship between vertical jump losses after squat exercise and ammonium concentration (bottom figure). ). Note that from an approximate loss of speed in the series of 40% in the bench press, 30% in the squat, and 12% in the vertical jump, the ammonium concentration shoots up. (Sánchez-Media y González-Badillo, 2011)

An important and unique observation to date is that for an increase in ammonia to occur it was necessary to perform 1-2 repetitions more than half the number possible at any load and in both exercises. This can be seen in figure 3. The horizontal dotted line represents the baseline ammonium value. Only when more than half of the possible repetitions in the set are performed does the ammonium spike with an exponential trend.

For an increase in ammonium to occur, it was necessary to perform 1-2 repetitions, more than half of those possible, at any load.

This occurs in both the bench press and the squat, with very similar behaviors. Figure 2 also shows this trend.

Figure 3. Evolution of ammonium concentration in relation to the number of repetitions performed in the series with the bench press (left) and right full squat exercises. It is observed that for the ammonium to exceed the resting values, marked by the dotted line, it is necessary to do 1-2 repetitions, more than half of those possible in the series (Sánchez Medina and González Badillo, 2011). Figure taken from Sánchez-Medina’s Doctoral Thesis.

This behavior of ammonium could be at the base of the explanation of the proposals or hypotheses (based on experience and systematic observation, not on experimental data, when speaking of training to failure).) made in the 80s, with studies of the effect of non-maximal volumes (65 and 85% of the maximum achievable), or of training with half or less of the possible repetitions in the series of the National Field Hockey team of the 90s, or the first experimental studies that were designed in which one group did half the repetitions possible in the series and the other all the possible ones.

the appearance of ammonium above the basal values when lifting weights may mean that the effort is at the limit that should be reached.

And this is so because the appearance of ammonium above the basal values when lifting weights (in other types of exercises it may be different, and it certainly is) may mean that the effort is at the limit that should be reached.

The measurement of the loss of speed in each repetition and the degree of fatigue generated -measured through the loss of speed with the load of 1 m*s-1 and loss of jump- allow us to add much more precise information about this behavior. of ammonium than the simple count of the repetitions performed.

These speed losses in the series from which the ammonium is fired correspond to certain speed losses with the 1 m*s-1 load and height loss in the jump. The data with the following:

• With a loss of 40% speed in the bench press, ammonium is triggered (figure 2) and would correspond to a loss of speed of 17% with a load of 1 m*s-1.
• With a 30% loss of speed in the squat, ammonium is triggered and would correspond to a loss of speed of 12.5% with the load of 1 m*s-1.

With a 12% loss in jump height, ammonium shoots up and would correspond to a loss of speed in the series of 32% (Sánchez-Medina and González-Badillo, 2011).

It can be observed how the same fatigue generated when performing the squat, with 30 and 32% loss of speed in the series, is estimated in an equivalent way by the loss of speed with the load of 1 m*s-1 (12.5 %) and height in the jump (12%), respectively. This indicates that the loss of speed is an accurate indicator of fatigue, since its quantification before the same effort (loss of 30-32% of speed in the squat) can be done at different speeds, giving practically identical results.

In this case, the initial speed of 1 m*s-1 in the squat and the speed of the vertical saint have been used, which, on average, is performed at a clearly higher average speed, which could be approximately more than 1.5 m-s. * on average, which would be equivalent to a little more than 45 cm of initial jump.

If now the two variables used are analyzed: the loss of speed in the series and the number of repetitions performed, it can be confirmed that in the bench press exercise the loss of speed when half of the possible repetitions has been done is between 25 and 30% (González-Badillo et al., 2017) of the speed of the first repetition, that is, slightly below the loss caused by the ammonium shot, and that in the complete squat the loss of speed when doing half of the possible repetitions it would be approximately 15-20% (Rodríguez-Rosell et al., 2019), that is, also below the loss of speed caused by the increase in ammonia.

Therefore, if it is known what degree of effort (degree of fatigue) means each percentage of speed loss in the series, the application of speed as a training control method is very useful, it is probably the best procedure to estimate with high precision and immediately the training load.

ammonium concentration above quiescent values can be controlled by the loss of speed in the series

This load would be determined by the degree of fatigue caused by the joint effect of the volume and intensity used in training. Therefore, the ammonium concentration above the resting values can be controlled by the loss of speed in the series, since there is a close relationship between the loss of speed in the series and the percentage of repetitions performed (González-Badilo et al, 2017; Rodriguez-Rosell et al., 2019).

If, furthermore, it is known, through extensive practical experience, that doing half or less of the repetitions achievable in the series produces notable improvements in muscular strength and sports performance, it would not be very advisable to frequently exceed (in some cases it would never be necessary) half of the repetitions that can be done in a series. This practical experience has been reinforced by experimental studies in which it has been proven that losing 10-20% of the speed in the series, which is equivalent to performing half or less of the possible repetitions in the series, in the exercise of squat offers better results than losing 30-40%, which leads to a situation at the limit of ammonium increase (30% loss) or very close to muscle failure (40%) (Pareja-Blanco et al., 2017 ; Rodríguez-Rosell, Doctoral Thesis).

In addition to the relationship with ammonium, velocity loss also showed high positive linear correlations with lactate concentration: [r = 0.95 in the bench press, r = 0.97 in the squat, and r = 0.97 in the the jump (figure 4)].

Figure 4. Relationship between velocity loss and lactate concentration with bench press (upper figure) and squat (middle figure) exercises, and relationship between vertical jump losses after squat exercise and lactate concentration (lower figure). ). (Sánchez-Medina and González-Badillo, 2011).

Doing half or less of the repetitions achievable in the series produces notable improvements in muscular strength and sports performance.

If the regression equations corresponding to each of the relationships of the three exercises with lactate are applied, it is verified that before a 40% loss of speed in the bench press series, which is when ammonium is triggered, the lactate would be 5.3 mmol/L, in the squat, when ammonium increases, when losing 30% of the speed, lactate would be 7.2 mmol/L, and in the jump, when 12% is lost jump and the ammonium increase begins, the lactate would be 7.7 mmol/L.

As can be seen, the height loss in the vertical jump (12% jump loss and 32% speed loss in the squat) when ammonium is fired it corresponds to practically the same concentration of lactate than when ammonium is triggered by the loss of speed in the series in the squat exercise (30%).

Which corresponds to the behavior observed when analyzing ammonium. Therefore, ammonium begins to rise when lactate is 5.3 mmol/L in the bench press and 7.2 mmol/L in the squat (figure 15.14). From this relationship it can be deduced that, although it is not the most practical and viable option, if one wanted to analyze the possible behavior of ammonium without measuring it, given its greater difficulty and price, one could measure lactate to predict at what moment the lactate begins to be triggered. ammonium.

Although, naturally, the most precise, economical, easy-to-perform procedure and with immediate information is the control of speed loss in the series.

Figure 5. Relationship between lactate values and ammonium firing in bench press and squat exercises (Sánchez-Medina and González-Badillo, 2011)

There were also high relationships between stalling and testosterone (r=0.83), growth hormone (r= 0.82), and insulin (r= 0.88). These relationships increased for ammonium (p = 0.94-96) and lactate (p = 0.98) when Spearman’s rank correlation coefficient was used (data from the same unpublished study). All these relationships indicate that the higher the speed in the series, the greater the mechanical, metabolic and hormonal stress tends to be, the greater the degree of effort generated.

the greater the speed loss in the series, the greater the mechanical, metabolic and hormonal stress tends to be, the greater the degree of effort generated.

The question that should be asked as a result of this knowledge is what should be the optimal loss of speed in each case. This question, of course, does not have an easy answer, but being able to ask it, and having the appropriate mechanical and physiological data available to try to find an answer, is already a great advance.

In the next articles, useful studies for the practice of training and that provide answers to many of these questions will be reviewed.

Conclusions

From the above it can be deduced that the knowledge of the relationship between the loss of velocity in the serle and the loss of velocity with the load of 1 m*s-1 and the height of the CMJ, as well as the metabolic stress allows us to conclude the following:

• The fatigue caused by a training session of three sets with loads that allow you to do between 12 and 4 repetitions per set depends on the percentage of speed lost in the set.
• The training load can be quantified by the loss of jumping capacity and the loss of speed before a determined load (mass) in each session.
• The relationship between the loss of jump and the loss of speed could be verified before a determined load per session and the effect of the training.
• The loss of velocity in the series with the load of 1 m*s-1 and in the CMJ are accurate estimators of the metabolic stress caused by the training session.
• Depending on the metabolic stress generated, a subject should not lose more than 20-35% (depending on exercises) of the speed of the first repetition in the series:
  • Performance is probably not better if you lose a higher percentage of speed. In the squat exercise, an average loss of speed in the set of 10-20% offered better results than a loss of 30-40%.
  • In the bench press exercise, a mean loss of 27.7% outperformed losing 53.3% (unpublished laboratory data).

a subject should not lose more than 20-35% (depending on exercises) of the speed of the first repetition in the series

• If you do a training session of three sets with any load between those with which you can perform between 12 and 4 repetitions per set, performing a range of repetitions between half and the maximum of the possible repetitions in the series, ammonium increases exponentially from a loss of speed of 40% in the bench press and 30% in the squat. In the case of the vertical jump, the increase in ammonia occurs when a pre-post effort jump loss of 12% is reached.
• As a practical application of synthesis, it is suggested:
  • People who train for improved health should not do even half of the possible repetitions in the series.
  • Most experienced athletes with medium-high strength needs will probably be able to perform at most half or 1-2 repetitions more than half of the possible ones. Although we also estimate that athletes with lower strength needs probably, even if they are very experienced, do not need to perform even half of the possible repetitions in the series at any time.

In previous articles it has been seen that there are a series of determining factors of the force that a muscle or group of muscles can generate. Afterwards, the influence of muscle activation as the cause of a series of effects that translates into certain structural and neural transformations has also been analyzed, which give rise to the fact that this muscle activation constitutes what is understood as training.

In this series of articles we deal with some of the most important concepts of strength training, collecting notes from the recently published book Strength, Speed and Physical and Sports Performance written by renowned researchers Juan José González Badillo and Juan Ribas Serna.

Well, whatever the way in which muscle activation is carried out, whether it is correctly or not, training depends on a series of factors, whether or not the training programmer is aware of them, or Whether you take them into account or not, they are the determinants of the effect produced by the training.

These factors of sports training are three.

1/3 Factors of sports training: the speed of the first repetition.

First indicator of the character of the effort (CE) and the effort index (IE). Determinant of relative training intensity

Justification.

• Because it determines the percentage of the current RM with which the subject trains: real effort that represents the first repetition
• Because given the same speed, this percentage is practically the same for all people
• Because it starts from the assumption that even if the RM value changes, the speed with each percentage is very stable. Which is sufficiently proven.

That is, even if a training programmer does not know or does not want to know that when he performs the first repetition of a set, the speed at which he executes it determines what relative intensity he is training, that speed will determine the effect of the training, because it represents a highly relevant variable of training and its effect.

If the programmer ignores this reality and programs a percentage based on a 1RM value obtained at some point, it is already known that there is a high probability that the athlete or trained person is not training with the intensity (percentage in this case) that the programmer thinks.

But without a doubt, even in this case, what will determine the effect of the training will continue to be the speed at which the load has been moved in the first repetition, which, in this case, would represent a percentage unknown to the programmer (cases are discarded). in which the programmers indicate that the loads do not move at the maximum possible speed).

The same situation would occur if the programmer proposes that you train with a load with which you can do a certain maximum number of repetitions in the series (XRM or nRM).

Everything said in the previous paragraph is valid, but with the added peculiarity that in this case the subjects, with a high probability, would train with different relative intensities. In this case, the speed control would “come to the rescue” and could determine with what actual relative intensity they trained, even though the programmer thinks it was the same for everyone.

2/3 Factors of sports training: The loss of speed in the series with respect to the first repetition

Second indicator of the character of the effort (CE) and the effort index (IE).

Justification: Because it indicates the degree of fatigue for the same speed of the first repetition and equalizes the effort for all trained subjects. That is, because although the number of repetitions performed in the series is individual (and different) for each speed of the first repetition of a series, the percentage of repetitions performed before the same loss of speed in the series is approximately the same, and for this reason, as has been verified, there will be a very similar degree of fatigue.

With the two sports training factors described, the effort made by the subject has been defined, since its product gives rise to the IE. Index that presents a high validity as an indicator of the fatigue generated by the training.

Unfortunately, if the programmer does not know the importance of the loss of speed in the series, the effect of the training will be produced with different efforts for each subject, unknown to the programmer. If the maximum number of repetitions in the series is programmed for all the subjects, the subjects will train with different intensities in most cases, but the influence of the loss of speed in the series will be present as a “factor” of the training effect. and it will be responsible, to a large extent, together with the speed of the first repetition, of the training effect.

Naturally, the programmer will not have information about what load could have produced the effects of his training, but whatever they are and whatever the reference for programming the repetitions in the series, the effect will depend on the loss of speed in the series, and , more properly, of IE.

3/3 Sports training factors: Exercise in question.

Justification:

Each exercise has a different speed for each percentage loss of speed in the series (González-Badillo, 2000). This is because the speed with each percentage depends on the speed with which the RM is reached, which is different for each exercise (González-Badillo, 2000).

This own speed determines the characteristics of the exercise in relation to the loads and frequencies that can be used. It is reasonable to think that doing a full squat exercise does not produce the same degree of fatigue as an arm push exercise. In addition, the speed of the RM means that some exercises can be trained with higher relative intensities than others.

A clear example is the comparison of the squat and the power clean. Certain athletes would not need, and should not, do a full squat with loads greater than 80% of the RM even at the end of their sporting life, even with extensive experience in strength training.

However, these same athletes can train with intensities of 75-80% of the RM in a clean force almost from the first day of training, once they have learned a fairly acceptable technique, and later they could reach intensities of 85 and even 90% of the RM in the exercise, if the technique was good.

Also, a clean workout can be done any time close to competition, and is highly unlikely to interfere with specific performance: it could be done up to a few minutes before some competitions.

These different possibilities of the exercises are related to the speed of the respective RM. A high speed of the RM acts as a “safety” of positive effect with minimal interference with any specific exercise.

In this case, the problem would come from not knowing that the speed of the RM is determinant of the characteristics of the exercises. This lack of knowledge can lead to the training being programmed with the same intensities, and even with the same repetitions per series, with exercises with very different speeds typical of RM, which can lead to proposing excessive intensities in some exercises or useless intensities. in others.

Fatigue in different types of efforts can be characterized and measured in different ways depending on the duration and intensity of the efforts. In this entry we analyze the various factors that cause fatigue according to the duration of the effort.

In this series of articles we deal with some of the most important concepts of strength training, collecting notes from the recently published book Strength, Speed ​​and Physical and Sports Performance written by renowned researchers Juan José González Badillo and Juan Ribas Serna.

SUMMARY

• In short efforts the performance is highly dependent on the oxygen consumption capacity of the subject (VO 2max)
• In efforts of up to 30 minutes, the lactate threshold point (anaerobic) is decisive.
• In efforts that last more than an hour, fatigue is highly associated with the depletion of muscle glycogen stores.
• A good metabolic indicator of stress caused by exertion is the blood lactate concentration.
• The loss of execution speed is a faithful reflection of the fatigue state of the subject.

short duration efforts

From efforts as short as 100 meters of sprint (10-12 s) there are already losses of speed (decrease in performance) involuntarily, which is an indicator that during the test there is a phase in which it manifests itself. fatigue as a loss of capacity to produce force in the unit of time.

The causes of fatigue in this type of effort are multiple, but of all of them the decrease in availability is probably the most important. Considerable increases in the plasmatic concentration of hypoxanthine, ammonia and uric acid have been observed in this type of effort. These results indicate that there have been difficulties in synthesizing ATP via ADP + CP and that energy production has been resorted to through the ADP + ADP = ATP + AMP reaction. This indicates that you there has been significant metabolic stress in the muscle cell, which can be associated with injury to said cell, and the loss of purines that can negatively influence the phosphagen reserves of the muscle, which has repercussions in the reduction of the muscle’s capacity to produce energy quickly in the following days.

Metabolic stress on the muscle cell influences the muscle’s ability to produce energy on successive days.

It does not appear that acidosis is a determining factor in these cases. In addition to what has been indicated, this fatigue is associated with a decrease in the activation of motor units in the excitation-activation process and an increase in Pi and ADP. In other short efforts such as throws, jumps, Olympic lifts and the like, fatigue is related to the same mechanisms, but with less influence from metabolic factors. If the efforts are somewhat longer (15-40 s), the participation of the phosphagen pathway to provide energy is coupled in a very important and decisive way with the ability to rapidly provide energy through the anaerobic glycolytic pathway. For this reason, in this type of effort, all the factors responsible for fatigue in the previous type of effort are present and increased, plus those derived from a drop in pH.

Therefore, it is likely that the concentration of metabolites, the alteration of calcium transport (excessive accumulation of myoplasmic calcium), the accumulation of Pi and the excess of extracellular potassium are also present as responsible for fatigue in this type of effort. The same causes of fatigue occur in efforts that last about a minute, but the fundamental difference is in a greater influence of the pH reduction, which practically reaches its maximum in efforts of this duration. High acidity, in addition to the previously described effects on the cross-bridge cycle, acts on cionide channels (which mainly govern membrane excitability), depolarizing the membrane and leading to the inactivation of sodium channels, essential for the generation of action potentials, at the end of the effort.

In this situation, the hydrogen ions themselves act by priming the working speed of the mitochondria, shifting the burden of maintaining the energy supply to the mitochondrial aerobic pathway. Given the low rate of ATP generation from the mitochondria compared to the anaerobic glycolytic pathway, the rate is clearly reduced at the end of the effort. These same causes could be applied to efforts that last up to three minutes, with a greater dependence on the ability to provide energy aerobically.

long-lasting efforts

When the efforts last between 5 and 10 minutes, performance is highly dependent on the subject’s oxygen consumption capacity (VO 2max), but there is also significant phosphagen depletion and high acidity. Therefore, in this type of effort, fatigue may depend in part on the processes related to phosphagen depletion, and to a large extent on the ability to produce energy aerobically (power and maximum aerobic capacity), but also on the power and anaerobic capacity and problems related to the reduction of pH.

In efforts of up to 30 minutes, the lactate threshold point (anaerobic) is decisive.

In efforts that last up to approximately 30 minutes, the aerobic power of the subject is still very important, but the speed at the lactate threshold point (called anaerobic) seems to be more decisive. Therefore, fatigue may be closely related to the ability to capture, transport, and use oxygen for the oxidation of glucose by the aerobic route, but especially to speed or power in conditions of suprathreshold lactatemia. In the final sprint of some tests, the depletion of muscle CP reserves or excessive muscle acidity may influence. Another factor that may be related to fatigue is high body temperature, although this would be more relevant after one hour of effort.

In efforts that last more than an hour, fatigue is highly associated with the depletion of muscle glycogen stores., and, therefore, although all the factors indicated for the previous efforts are present to some extent, the availability of glycogen stores could be a factor causing the fatigue of this exercise. In addition, glycogen depletion is associated with fatigue as it may cause decreased calcium release from the sarcoplasmic reticulum and consequent effect on muscle activation, although the link to low glycogen is uncertain. with failure of calcium release (Allen et al., 2008).

In efforts that last more than an hour, fatigue is related to the depletion of glycogen stores.

Other factors such as an excess of ammonium, an increase in muscle Mg concentration, an excessive increase in body temperature or an insufficient capacity to use lipids to produce energy could also be the cause of fatigue in this type of effort.

Efforts to overcome external loads

As we have indicated when discussing the concept of fatigue, in addition to a decrease in force production, another aspect of muscle performance such as speed of shortening is also an indicator of fatigue (Allen et al., 2008; Edman, 1992). If we take into account that the loss of speed before the same load is a direct consequence of the reduction of the force applied to said load, we must admit that the loss of speed is a faithful reflection of the state of fatigue of the subject.

It is evident that when a subject is visually perceived to be “tired” (fatigued), we detect it by the loss of execution speed, whatever the activity the subject performs: displacing an external load or displacing his own body. Speed ​​also has an advantage over force as an indicator and quantifier of fatigue, and that is that it can be measured more easily and accurately than force, and also in competition and training gestures or actions.

The loss of speed in efforts to overcome external loads is a faithful reflection of the state of fatigue.

Therefore, when a gesture has to be performed at the maximum speed possible, knowledge of the loss of speed may be the best procedure to determine the degree of fatigue in which the subject is found during and after the effort. These reasonings lead us to propose that when training is carried out through the displacement of external loads, the loss of speed in the series is an accurate indicator of the fatigue (and the load) that carrying out the exercise supposes for the subject.

Given this premise, the validation of the loss of speed in the series as an indicator of fatigue is achieved if there is a high relationship between this loss of speed during and at the end of the effort, and the reduction in contractile capacity, which could be quantified. also through the loss of speed with respect to the speed reached when displacing the same load prior to the fatiguing effort. Specifically, as mechanical indicators we can use two exercises:

1) the loss of speed before the same load, which in our case is the maximum load that can be moved approximately 1 m*s-1, and

2) the loss of jump height (which is really also a loss of speed) after the effort.

To this main validation, the relationship with indicators of the degree of stress caused by the effort could be added, which could contribute to a better knowledge of the type of effort made and the possibility of replacing the measure of certain metabolites by the loss of speed (concurrent validity ). As metabolic indicators we consider the changes in the concentration of lactate and ammonium. Indeed, a good metabolic indicator of stress caused by exertion is the concentration of lactate in the blood.

Lactate production is related to the difference between the motor command of the central nervous system and the actual mechanical execution of the muscle. The greater the difference between what is commanded by the central nervous system and what is executed by the muscle, the greater the lactate production will be. In addition, lactate production, far from being detrimental to the functioning of muscle fibers, is actually an essential component to improve muscle fiber excitability by blocking chloride channels (Ribas, 2010; González-Badillo and Ribas, 2002). As shown later, the relationship between the lactate concentration and the loss of speed of movements executed at maximum speed is excellent, such that the greater the loss of speed, the greater the production of lactate by the muscle fibers (Sánchez -Medina and González-Badillo, 2011; Rodríguez-Rosell et al., 2018).

Especially when talking about time under tension (TBT), the speed of execution in voluntary strength training can have a differentiating effect within the ways of performing the training. The usual proposal to perform the movement slowly “to increase TBT and further improve strength” does not seem to fit the reality.

In this series of articles we deal with some of the most important concepts of strength training, collecting notes from the recently published book Strength, Speed ​​and Physical and Sports Performance written by renowned researchers Juan José González Badillo and Juan Ribas Serna.

SUMMARY

• Training at very low speeds does not seem to be the most positive for improving strength and hypertrophy.
• The higher the speed, the lower the peak force can be reached, but the higher stimulus frequency is necessary to achieve it.
• The execution of the movements at the maximum speed possible allows a greater recruitment of fast fibers, the improvement of the stimulus frequency and the possibility of reaching a greater slope in the force-time curve.

The way to address the problem of the effectiveness of moving loads at the maximum possible speed or more slowly has not always been the most appropriate, which has given rise to contradictory results.

On some occasions, relative loads of different magnitude are compared, which, if they were always moved at the maximum speed possible, the absolute speeds would necessarily be different, so that what is really compared is not the speed of execution, but, in the best case, the relative intensity.

what is really compared is not the speed of execution, but, in the best of cases, the relative intensity

In most cases, training is performed until exhaustion (muscular failure), which necessarily leads to a large proportion of the repetitions being “performed at very low speed, so the average speed of the group that performs the repetitions at the maximum possible speed is very close to that corresponding to the group that performs the repetitions at the slowest speed, and even both groups will perform many of the repetitions at the same speed, since the last repetition is necessarily done at the speed typical of the RM of the corresponding exercise (Sánchez-Medina and and González-Badillo, 2011; González-Badillo et al., 2017) and the last 2-3 repetitions prior to failure would also be done at a very low speed and similar for both groups .

The final result is that there would hardly be any differences between the two groups, so there is not a sufficient maximization of the variance and the results would tend to be practically the same.

Another important problem is that when attempting to compare execution speeds, in many cases neither of the two groups performs the movement at the maximum speed possible, which means that the conditions to verify the true effect of speed do not exist, because at speeds Intermediate conditions do not exist for the “maximum speed” possible execution (force production in unit time, recruitment of fast fibers, lowering of the activation threshold…) What is usually done is to mark some times of execution, not the minimum possible, for the eccentric and concentric phases.

In line with the above, new problems are added to the aforementioned problems. Only if the loads are light or medium and few repetitions are made in the series, it is possible to maintain a certain movement speed constant, as long as this is not the maximum possible.

When trying to compare the execution speeds, in many cases neither of the two groups performs the movement at the maximum possible speed

But if you get to the muscle failure, as usual, it is not possible to maintain the same intermediate speed during all the repetitions, because as just indicated, you will always finish at the lowest possible speed in the exercise in question, regardless of what the speed was. initial velocity. As a consequence, neither the maximum speed is compared with other lower speed values ​​nor are certain intermediate speed values ​​maintained, always very close to the mean speeds of the different groups.

To give an example, one can analyze the study by Munn et al. (2005), published in MSSE and widely cited in issues related to the effect of execution speed. Four groups were formed, two “fast” and two “slow”, which performed elbow flexion with a load of 6-8RM. The two “fast” groups did 1 or 3 series at a pace of 1 s in the eccentric phase and another in the concentric phase, and the two “slow” groups also did 1 or 3 series at 3 s each phase. Recovery between sets was 2 minutes.

It is said in the study that the goal was to complete sets of 6-8RM with a load equivalent to 80% of 1RM. The first problem that we face is to know how to determine in each session the load that allows us to do the same repetitions with the same percentage with such different speeds of execution. Secondly, it is impossible to maintain the planned speeds if muscular failure is reached, because for this, all the groups would have to do their repetitions at the speed of the RM of the elbow flexion exercise, something that, obviously, is not possible. has done (nor would it make sense to do so, because it would mean overriding the layout).

In addition to the above, in no case has the movement been made at the maximum speed possible, which practically makes any design that tries to assess the effect of execution speed lose all validity, since this level —maximum speed— of the The independent variable “speed” must always be present if you want to investigate the effect of execution speed.

This is so because the effect of any velocity value would always have to be compared with the effect of the “maximum possible velocity” value. This would make it possible to check if any non-maximum speed value is greater than the maximum speed or not, and if, hypothetically, there was or was not a curvilinear, or linear, relationship between execution speed and performance.

But comparing non-maximal speed values ​​to each other without including “maximum speed” is meaningless, except that for some, “you should never train at the maximum speed possible”, which seems quite far from the truth. If the results of this study are analyzed, it is indicated that a series at high speed (1 s in each phase) is superior to doing a series at low speed (3 s in each phase) but that doing three series at 1 s compared to 3 s does not present significant differences between them.

In addition, it is indicated that doing 3 series has a greater effect than 1 series at both speeds. It is recommended that “if a series is done, it should be done at high speed (it would only be valid for a time of 1 s in elbow flexion) and that if 3 series are done it is indifferent to doing it at one speed or another”. The conclusions and practical applications are, to say the least, strange: why does a series performed at high speed produce a greater strength gain than a series at low speed and when doing three series there are no differences?

The design problems that have been commented could be at the base of some contradictory and unexplained results. Only two probable explanations are pointed out, which are not given in the text of the study:

1) the probability that the necessary progressive similarity in the speed of execution of all the groups when performing the exercises until failure has caused the greater equality in the stimulus at the end of three series than having done only one series,

2) the probability that only 2 minutes of recovery between series is a very short recovery time and could have caused greater fatigue in the “fast” group than in the slow group, since at a higher speed of execution for the same number of repetitions , the greater the fatigue (González-Badillo et al, 2014; Pareja-Blanco et al., 2014), which could have canceled out the probable greater effect produced by execution at higher speed. A 4-5 minute recovery after efforts to failure (if they were real) would most likely have modified the effects.

The probability that carrying out movements at the maximum possible speed is more harmful for physical and sporting performance than doing them at non-maximum speeds can be explained by the numerous advantages that are observed when actions are carried out at the maximum possible speed.

It has been observed that performing exercises at very high speed, high concentrations of testosterone are reached (Crewther et al., 2006). It has been proposed that this type of training could demand a high consumption of testosterone, so it is likely that a high absolute speed of execution has an effect on this hormone.

performing exercises at very high speed of execution in training, high concentrations of testosterone are reached

Indeed, the high effect on testosterone when performing exercises with light loads (30-50% of 1RM) (Crewther et al., 2006) can be explained by the fact that this hormone not only contributes to the development of fast fibers, Rather, it influences the functioning of these fibers when performing high-speed actions, such as jumping or sprinting (Viru 8 Viru, 2005).

The speed of execution could influence both the type of fibers recruited and the degree of metabolic stress. The greater speed of execution would allow the recruitment of fast fibers, and the slower speed could allow greater hypertrophy due to greater metabolic stress. However, for the same number of repetitions, not to failure, performing the movement at the maximum speed possible tends to generate greater fatigue and greater metabolic stress than doing it at 50% of maximum speed (Pareja-Blanco, Rodríguez-Rosell , Sánchez-Medina, Gorostiaga, González-Badillo, 2014), apart from offering better results in strength.

Training at very low speeds does not seem to be the most positive for improving strength and hypertrophy (Neils, Udermann, Brice, Winchester, McGuigan, 2005; Toigo 8 Boutellier, 2006).

Carrying out actions at the maximum speed possible generates rapid calcium release and withdrawal processes, which corresponds to a calcineurin (Cn) inhibition signal, which is considered a critical regulator in the calcium-derived signal cascade. to the genetic system for the expression of fast or slow fibers.

Specifically, Cn has been considered as an activator of slow fibers and an inhibitor of fast fibers (Chin et al., 1998). When the efforts are of short duration and intermittent, which require rapid and high release of calcium and rapid withdrawal of the same, the activity of Cn is inhibited and fast fibers are expressed, which are determinant for performing actions at high speed, which characterizes to most sports disciplines.

When displacing a load at the maximum possible speed, the stimulus frequency reaches its maximum values, which plays an important role in the slope of the force-velocity curve or RFD. In fact, when faced with different loads (absolute or relative), the higher the speed, the lower the force peak can be reached, but the greater frequency of stimulation is necessary to achieve it (de Hann, 1998).

In addition, the greater the slope of the force-time curve, the more the force threshold for recruiting MUs is reduced (until reaching the zero value of force) and the greater the number of MUs recruited (Desmedt and Godaux 1977). According to Desmedt and Godaux (1979), this could be applied to high speed concentric actions such as throws and jumps and when moving a load at the highest possible speed.

In addition to promoting faster motor unit recruitment, high-velocity training allows for more frequent double unloading (doublets) and an increase in the motor unit unloading rate, improving force production in unit time (Van Cutsem et al., 1998), which may be the basis of a greater improvement in performance when training at the maximum possible speed.

Executing the movements at the maximum speed possible allows a greater recruitment of fast fibers, improvement of the stimulus frequency and the possibility of reaching a greater slope in the force-time curve.

Therefore, the execution of the movements at the maximum possible speed allows a greater recruitment of fast twitches, the improvement of the stimulus frequency and the possibility of reaching a greater slope in the force-time curve, all of which is decisive in performance. sports in general, and especially when it is necessary to carry out actions at high speed values ​​or at the maximum possible speed.

In the article on training to muscular failure The design and results of two studies on TBT, one with the bench press exercise (González-Badillo et al., 2014) and the other with the squat (Pareja-Blanco et al. 2014), have been described in which actually compares the effect of performing all the repetitions at the maximum possible speed or doing it at half that speed.

In this article, the importance of the execution speed of the first repetition for the dosage, control and evaluation of strength training is exposed in an orderly manner in order to give the opportunity to become aware of the repercussion of the appropriate application of this variable in the development of everything related to strength training.

In this series of articles we deal with some of the most important concepts of strength training, collecting notes from the recently published book Strength, Speed ​​and Physical and Sports Performance written by renowned researchers Juan José González Badillo and Juan Ribas Serna.

SUMMARY

• Speed ​​control comes to overcome the series of inconveniences presented by the use of RM and XRM or nRM in the dosage of training and in the evaluation of its effect.
• It has been confirmed that each percentage of 1RM has its own speed for each exercise. This speed is very stable for the same person when their performance changes, and very similar between people, even when the level of performance between people is very different.
• If the average or average maximum propulsive velocity with which a mass displaces can be measured, by applying these equations we can obtain the percentage of the RM that said mass represents.
• The speed of the first repetition of the series serves to determine with what relative load the subject is training, as well as to determine what has been, and continues to be, the effect of training each day, what has been the evolution of the maximum intensity used every day, and what has been the pre-post training effect…
• The speed with each percentage is very similar between people with a very different level of performance.

Indeed, faced with all these inconveniences, it is necessary to find an appropriate solution. If the training schedule is nothing more than the expression of a series or ordered succession of efforts that are dependent on each other, and the effort is the actual degree of demand in relation to the current possibilities of the subject, which represents the nature of the effort, the appropriate solution will be to be able to measure with high precision the character of the effort. This is achieved if it is known:

• The Degree of Effort that represents the first repetition of a series.
• The Degree of Effort that represents the loss of speed within the series.

This article will deal with these two factors as key elements of the quantification, dosage, control and evaluation of the training load and its effects.

The speed with each percentage of the RM and its stability. Degree of Effort that represents the first repetition of a series

A few years ago Professor González-Badillo wrote: “if we could measure the maximum speed of movements every day and with immediate information, this would possibly be the best point of reference to know if the weight is adequate or not”… ” You could also record the maximum speed reached by each lifter with each percentage, and based on this, assess the effort” (González Badillo, 1991, p. 172). Currently, it can be affirmed that these hypotheses-proposals have been confirmed.

In the year 2000 these authors presented the first data in relation to speed with each percentage (González-Badillo, 2000). Subsequently it has been confirmed that each percentage of 1RM has its own speed. This speed is very stable for the same person when their performance changes, and very similar between people, even when the level of performance between people is very different (González-Badillo & Sánchez-Medina, 2010).

Therefore, throughout the approach to the application that has the knowledge of the speed of the first repetition under an absolute load, it is assumed that, although the value of 1RM can change between different days, the speed at which that each percentage of the MRI is performed is very stable.

For example, in the bench press exercise, whenever a well-executed progressive test is carried out until reaching RM and we verify the relationship between the percentages represented by the different displaced masses and the speeds at which they have been displaced, we found a very high fit to a second degree polynomial trend curve.

This kind of high fit has occurred in all the well-performed tests that have been carried out by the authors in the last 25 years. It must be taken into account that the concentric phase in the bench press test must be performed after a brief pause (1-1.5 s) after the eccentric phase, with the support of the bar on the chest or on a support .

The concentric phase must be performed without countermovement and the speed of execution must be the maximum possible before each mass. One should start from low relative intensities, equivalent to 15-20% of the RM. A high value of the R2 allows estimating (applying the corresponding regression equations) the speed with any percentage of the RM with a very small error.

The relationship between the different percentages and their corresponding mean propulsive velocities in the bench press exercise is expressed in Figure 1. The series of points that resemble a line—that appear at 100% MR height, rounded by a red circle, are the MR velocity values ​​for each of the subjects. Naturally, there are subjects whose average MR speed is above average and others below average. it is not possible for all subjects to perform their one-repetition maximum at the same speed.

Figure 1. Relationship between the RM percentages and their corresponding mean propulsive velocities. The 1596 data from 176 subjects are practically within the De 95% interval, with an R2 of 0.98 and an estimation error of 0.06 (González-Badillo and Sánchez-Medina)

These differences in the speed of the RMs are responsible for the points going slightly above the mean line or below. That is, the speed of each percentage tends to depend on the speed with which the RM was reached. If with the data of figure 1 the average propulsive velocity (VMP) is considered as an independent variable, we obtain an R2= 0.981; an estimation error of 3.56% and the following regression equation %1RM = 8.4326 * VMP2 – 73.501 * VMP + 112.33, where VMP is the mean propulsive velocity.

If we took the VM speed as a reference, not the VMP, the data would be the following: R2 = 0.979; an estimation error of 3.77% and the equation: %1RM = 7.5786 VM2— 75.885 VM + 113.02, where VM is the average speed of the entire route.

These equations make it possible to estimate with considerable precision the percentage represented by any absolute load once the VMP or MV at which it has moved is known, provided that the speed of movement has been the maximum possible for the subject.

It is preferable to take the average propulsive speed as a reference, since it better represents the true performance of each subject, by eliminating from the measurement the braking phase that occurs when the loads are medium or light. But if the speed meter used does not register this speed value, the average speed can be used, but taking into account that the speeds with each percentage will be slightly lower under light and medium loads if MV is measured than if MP is measured.

If the average or average maximum propulsive velocity with which a mass displaces can be measured, by applying these equations we can obtain the percentage of the RM that said mass represents.

Once you know the percentage that a given mass represents, you can estimate the RM at any time without the need to measure it, although knowledge of the RM is not necessary to dose the training or to assess its effect. Unfortunately, there are many “studies” that have been devoted to estimating the RM in some exercises, when really the value of the RM, when talking about the training load, practically and totally loses its “bad” application if we handle it properly the information that the knowledge of the speed of execution offers us.

According to the regression equation shown in figure 1, the average propulsive velocity that would correspond to each percentage of the RM is presented in figure 2.

Figure 2. Mean propulsive velocity corresponding to each percentage of the RM in the bench press exercise (González-Badillo & Sánchez-Medina, 2010)

It is very important to verify that the relationship between speed and load is stable, that is, if these values ​​remain very similar when the subjects change their performance, since this is the basis for applying the speed of the first repetition of the exercise. series for reference.

The speed of the first repetition of the series is used to determine with what relative load the subject is training., as well as to determine what has been, and continues to be, the effect of training each day, what has been the evolution of the maximum intensity used each day, and what has been the pre-post training effect…

The training effect is assessed by speed changes at the same absolute loads at any time, which can be before and after a training period or in each of the training sessions. All this constitutes part of the maximum and best information that a coach can have to know what he is doing and improve his training methodology.

The speed of the first repetition of the series is used to determine with what relative load the subject is training.

In this sense, a series of data are provided that serve as a reference to confirm that, indeed, the speed values ​​with each percentage are very stable, even if the performance of the subjects changes and even if the subjects are of a very different level of performance. . A first example of this stability is presented in figure 3, in which the results of two measurements of the speeds are compared with each percentage of the RM in the bench press exercise.

first study: analysis of velocity in the bench press exercise

The values ​​for the year 2010 are the same as those in Figure 2. These values, which were recorded in the years 2006-2007, were obtained with subjects other than the participants in the 2014 study, whose data were recorded in 2013-14, 6-7 years apart. It can be seen that the speed values ​​with each percentage are practically the same. These data help to confirm that the speed with each percentage remains stable, even though the data is obtained with completely different samples.

Figure 3. Velocity with each percentage of the RM in the bench press exercise in two different groups of subjects and several years apart in the recording of the data. It can be seen that the differences (upper part of the figure) in the speeds do not exceed 0.02 m-s-1. (Figure by Sánchez-Medina).

Continuing with the examples, in the study by González-Badillo and Sánchez-Medina (2010), carried out with the bench press, it was verified that after a training period of an average of six weeks, 56 subjects, who improved as averaged 9.3% of their RM on the bench press, they kept pretty much the same velocity with each percentage. These data allow us to confirm that not only each percentage of the RM has its own speed, but that this speed is very stable when the performance is modified.

Not only does each percentage of the RM have its own speed, but this speed is very stable when changing performance.

Table 1 shows the average speed values ​​with each percentage before and after the training of the 56 subjects. The maximum difference is 0.01 m*s-1. It should be noted that these subjects trained according to their criteria, without any instruction, which means that the training sessions must have had very different characteristics.

Tabla 1. Mean propulsive velocity and standard deviation with each percentage of the RM in the bench press in 56 subjects before (T1) and after (T2) a training period of 9 weeks on average (González-Badillo & Sánchez-Medina, 2010).

From the individual data of these 56 subjects we can extract additional information that allows us to continue reinforcing the stability of the percentage-speed of execution relationship. Several representative cases are discussed below.

Figure 4 shows the data of one of the subjects, who was very expert in training the bench press exercise, and who clearly improved his 1RM: 14.8%. If we look at the figure of test 2, T2 (red line), apparently, the speeds with each percentage are lower than those of test 1, T1 (blue line). This would go against the hypothesis that holds, but these data are not comparable, so they really do not go against the hypothesis.

The explanation is in the speed with which each RM has been achieved. In T1 the velocity was 0.17 m*s-1, while in T2 it was 0.06 m*s-1 (both values ​​in the red circles at the bottom of the figure). These two RMs cannot be compared, because they have been achieved at clearly different speeds, and, therefore, their speeds with each percentage cannot be compared either: the lower the speed with which the RM is achieved, the lower the speed with each percentage.

If the difference between the speeds of the RMs is equal to 0.03 m*s-1, we can already begin to observe a tendency to be lower than the speeds corresponding to the RM reached at a lower speed, and if the differences are greater than 0.03 m*s-1, the two RMs should no longer be compared.

Figure 4. Evolution of speed with each percentage in a subject who exceeds his result by 14.8% but performs his RMs at very different speeds (see text for further explanation).

It must be taken into account that the fact that the two RMs should not be compared is not due to the fact that one of them is considered a “true” RM and the other is not, since both are within the velocities of the RM of this exercise, whose average value may be around 0.17-0.18 m*s-1 (González-Badillo, 2000; González-Badillo and Sánchez-Mediná 2010), but to the fact that there is a high difference between them .

However, despite the fact that in T1 the speed of T2 almost triples, the differences in speeds with each percentage do not exceed, in the worst case (low percentages), 5% of the RM since the difference in speed each 5% is 0.08-0.09 m*s-1, a difference that is not exceeded in any of the percentages calculated, from 30 (0.09 m*s-1 difference) up to 95%.

Conclusions of the first study

As a result of the analysis of this case, at least the following practical applications can be deduced:

1) MRIs whose measurement speeds are greater than 0.03 m*s-1 cannot be compared, although in extreme cases such as the one we are presenting, in which the speed of the MRI is tripled, the effects do not go beyond one difference of 5% of the MR for the same speed of the same subject,

RMs whose measurement speeds are greater than 0.03 m*s-1 cannot be compared,

2) given the high probability that two RM are measured at different speeds, it is not advisable to ever measure the RM (it can be estimated, if necessary for something, as we will see in another section) and

3) only by measuring the speed with which the MR is reached, it is possible to have the necessary information to avoid the errors made with high frequency when measuring this variable.

Here we have to remember that the true RM will never be known, but some RMs can be considered as “true” or representative of the true RM when measured at velocities of their corresponding RM values. The more the measured speed (always higher speeds) deviates from the MR values ​​of an exercise, the more “false” is the RM measurement. This, once again, can only be known if the speed with which the exercise is performed is measured.

The errors to which we refer in the practical application 3) refer to the fact that most of the changes, such as the improvement or worsening of the results observed when measuring 1RM, are false, because if a subject, for example (it is a case real), lifts 82 kg in T1 and 92 kg in T2, it can be concluded after doing the calculations, that the subject has improved his mark by 12%.

But if one takes into account that this subject did the MRI of T1 at 0.33 m*s-1 (real data) and that of T2 at 0.2 m*s-1, the conclusion is false, because if the subject could have done the MRI at T2 at 0.2 m*s-1, it could also have been done at a very similar speed (0.2 + 0.02 m*s-1) at T1.

This would mean that he could have lifted a weight greater than 82 kg, then the improvement has not been, by any means, 12%. As an example, and making a few small calculations, if we suppose that the T1 would have done it at the same speed as the T2, at 0.2 m*s-1, and taking into account that every 5% the speed change is 0.08 m*s-1, the subject in T1 would have lifted approximately 88 kg, 8% more, given that the difference between T1 and T2 is 0.13 m*s-1.

Therefore, the improvement would have been approximately 4-5%, far from the apparent 12%. This example shows one more of the important applications that measure the speed of my execution has, although this application is better not to use it, because the RM should never be measured.

second study

A new example is shown in Figure 5. This subject improved his result by 11.8% and the velocities with the MRI presented a small difference of 0.02 m*s-1. As can be seen, the velocities with each percentage remained practically stable, with a maximum difference of 0.02 m*s-1, that is, the equivalent of a maximum difference of 1.25% of the RM with respect to T1.

Also, in this case, the speed in all percentages tended to increase slightly, so it could be said that the subject slightly improved (because the change can only be very small) his strength deficit. This slight improvement in speed can be explained because the subject, after his experience in doing the tests, decided to train by performing each repetition at the maximum speed possible, when previously he did it slowly voluntarily.

Therefore, it is confirmed that despite a considerable improvement of almost 12% (in this case we can say that it is real), the speeds with each percentage remain stable.

Figure 5. Evolution of speed with each percentage in a subject who exceeds his result by 11.8% and performs his RMs at very similar speeds

Figure 6. Evolution of speed with each percentage in a subject who does not exceed his result and performs his RMs at very similar speeds

Figure 6 shows an example of a subject who did not improve his result and that the speeds with each percentage were practically the same in both tests, although T2 was performed at a speed of 0.03 m*s-1 higher than the from T1.

But, precisely, this small speed difference could explain, on the one hand, why the speeds in T2 are minimally higher (0.01-0.2 m*s-1), and on the other, that it really cannot be said that the subject It did not improve its performance at all, since it improved speed by 0.03 m*s-1 with the same load (110 kg). This assessment can only be done if the speed of execution is measured

Figure 7 shows the case of a subject who improved his RM by 7.9%, who performed his two RMs at the same speed, but the speed with each percentage up to 75% of the RM tended to decrease. This was the only case, out of 56, that departed from what we have been maintaining. But when consulting the subject about his way of training, he stated that he trained slowly voluntarily.

Training slowly voluntarily may tend to proportionally decrease performance with loads moving at high speed and thus increase the strength deficit under these loads.

This way of training may tend to proportionally decrease performance with loads that are moved at high speed and thus increase the strength deficit in the face of these loads. Despite this circumstance, it can be observed that the decrease in speed with light loads did not exceed 0.06 m*s-1, which means that, in the worst case, the maximum difference in speed with each percentage in T2 with respect to T1 it was equivalent to 3.7% of the OR.

Figure 7, Evolution of speed with each percentage in a subject who exceeds his result by 7.9% and performs his RMs at the same speed.

In Table 2, made up of two groups of data, with a total of 20 subjects (the first 20, by random order, in the list of 56 subjects who repeated the tests) we can see the speed at which they reached their RMs. in tests 1 and 2, the average speed of the percentages from 40 to 90% of the RM, the maximum and the minimum difference obtained in the set of these percentages and the change in performance.

It is observed that the average speed from 40 to 90% follows the same trend as the difference between the speeds of the RMs. Only in the cases of JG and PC subjects, the maximum difference in some percentage is equivalent to a 5% difference with respect to the RM.

It can be seen that there are 12 cases of improvements ranging from 8.3 to 21.23% with an average of 13.9%, in which the maximum difference in speed with the percentages from 40 to 90% is 0.05 m*s-1 in the two subjects mentioned above (JG and PC), one case with 0.04 m*s-1 (V) and the rest with 0.03 m*s-1 or less. This data set again reinforces the stability of the speed of each percentage, even if there are important changes in the performance of the RM.

Table 2 Velocity values ​​with the RM (vel_RM), average velocity of the velocities with the percentages between 40 and 90%, maximum (max_diff), and minimum (min_diff) velocity difference with each percentage between tests 1 and 2 and change in performance (Change_RM) of the first 20 subjects in the list of 56 who repeated the tests.

Table 3 shows the speeds with the RMs, mean speeds from 40 to 90% of the RMs, differences in the speed with the RM and the differences between the mean speeds with the set of percentages in two tests for the same subjects included in Table 2. Taking the set of data included in the yellow columns, it is possible to calculate the relationship between the differences in the speed of the MRI and the differences in the average speed of

Tabla 3. Speeds with the RMs (Ve_1RM), mean speeds of the percentages from 40 to 90% of the RMs (Vel_mean_%), differences in speed with the RM (Dif_V_1RM) and the differences between the mean speeds with the set of percentages in the two tests (Dif_V_mean) of the same subjects included in Table 2.

Figure 8 shows the relationship between the differences in the speed with which the RMs were achieved (axis X) and the differences in the mean speed in the percentages of the RM from 40 to 90% (axis Y).

It can be seen that 12 of the 20 cases are found in the positive quadrants of the coordinate axes, which are the ones that correspond to the trend that indicates that the speed of the MRI determines the speed with each percentage, that is, the higher is the speed of the RM the greater the speed tends to be with each percentage.

There are three cases in which the velocities with the MRI were the same (points that coincide with the Y axis) and the velocities with the percentages changed minimally, between 0.03 and 0.02 m*s-1.

A case in which, having produced a decrease in the speed of the MRI in T2 by about 0.07 m*s-1, the average speed of the percentages was identical (point located on the X axis). This case can be considered as an example of a subject improving his strength deficit: although a lower MR speed should correspond to a slightly lower speed with each percentage, the subject maintained a speed.

There are two cases in the lower negative quadrant in which, having slightly increased the speed with the MR around 0.02 m*s-1, the speed with the percentages decreased by 0.02 m*s-1, which suggests that it was produced a minimal increase in strength deficit.

Finally, there is a case in the upper negative quadrant in which a subject who performed his MRI speed at a slower speed (0.02 m*s-1) at T2 slightly increased speed with percentages (0, 01 m*s-1).

As can be deduced, the stability of the speed with each percentage is ratified. The changes are minimal and the trend between the speed with the RM and the speed with each percentage is fulfilled in a remarkable way.

Figure 8. Relationship between the differences in the speed with which the RMs were achieved (axis X) and the differences in the mean speed in the percentages of the RM from 40 to 90% (axis Y).

It must be taken into account that the subjects cannot behave like perfect “machines”, but that they respond in a way that is not exactly the same before a series of progressive loads when trying to perform a 1RM test. This means that under absolute load the performance is not exactly the same as under the immediately higher absolute load.

That is to say, if a subject achieves a certain speed at an absolute load, not always at the load immediately above, which will represent a certain percentage increase, he will respond by reaching exactly the speed that would correspond to that percentage increase in load. This can cause the subject’s force or load-velocity curve to adjust more or less to his true performance capacity, giving rise to small deviations from the model that represents the population to which the subject belongs.

Does performance level affect speed?

To continue adding elements to confirm the stability of the speed with each percentage, it could be assessed whether the speed with each percentage is similar or not between people with different levels of performance.

From the results of the study it can be deduced that, indeed, the speed with each percentage is very similar between people with a very different level of performance. By dividing the group of 176 cases into four groups based on their relative MR (RM * body weight-1), the mean speeds from 30 to 95% of the RM were 0.76, 0.77, 0.77 and 0.73 m*s- 1 (table 4), in this order, from the group with the lowest performance to the most expert group, respectively.

Therefore, the average speed is almost the same despite the performance increase considerably. Consider that the subjects with the lowest performance did not get to lift a weight equivalent to their own body weight in the bench press, while some of the most expert subjects came to lift twice their body weight or approached this mark.

Less performing subjects failed to bench press their own body weight, while some of the most experienced subjects lifted twice their body weight

Only the highly expert group, the one with the highest performance, experienced a minimal statistically significant average reduction in speed with each percentage compared to the others. However, a tendency to decrease speed is not even observed as performance increases, since the second group with the lowest average speed is that of the less expert subjects (0.76 m*s-1).

In addition, the statistical differences in this case are not relevant in practice, since the absolute difference between the most expert group and the least experienced group is not even 0.03 m*s-1 (specifically, 0.027 m*s- 1), which would be equivalent to a -1.69% difference in the RM percentages between the two for the same speed.

Tabla 4. Relative strength (relative strength), mean speed with percentages from 30 to 95% of the RM (mean test velocity) and speed with the RM (V1RM) of four groups of cases (subgroup) formed according to their performance.

However, if these results are analyzed in greater depth, it is concluded that these differences are not real. Responding to the question formulated in the lower part of Table 4, the apparent lower speed with each percentage of the most expert group is due to the fact that the average speed with which the components of this group reach their RM is slightly less than that of the others (0.045 m*s-1 with respect to the group with the lowest performance, and 0.019 and 0.014 m*s-1 for the other two groups).

This fact causes that, necessarily, the speed with each percentage tends to be lower, which comes to ratify, once again, what has already been revealed previously. Thus, the slight decrease in speed with each percentage of the top performing group in the bench press exercise is due to the tendency to decrease speed with RM in extremely expert subjects.

It is reasonable to accept that these subjects are able to make the most of their own strength potential, because they have more confidence in their possibilities and better technique when executing the exercise. It should be noted that, given the characteristics of the subjects in this study, the generalization of these data leads us to be able to apply them to the entire population, since in the group there are subjects who lift from less than 90% of their body weight up to subjects lifting twice their body weight.

This means that any young person practicing any sport or simply using strength training can be included here. Therefore, this is one of the few exercises that would really allow us to assess our strength-speed “profile”.

If we execute the exercise well, we will be able to know to what extent our performance in this exercise is in the average of the population in terms of speed with each percentage, if it is slightly above or if it is slightly below, or even if it is below. above or below in some areas and not in others of the force-velocity curve or not.

However, to make these assessments, one must also take into account the speed at which MR is reached. But the stability in the relationship between the percentages of the RM and their corresponding speeds also occurs in any exercise in which the measurements have been made well.

Table 5 shows the data corresponding to the complete squat exercise. The group consisted of 80 subjects. The differences in performance are important, from 93 to 126 kg on average, with coefficients of variation from 12 to 18%, and some subjects lifting more than twice their body weight (1.57 to 2.17 range in the highest performing group).

Therefore, we can admit that it is a sample that includes a range of performance in which a wide population of athletes can be found.

the average speed of all the percentages is practically the same

However, the mean speed of the set of percentages (mean test velocity) is practically the same (0.873, 0.867 and 0.865 m*s-1) The speeds with the percentage examples included in the table are practically the same in the three groups , existing between 0.01 and 0.02 m*s-1 as a maximum difference. The MRI speed of each group is practically the same as that of the others, and the same as that indicated in the year 2000 (González-Badillo, 2000). No significant difference is observed in any of these speed values.

Tabla 5. Comparison of the mean speeds of the tests with percentages from 30 to 95% of RM (mean test velocity), mean propulsive velocity with different percentages (MPV), mean propulsive velocity with RM (MPV with 1RM) in three groups formed based on their vative performance with respect to body weight (RSR) in the full squat test. The effect size is represented by the “eta” statistic (effect size n2) (Sánchez-Medina et al., 2017).

Therefore, In an exercise as different from the bench press as the squat, the stability of the speed is confirmed with each percentage, although the performance of the subjects is very different. It has been indicated that the speed with each percentage is dependent on the speed with which RM is reached. This tendency has been verified when analyzing the different examples of performance with the bench press exercise.

Although this tendency not only occurs in the same exercise when the speed of the RM changes due to its faulty measurement, but naturally also occurs between the different exercises, because each exercise has its own speed, and different from that of the others. , from his RM (González-Badillo, 2000).

In this article, published with data recorded in the 1990s, it was already commented that the speed with 40% of the RM of the bench press was 1.15 m*s-1, which differs in only two hundredths of a m*s-1 of the current data (1.13 m*s-1), and the squat had a speed of 0.93 m*s-1′ with 64.3% of the RM, practically the same speed that is currently proposed (0.92 m*s-1 with 95%. see table 6).

each exercise has its own speed, and different from the others

Likewise, it was confirmed that the speed with each percentage depended on the speed of the RM, because the snatch, with an average RM speed of 1.04, the speed of 1.15 m*s-1 was obtained with 91% of the RM, while, as we have indicated, this same speed of 1.15 m*s-1 with the bench press belonged to 40% of the RM, with a speed of his RM of 0.2 m* s-1. The same was the case with the power clean: 1.09 m*s-1 for 87% of the RM and a velocity of his RM of 0.9 m*s-1.

The fact that the speed with each percentage depends on the speed of the RM is so evident that we can say that it is “truth”, although this does not prevent someone from occasionally questioning it.

It is evident that if the speed of the RM of an exercise is, for example, 0.2 m*s-1, the speed of 95% of the RM of that exercise should be approximately 0.26-0.28 m *s-1, and 90% should be 0.32-0.34 m*s-1 and so on, but if the RM speed of the exercise is 1 m*s-1, 95% of the MRI will have to be a few hundredths of a meter per second faster, for example, 1.08-09 m*s-1, more or less, but always very far from 0.26-0.28 m*s- 1 of the exercise whose MRI velocity was 0.2 m*s-1.

Naturally, this is confirmed when the speeds of different well-measured exercises are compared with different speeds of their own RMs.

Table 6 shows the speed data with each percentage corresponding to four very common exercises in strength training (bench press: González-Badillo and Sánchez-Medina, 2010; pull-ups: Sánchez-Moreno et al., 2017; squat : Sánchez-Medina et al., 2017; rowing table: Sánchez-Medina et al., 2014).

Tabla 15.6. Speed ​​with each percentage in the bench press, pull-ups, squats and plank rows.

Table 6 shows that the speed values ​​of each percentage increase as the speeds of the RMs increase. The relationship between the speeds of the RMs and the average speed of all the percentages from 65% to 100% is almost perfect (r= 0.97; p < 0.05).

It is very relevant that with only 4 pairs of data the correlation is statistically significant. Therefore, it is confirmed that, indeed, the speed with each percentage is dependent on the speed of the RM of the exercise, as well as the differences in the speed of measurement of the RM when it is measured more than once within each exercise. .

As a synthesis of all the above, it is confirmed that training can be controlled through the speed of the first repetition in the series, provided that it is done at the maximum speed possible, and this is based on the fact that we can start from the assumption that if Although the value of 1RM can change between different days, the speed at which each percentage of the RM is performed is very stable.

It is confirmed that the training can be controlled through the speed of the first repetition in the series as long as it is done at the maximum possible speed.

Therefore, speed control can inform us with high precision about what real percentage or what effort is being made at each moment. Therefore the own speed of each percentage of 1RM determines the real effort. This means that the speed of the first repetition of a set determines the degree of effort that the load represents.

Thus, the training load (mass) can be determined by the speed of the first repetition. If this is so, what should be programmed is not the percentage of 1RM or an XRM, but the speed of execution of the first repetition of the series. Note: for convenience or to be more intuitive, it could be programmed by means of the RM percentages, but the absolute loads (masses) that correspond to those of the percentages would always be determined through the speed of the first repetition of the RM. series, not by the result of the arithmetic calculation of the percentage.

conclusions

From all of the above, it can be deduced that using the speed of execution as a reference to dose and control the training far exceeds what the percentage of 1Rm and XRM contributes. Therefore, the existence of a high stable relationship between speed and the different percentages of 1RM allows a series of applications such as those indicated below.

All the data that have been provided have been obtained and are applicable to men. For women, the corresponding speed values ​​have not yet been published, but laboratory data, in the publication phase, indicate that the speeds with each percentage are practically the same with women from a relative intensity of 45-50%, reducing approximately at 0.03, 0.04 and 0.06 m*s-1 with the intensities of 40, 35 and 30% of the MR, respectively.

the speeds with each percentage are practically the same with women

Knowing the speed of the first repetition (speed with each percentage) allows:

• Evaluate the strength of a subject without the need to perform a 1RM test or an XRM or nRM test at any time.
• Determine with high precision what real percentage the subject is using as soon as he performs, at the maximum speed possible, the first repetition with a determined absolute load.
• Estimate / measure the improvement or not in performance EVERY DAY without the need to perform any test, simply by measuring the speed with which an absolute load moves. If, for example, the difference in speed between 70 and 75% of the RM of a specific exercise is 0.08 m*s-1, when the subject increases the speed by 0.08m*s-1, with the same load absolute, there is a very high probability, almost 100% that the load with which you train represents 5% less intensity. Naturally, if what is produced is a loss of speed before the same absolute load (kg), we can be quite sure that the subject is below his previous performance, and in a proportion proportional to the loss of speed before the same load. absolute load.
• The measurement of the speed of the first repetition on a daily basis, just week before and after the training allows:
  • Know the degree and time of adaptation individually.
  • Discover the degree of disparity of the adaptive responses.
  • Check the effect of improving strength on other types of performance trained or not.

Regarding the speed of the MRI, it can be concluded that:

• The only way to be able to consider an MR as “true” or false is to measure the speed with which it is achieved.
• Two MR values ​​of the same subject cannot be compared if the values ​​of the speeds with which they have been measured are not the same or very similar.
• If the speeds at which the pre-post training RMs have been measured are different, with differences greater than or equal to 0.03 m*s-1, these RMs are not equivalent, so comparing the values ​​of the RMs (weights raised) pre-post training would lead to erroneous decisions, considering that there have been some changes in strength (in the MRI) that are not real.
• In addition, the speeds with each percentage would appear to be different, without meaning that they really are.

Regarding the assessment of the effect of training, it is concluded that:

• MRI is not necessary and should never be measured.
• The best procedure for assessing the training effect is to re-measure the speed reached at the same absolute loads that were measured in the initial test.
• This procedure is the most coherent and precise, since the effect of strength training is measured by the change in speed at the same absolute load or, as already indicated, the assessment of the training effect through changes in MR. , even in the not very probable assumption that the speeds with which the RMs are measured are the same or very similar, it would only inform us about the effect of the training before the maximum load (RM), but not before other lower loads

Other apps:

• Use strength training with all subjects, from children to the most advanced athletes or adults and older people who want to improve their health, without the need to do maximum effort tests (1RM, or XRM, for example) in any case.

The authors’ proposal, therefore, is that the mean propulsive velocity of the first repetition should always be used to program, dose and evaluate the training load and the performance of the subject.

In this article he focuses on the speed of execution as a reference for training programming, dosage and control. In the previous article on Character of Effort (EC) some ideas related to speed of execution have been introduced that may be useful.

In this series of articles we deal with some of the most important concepts of strength training, collecting notes from the recently published book Strength, Speed ​​and Physical and Sports Performance written by renowned researchers Juan José González Badillo and Juan Ribas Serna.

SUMMARY

• The speed at which each percentage of the RM is performed is very stable depending on each exercise.
• Loss of speed is shown to be an important predictor of metabolic and hormonal stress.
• For the same loss of speed, each person may have performed a different number of repetitions before the same load.
• Using the speed of execution as a reference to dose and control the training far exceeds what the 1RM percentage provides

A few years ago it was said: “If the maximum speed of the movements could be measured every day and with immediate information, this would possibly be the best point of reference to know if the weight is adequate or not”… “a certain decrease speed is a valid indicator for suspending training or lowering the weight of the bar”… “we could also have recorded the maximum speed reached by each lifter with each percentage, and based on this, assess the effort” ( González Badillo, 1991, p.172).

It is based on the assumption that although the value of 1RM can change between different days, the speed at which each percentage of the RM is performed is very stable. Therefore, speed control could inform us with more precision about what real percentage or what effort is being made at each moment. This hypothesis, proposed in 1991 (González Badillo, 1991, p. 172), when we said “we could also have recorded the maximum execution speed reached by each lifter with each percentage, and based on this, assess the effort… ”, has been confirmed, because each percentage of 1RM has its own speed (González-Badillo, 2000; González-Badillo and Sánchez-Medina, 2010).

Therefore, the own speed of each percentage of 1RM determines the real effort. This means that the speed of the first repetition of a set determines the degree of effort that the load represents. Thus, the training load (weight) is determined by the speed of the first repetition, therefore, what must be programmed is not the percentage of 1RM, but the speed of execution of the first repetition of the series.

But speed control not only allows us to know very precisely the true effort that a given load represents when doing the first repetition, but also allows us to know in what proportion or percentage speed is lost as repetitions are made within from the series.

And this is important because the loss of speed in the series is a highly valid indicator to know the degree of effort that the subject is making, since it presents a high relationship with indicators of the degree of mechanical, metabolic and hormonal stress caused by the exercise. training.

loss of speed is shown to be an important predictor of metabolic and hormonal stress

Thus, we found high relationships between the loss of velocity in the series and the loss of velocity with the load that was moving at 1 m/s before the effort, both in the bench press (1= 0.97) and in the squat. (r = 0.91), and with the loss of height (loss of speed) in the jump after the effort (r = 0.92), with ammonium (R* = 0.93) and lactate (r = 0.95-0.97) (Sánchez-Medina and González-Badillo, 2011).

Testosterone (r = 0.83), growth hormone (r = 0.82) and insulin (r = 0.88) are also discharged, and these relationships increase for ammonium (p = 0.94 -96) and lactate (p = 0.98) when using Spearman’s rank correlation coefficient (data from the same previous study, but not yet published. Sánchez-Medina’s Doctoral Thesis, 2010).

All these relationships indicate that the greater the loss of speed in the series, the greater the mechanical stress, that is, the greater the effort, at the same time that the loss of execution speed is shown to be an important predictor of metabolic stress and hormonal.

The question that arises at the moment is what should be the optimal loss of speed in each case. This question, of course, does not have an easy answer, but being able to formulate it and have the appropriate mechanical and physiological data available to try to find an answer is already a great advance. In fact, at this time we could give an indicative and useful answer for most of the subjects.

For example, ammonium is practically unchanged in the bench press and full squat exercises if the number of repetitions performed does not exceed half of the repetitions that can be performed (Sánchez-Medina and González-Badillo, 2011). That the ammonia remains at its resting values ​​means that the emergency pathway of energy production, which is responsible for the increase in ammonia, has not been put into operation.

This path consists of the fact that, given the high and continuous demand for energy, it is not enough to use ADP+CP to produce ATP and the system has to resort significantly to the use of 2 ADP (ADP+ADP) to produce ATP, which which leads to the production of adenosine monophosphate (AMP), inosine monophosphate (IMP) and the degradation into ammonia (NH3) and ammonium (NH4), hypoxanthine, xanthine uric acid, formation of free radicals and losses of purines, this supposes a loss nucleotides (Hellsten-Westing et al., 1993), which can lead to chronic ATP depletion and increased recovery time if sessions that significantly trigger these processes are frequently repeated (Stathis et al. ., 1994, 1999).

If we also know, from extensive practical experience, that doing half or less of the repetitions that can be performed produces notable improvements in muscular strength and sports performance, It would not be very advisable to frequently exceed (in some cases it would never be necessary) half of the repetitions that can be done in a series.

it would not be very advisable to frequently exceed (in some cases it would never be necessary) half the repetitions that can be done in a series

If we analyze the relationship between the loss of speed in the series and the number of repetitions performed, we can state that in the bench press exercise the loss of speed when half of the possible repetitions have been done is between 25 and 30% of the speed of the first repetition, and that in the complete squat the loss of speed of execution in the same conditions would be approximately 15-20%.

Therefore, if it is possible to know what degree of effort each percentage of speed loss means, the application of speed as a way of training control is very useful, probably the best procedure, using the mechanics way, to know with high precision and immediately the training load.

Knowledge of these data would allow not only to program the intensity or degree of effort based on the speed of the first repetition, but also to determine the degree of effort in the series, by being able to decide the loss of Speed ​​that is allowed in the series itself.

By way of example, at this time we can anticipate that in the exercise of the bench press, the relationship between the percentage of speed loss in the series (PPVS) and the average percentage of repetitions performed in the series (PMRR), for the intensities of 50, 55, 60, 65 and 70% of the RM is practically the same.

The percentage of repetitions performed for the same loss of speed must be 2.5% higher when the relative intensity is 75%, 5% higher for 80% and 10% higher for 85% (González-Badillo et al., 2017).

The data corresponding to the intensities between 50 and 70% appear in Table 1.

Tabla 1. Loss of speed in the series and average percentage of repetitions performed with intensities of 50 to 70% of the RM in bench press.

• PPVS: Percentage loss of speed in the series.
• PMRR: Mean percentage of repetitions performed.
• SD: standard deviation.
• CV (%): Coefficient of variation.

for the same loss of speed in the series, each person may have performed a different number of repetitions under the same relative load

It can be seen that, given the low CV values, the PMRR for the different percentages are practically the same. Therefore, when repetitions are performed at the maximum speed possible with any of these RM percentages, the percentage of repetitions performed for a given loss of execution velocity in the series can be known with considerable precision.

It should be remembered here that for the same loss of speed in the series, each person may have performed a different number of repetitions under the same relative load. This means an important advance in the precision to quantify and assess the CE in the series and training session. One more application of speed as a reference to dose and control training derives from the fact that each exercise has its own speed for its RM (González-Badillo, 2000).

The speed at which the RM of an exercise is reached determines its characteristics and its own training intensities for each objective.

Although, as we will see in later chapters, the load with which maximum power is reached is not relevant either for training dosage or for assessing its effect, these loads are determined precisely by the speed of the RM of each exercise. For example, the faster the speed with which the RM of an exercise is reached, the greater the percentage with which the maximum power is reached in the exercise.

There is a very high positive trend between the own speed with the RM in four exercises (snatch, power clean, squat and bench press) and the percentage of the RM with which maximum average power is reached (r = 0.94). (González-Badillo, 2000). It must be taken into account that these power values ​​are calculated through the product of the force and velocity values ​​provided by a linear velocity or position meter, in which the force is determined by the equation F = m( g+a), and the speed is measured directly by displacing the charge (mass).

The speed at which the RM is reached can range from less than 0.2 m/s in the bench press exercise to values ​​close to 1 m/s in the power clean or snatch. These observations confirm that, depending on the exercise with which you train, the same percentage can mean a very different magnitude and type of load, and that to obtain the same effect, you would have to use different percentages.

For example, if a subject intended to train with the maximum average power load in the bench press, he would have to train with 37-40% of the RM, while in the power clean he would have to train with 87% of the RM. Therefore, if we train both exercises, for example, with 80% of their respective RMs, in the case of the bench press we will be training with a load well above that with which maximum power is reached and in the case of the power clean with a load below that of maximum power.

an exercise like the full squat should never be trained with loads greater than 80% of the RM

However, and use this idea to better understand the consequences of, for example, “training with the maximum power load” in all the exercises, a training with 37-40% of the RM in the bench press, with 6 -8 repetitions per series, it is a very light effort that anyone can do at any time, and its effect, load and The degree of fatigue would be very low, however, training with 87% of the RM in a clean exercise is a significant effort, which is very close to the RM of the clean exercise.

Another example could be the following: for the same subject or group of subjects practicing a sport, an exercise like the full squat should never be trained with loads greater than 80% RM (personal suggestion based on extensive experience and results of competition studies), while this same group of subjects could always train, from the beginning of their sporting life, at least with loads equal to or greater than 75-80% of the real RM in the power clean exercise.

These differences in training loads are due, especially, to the fact that the speeds of the RMs of both exercises are very different, much higher in the power clean than in the squat.

From all the above it follows that use the speed of execution as a reference to dose and control the training It far exceeds what the 1RM percentage provides and comes to offer the same contributions as the Character of Effort (it really is another way of applying the CE) but with a much higher precision and eliminating the risk of subjectivity.

Therefore, the existence of a high relationship between speed and the different percentages of 1RM, as well as between the loss of speed in the series and the percentage of repetitions performed in the series allows:

• Evaluate the strength of a subject without the need to perform a 1RM test or an XRM test at any time.
• Determine with high precision what actual percentage of 1RM the subject is using as soon as they perform the first repetition with a given load at the maximum speed of execution possible.
• Program, dose and control training with high precision through speed, and not through a percentage of 1RM.
• If the speed is measured every day, it can be determined if the load proposed to the subject (kg) faithfully represents the true degree of effort (% of real 1RM) that represents the first repetition and the degree of effort that represents the number of repetitions performed (valued for the loss of speed in the series).
• Use strength training with all subjects, from children to the most advanced athletes or adults and seniors you intend. improve your health, without the need to do maximum effort tests (1RM, or XRM, for example) in any case.
• Estimate the improvement in performance each day without the need to perform any tests, simply by measuring the speed with which an absolute load moves. YES, for example, the difference in speed between 70 and 75% of the RM of a specific exercise is 0.08 m/s, when the subject increases speed by 0.08 m/s under the same absolute load , the load with which he trains will represent 5% less than the RM of the subject at that moment, which, naturally, will have increased in value. Naturally, if what is produced is a loss of speed under the same absolute load, we can be quite sure that the subject is below its previous performance, and in an average proportional to the loss of speed.
• Estimate, through the loss of speed in the series, the percentage that represents the number of repetitions performed with respect to those achievable under any load.
• Being able to calculate the Effort Index, probably the best indicator of the degree of effort and fatigue that can be used to estimate these training variables.

Therefore, as we have indicated, what is programmed or should be programmed is not the percentage of 1RM, but the speed of execution of the first repetition of a series (Of course, if we associate the percentages with their corresponding speeds, it would be indifferent to use one procedure or another) and the loss of speed in the series allowed. The speed with each percentage of 1RM is not modified or it does so in a very slight way when the subject modifies the value of his RM after a period of training.

What most determines the slight speed changes between a test and a post-test with each percentage of 1RM, if they occur, is the speed with which the RM is performed and measured (González-Badillo and Sánchez-Medina , 2010), in such a way that two MRIs could not be compared if they were performed at different speeds. But this problem disappears if, as we have indicated, we never measure the RM, neither to take it as a reference to program the training nor to assess its effect, but instead we use the speed and speed changes before the same loads for both objectives.

what is programmed or should be programmed is not the percentage of 1RM, but the speed of the first repetition of a series

Our proposal, therefore, is that the average propulsive velocity should always be used to assess the training load and the performance of the subject (if necessary, the article Sánchez-Medina et al., 2010 can be consulted).

In this article an analysis of the guidelines on the organization of strength training through speed is made.

In this series of articles we deal with some of the most important concepts of strength training, collecting notes from the recently published book Strength, Speed ​​and Physical and Sports Performance written by renowned researchers Juan José González Badillo and Juan Ribas Serna.

SUMMARY

• During training, the load can be modified to adjust the degree of effort with the programmed relative intensity.
• For the same loss of speed in the series, in all cases we will have useful information to know with high precision what training we have done, what degree of effort
• In training organized through speed, a determined number of repetitions in the series is not programmed, but rather a loss of speed in the series given the load or relative intensity selected.

First of all, it is convenient to take into account some prerequisites, taking into account that:

• The use of speed aims to provide information on the control of the training load and its effects.
• This information allows us to know with high precision with what relative intensity you train and with what degree of effort in the series, as well as what the training effect has been.
• For this information to be useful, the movements must be performed at the maximum possible speed, although the different values ​​of execution speed are not associated with specific training objectives.

Daily adjustment of the absolute training load

During training, it is possible to decide whether or not to modify the absolute load when the degree of effort represented by the first repetition with said load is lower or higher than the one programmed.

This adjustment would be logical if we want to be consistent with the programmed actual load (we are only referring to the speed of the first repetition in this case), and would consist of increase or decrease the absolute load by 1 measure necessary so that the relative intensity with which you train equals the programmed relative intensity.

This control would contribute in a precise way to carry out the programmed training and not a different one, which is already a great advance in the training methodology. But this control does not ensure the good result of the training. And this can be due to two reasons:

1. to that we have been able to make wrong decisions when programming the effort, or
2. because the decision we’ve made—whether or not to change the absolute load—is wrong, or both.

However, for the same loss of speed in the series, in all cases we will have useful information to know with high precision what training we have done, what degree of effort (relative intensity and loss of speed) and what its effects are. This will allow us to make better decisions in the immediate future based on the data and real behavior of the athletes.

In practice, when we observe a discrepancy between the programmed effort (only speed of the first repetition in this case) and the one that means for the subject the displacement of the absolute load that said effort represents, three situations can occur:

1. that the load moves at a higher speed than expected,
2. moving at the expected speed, or
3. to do it at a slower speed.

Naturally, in all cases three decisions can be made: maintain, raise or lower the load. But not in all cases these alternatives would be equally logical and reasonable.

If the load moves faster than expected

In the first case, if the absolute load moves at a higher speed than expected or programmed, it means that the subject has improved performance compared to what he had at the beginning of the training cycle, so it can be stated that the subject is training with a relative intensity lower than programmed.

The apparently most logical decision would be to increase the absolute load to the extent necessary to match the expected relative intensity. This would make it possible to comply in a very precise way with the programmed training (it is assumed that the loss of speed in the series would always be as expected).

But it is likely that when a subject clearly improves his performance after training for a few sessions, the most effective decision is to maintain the progression of the absolute loads predicted, even though the relative intensities with which he trains are less than those programmed.

In this way, a progressive load would be maintained in absolute terms, although the relative load remained more or less stable or even tended to regress, which would indicate that the performance improvement is greater.

In other words, we propose that it is probable that when the improvement in performance is important, the progression of the absolute loads is sufficient, and very favourable, for the improvement of performance, although the relative intensity remains stable or even decreases progressively. This decision should be kept as long as the performance improvement is maintained.

In any case, the speed measurement will continue to inform us of both the performance progression and the degree of effort that has caused it.

IF the load moves at the expected speed

In the second case, if the load moves at the expected speed and more than 6-8 training sessions have passed, the situation becomes worrying, because this would mean that the subject has not experienced any improvement in performance.

In this case, it would be necessary to analyze all the possible circumstances that could explain the lack of positive response. If no reasons unrelated to the training itself are found (illness, personal problems, excessive work or study…) and the subject recovers easily from one session to another, the decision should be made to increase the load, together with the introduction of some variability, apart from the increase in volume and intensity: training frequency, some different exercise…, but if, on the contrary, they are noticeable symptoms of fatigue, the load should be reduced.

If the load moves at a lower speed than expected

If, finally, the speed were lower than expected, an analysis of the possible causes would have to be carried out similar to that of the previous case. With non-training issues ruled out, it is unlikely that the reason for reduced performance is that the workload is low, so one should try to suspend the training session, or lower the absolute intensity to equal the expected relative intensity, or even lower it enough to get the speed above the programmed speed, and even take a rest or a few recovery sessions and increase the load again later.

What is indicated in the previous paragraphs is a great contribution of the measurement of speed: the coach knows the applied load and the effects that it produces permanently and immediately. It is the maximum and best information that a coach can aspire to in order to make informed decisions and improve his training methodology.

You have at your disposal, in each session, precise information on the training carried out and on the physical condition of the athlete or the person trained. This is what you need to make decisions that allow you to improve your own training as a coach and the performance of the people you train, of course, if you make the right decisions. But you will always have the information you really need to decide how to act.

The end result will depend on the technician’s ability to use that information.

The speed of the first repetition

Until now there has always been talk of the speed of the first repetition of the first series, which will indicate the relative intensity that represents the absolute load with which you train, but we have not said anything about how to manage this speed in the successive ones with the same exercise and absolute load.

In this sense, it should be considered that if more than one series is done, the absolute load will not change, even if the speed of the first repetition in successive series drops slightly. In addition, in each series the same loss of speed established for that session will continue to be applied, although, naturally, taking the speed of the first repetition of each series as a reference.

Therefore, what constitutes a training session is:

1. an initial speed of the first repetition of the first set,
2. The maximum speed possible in the successive series and,
3. a loss of speed in the stable series during the total of the series performed.

This means that the speed of the first repetition of each of the successive series should be the maximum possible, and the absolute load will not be modified if there is a slight loss of speed with respect to that of the first series.

It would not make sense or practical feasibility to try to adjust the loads further for several reasons:

• First of all, because the losses are very small between the first repetitions of each series (it can be reduced or adjusted if desired by slightly increasing the recovery times between series). These losses are greater the greater the speed loss programmed for the first series, that is, the closer we get to the maximum number of repetitions possible in the series. But this is something that is part of the characteristics of the training itself.
• Secondly, because it is not feasible, without interfering in the training itself, to re-measure and make load changes in each series, because this would add significantly to the training load itself (greater number of repetitions and series than scheduled).
• Thirdly, because fatigue is part of the training and determines the degree of effort, and this would be uncontrollable if the absolute load is constantly changing. If we were to make these adjustments on each set in order to train each set at the same initial speed (same relative intensity), we would also need to do it on each rep of a set, because it is clear that as we do reps on each set, the relative intensity (the degree of effort) that each repetition represents is different, since the speed decreases progressively.

None of these changes seems recommendable and all are far from viable.

Repetitions per set are not scheduled

It has already been discussed on a few occasions, but it is necessary to indicate it at this time. In training organized through speed, a determined number of repetitions in the series is not programmed, but rather a loss of speed in the series given the load or relative intensity selected.

Carrying out speed-based training and programming the number of repetitions in the series is a contradiction and indicates little or no knowledge of the meaning of the already-hyped “speed-based training”. This means that not all the subjects will perform the same number of repetitions, the same volume, but the same degree of effort, which is what has been programmed and what, as it is reasonable to accept, determines the effect of the training.

On the contrary, if the same number of repetitions is programmed for the same relative intensity, the degree of effort will be different between the subjects.

Pre-training assessment

The evaluation prior to the start of a training cycle is carried out through a test with progressive loads.

What must be measured is the average propulsive velocity with which the subjects move each load. The maximum load reached in the test is a relative load (determined by speed) equal to or slightly higher than the maximum to be used in training. It will never be necessary to measure the MRI.

The evaluation after the training is carried out by analyzing the changes in the average propulsive velocity before the same absolute loads as in the initial test. If the speed with the maximum absolute load in the final test is clearly higher than that obtained in the initial test, an extra absolute load can be measured that could serve as a reference for the following training cycle. But this extra load would never be included in the evaluation of the evaluated training cycle, because it is not a load common to the two tests.

In this article, a review will be made about the loss of speed and percentage of repetitions performed and how these parameters affect the character of the effort and the degree of fatigue regardless of the total number of repetitions performed in the series.

In an attempt to move towards a further development of the applications of speed control in strength training, it is worth asking the following: What is the relationship between 1) the speed of the first repetition, 2) the loss of speed in the series and 3) the percentage of repetitions performed in the series before a certain loss of speed? An adequate answer to this question can provide very relevant information to improve dosage and training control.

In this series of articles we deal with some of the most important concepts of strength training, collecting notes from the recently published book Strength, Speed and Physical and Sports Performance written by renowned researchers Juan José González Badillo and Juan Ribas Serna.

To the first two questions, the speed of the first repetition and the loss of speed in the series, we now add another concept, the percentage of repetitions performed in the series before a certain loss of speed. The reason why this new problem is addressed is because it has always been observed that not all subjects perform the same number of repetitions with the same ease at the same relative intensity, that is, at the same speed in the first repetition.

Once the intensity or relative load has been determined, whether it is expressed through inappropriate indicators, such as the percentage of 1RM or an XRM or nRM, or by the speed of the first repetition of a series, the training volume must be decided, of which the number of repetitions performed in the series is a decisive part. To decide on this component of the global training load, two criteria are followed: either do all the possible repetitions in the series, which, as is recognizable in all the literature, is usually the most frequent and almost the only alternative for many specialists, or fail to do all the possible repetitions in the series.

About the drawbacks of getting to do all the possible repetitions in the series has already been discussed previously.. Of all of them, the inconvenience that must be addressed in this case is related to the probable fact that being able to do the same maximum number of repetitions in a series before a determined absolute load (individual loads for each subject) does not mean that you are training with the same percentage of RM, since it has already been observed that there is variability between individuals in the number of repetitions that can be performed in a series before the same relative intensity (Richens & Cleather, 2014; Sakamoto & Sinclair, 2006; Shimano et al., 2006; Terzis, Spengos, Manta, Sarris, & Georgiadis, 2008).

Therefore, the hypothesis is that if several subjects have been able to perform, for example, 10 repetitions before certain absolute loads, a part of them will be training with a load close to 75% of 1RM, because the average number of repetitions that can be done with this percentage is ~10 repetitions, but there will be subjects who are training with 80%, because they are clearly capable of doing more repetitions per series than the average with any load, and others who are working with 7 0%, for the opposite reason.

doing the same maximum number of repetitions in a series before a certain absolute load (individual loads for each subject) does not mean that you are training with the same percentage of the RM

To try to analyze to what extent the subjects differ from each other when doing the maximum possible number of repetitions before the same relative load, determined in this case by the speed of the first repetition in the series, a study was carried out (González-Badillo et al., 2017) in which a group of 27 subjects performed, with intervals of 4 to 7 days, the maximum number of repetitions possible with loads equivalent to 50, 55, 60, 6 5, 70, 75, 80 and 85% of the RM. These percentages were determined each day based on the speed with which the absolute loads were moved in the first repetition.

Tabla 1. Descriptive variables related to performing the maximum number of repetitions possible in the series with different relative intensities. (González-Badillo et al., 2017).

• Data are expressed as mean ± SD and (range)
• Repetitions: number of repetitions performed in the series; VMPmax: maximum average propulsive speed in the series; Final VMP: average propulsive velocity in the last repetition of the series.
• Diferencias significativas con respecto al: ͣ60% 1RM, ^b 65% 1RM; ^C 70% 1RM; ^d 75% 1RM; ^e 80% 1RM; ^f 85% 1RM.
• Table 1 shows the results corresponding to the bench press exercise.
• In the first column the percentages and the speeds corresponding to said percentages in the first repetition are indicated.
• The second column indicates the actual average speed at which the loads indicated in the first column were made and the range around the average. It can be seen that the average coincides with the target speed and that the maximum deviation in any subject was ±0.02 m·s^–¹ in any of the loads. This represents the maximum adjustment that can be required in any study or in training practice, since it cannot be expected that in all subjects the speed coincides exactly with the predicted speed. This small margin is tolerable and realistic to carry out any study or to carry out training.

The third column has an important informative value, because it indicates the average speed of the last repetition with each load. It can be seen that in all loads the final speed is practically the same. This speed, as we have always maintained, must coincide with the speed of the RM, because the last possible repetition in a series is precisely the last because it is done at the speed of the RM.

In this case, this speed is even slightly below the average speed of the MRI of this exercise, which, as we have seen in the previous chapter, is 0.16-0.18 m·s-¹. Naturally, there is also a small range of speeds around the average. The importance of this variable lies in the fact that if the last repetition had not been performed at the speed typical of the MRI, the test would not be valid, since this would be proof that the subjects had not performed the maximum possible number of repetitions in their tests.

The loss of speed in the series, shown in a fourth column, decreases as the relative intensity increases, since each time you start from a lower speed and always reach the same final speed. It is not relevant information, but it can serve as a reference to differentiate the intensities in relation to the maximum loss of speed that can be experienced with them.

The fifth column shows the repetitions performed with each percentage. The average values ​​inform us of the approximate number of repetitions that can be done with certain intensities, but with the particularity that in this case we can have high confidence that the intensities with which the tests have been done adjust with high precision to the actual intensities under analysis.

there is a wide range of repetitions achievable by different subjects at the same relative intensity

But the most relevant information in this column is that there is a wide range of repetitions that can be performed by different subjects at the same relative intensity. The average coefficient of variation is approximately 20% and there is a subject that doubles the number of repetitions that another can do at all intensities. If we take into account the standard deviations, we find that, for example, in the smallest load, 50% of the RM, 68% of the subjects would be in repetition values ​​between 19.9 and 31.5 repetitions, a percentage difference of 58% between the maximum and minimum value. And at the highest load, 85% RM, 68% of the subjects would be between 3.7 and 6.1 repetitions, a 65% percentage difference between the maximum and minimum value. Two important practical applications can be deduced from the results of this study.

The first is that, if the maximum possible number of repetitions is programmed for all the subjects, most of them would train with intensities (RM percentages) different from the others, given the variability that exists in the maximum number of repetitions that can be done at the same relative intensity.

Secondly, if we consider the case in which the maximum possible number of repetitions in the series is not programmed, the usual thing is to program the same number of repetitions for all the subjects with the same percentage of the RM. This way of determining the load has fewer drawbacks than most, but still has the same problem related to the discrepancy between the degree of effort programmed and the actual effort that represents the same number of repetitions for each subject.

This is so because even assuming that the first repetition of the series was done with the same relative intensity, doing the same number of repetitions with said intensity does not mean that all the subjects are making the same degree of effort: same loss of speed in the series. This is justified with the same argument previously exposed: the variability in the number of repetitions possible with the same relative intensity.

Indeed, given that not all subjects can perform the same repetitions at the same relative load, if a non-maximum number of repetitions is performed in the series, but common to all subjects, each subject will have done a different percentage of the total number of repetitions possible for him. This means that, having trained with the same relative intensity and number of repetitions in the series, the degree of fatigue, the loss of speed in the series, the degree of effort or character of the effort could have been different in each case.

This situation, which seems to lead us to a “dead end”, can be addressed and solved if we manage speed properly. If we start from the same speed before the first repetition of a series, that is, from the same relative intensity, it is reasonable to think that the degree of effort that the first repetition means is the same or extremely similar for all subjects (González-Badillo & Sánchez-Medina, 2010). Therefore, what we have left to solve is the degree of fatigue or effort that is added to the effort that the first repetition has represented. Naturally, this added effort will be determined by the number of repetitions done in the series, or more precisely, by the loss of speed in the series.

So, if we take into account that the degree of effort or fatigue generated in the series has a high relationship with the loss of speed in the series (Sánchez-Medina and González-Badillo, 2011), what we should control would be precisely this loss of speed. Indeed, given that fatigue can be estimated and controlled through the loss of speed (Edman, 1992; Allen, Lamb, & Westerblad, 2008; Sánchez-Medina & González-Badillo, 2011), it is reasonable to assume that in the event of the same loss of speed in the series, the degree of fatigue, effort or the nature of the effort will be very similar.

Once all of the above is accepted and the hypothesis formulated, what remains to be confirmed is whether, indeed, in the face of the same loss of speed, the nature of the effort is similar, that is, if in the face of the same loss of speed in the series, the relationship between the repetitions that are done and those that can be done in the series is the same or very similar in all cases.

If this is the case, it can be assumed that the degree of effort made is very similar for all subjects who have trained with the same relative intensity (same speed in the first repetition of the series) and have lost the same speed in the series, even though the number of repetitions performed has not been the same for all. Indeed, in the study that we have been commenting on (González-Badillo et al, 2017) it has been verified that when a certain percentage of execution speed is lost in the series, the same percentage of possible repetitions in the series has been performed regardless of the number of repetitions that can be done in the series itself.

It has been verified that when a certain percentage of execution speed is lost in the series, the same percentage of the possible repetitions in the series has been performed, regardless of the number of repetitions that can be done in the series itself.

Tabla 2. Percentage of repetitions performed with respect to the total number of possible repetitions in the series before different percentages of loss of speed in relative intensities between 50 and 70% of the RM (González-Badillo et al., 2017)

VMP: mean propulsive velocity; CV: Coefficient of variation.

Table 2 shows the data related to intensities between 50 and 70% of the MR. In this range of intensities, it can be seen that when faced with the same loss of speed in the series, the subjects tend to perform the same percentage of the total number of repetitions possible in the series at all intensities. For example, with a loss of 15% of the speed of the first repetition, at all these intensities practically the same percentage of possible repetitions has been performed, with an average of 31.2%.

Confidence in this data is based on the low coefficient of variation that accompanies it, of only 2.7%, which is also the highest of all the coefficients. If the standard deviation is taken as a reference, 68% of the subjects would be between 30.4 and 32% of repetitions performed with respect to the total possible, an extremely narrow range. Furthermore, it can be seen that the coefficient of variation decreases as the speed loss increases. This indicates that the greater the loss of speed in the series, the more similar is in all the subjects the percentage of repetitions performed before the same loss of speed in the series with all the relative intensities from 50 to 70% real of the RM.

Therefore, given the same relative intensity between 50 and 70% of the RM, if the same loss of speed occurs in the series, we can consider that the degree of effort will be similar, even though each subject has performed a different number of repetitions.

At intensities of 75, 80, and 85% of the RM, the percentage of repetitions performed at the same loss of speed is 2.5, 5, and 10% higher than that performed with intensities between 50 and 70%, respectively. For example, for the same percentage of repetitions performed, when at intensities between 50 and 70%, 10% with 80% and 5% with 85%. The speed losses for the same percentage of repetitions performed are in figure 1.

Figure 1. Losses of speed in the series with relative intensities from 50 to 85% of the RM (the 4 “X” axes) for the same percentage of repetitions performed (“Y” axis) (González-Badillo et al., 2017)

These differences are easily understandable, since as the number of repetitions possible in the series is reduced, each repetition represents a greater percentage of the total number of repetitions that can be performed. However, this natural tendency only starts to manifest itself after you can do ~10 reps in the set (~75% of 1RM). If the number of repetitions possible is greater, as occurs from 50 to 70% of the RM, the number of repetitions possible in the series does not even influence the common percentage of repetitions performed between different intensities before the same loss of speed.

The data that we have provided in relation to the bench press exercise has also been studied in the full squat exercise (Rodríguez-Rossell et al., 2019). Table 16.3 presents the results of the study in the squat with the four relative intensities that were directly analyzed: 50, 60, 70 and 80% of the RM.

Tabla 3. Characteristics of the bench press and squat efforts with loads of 50, 60, 70 and 80% of 1RM: basic similarities and differences (Rodríguez-Rosell et al., 2019).

In the squat exercise in Table 3, it can be seen that the measurements of the speed of the first repetition coincide with the speed of the percentages that are analyzed. It can also be seen that the last repetition of the series with each intensity is typical of RM, and even somewhat below average, which indicates that the subjects really performed the maximum number of repetitions possible.

The number of repetitions performed in the squat exercise for the same relative intensity is slightly lower than in the bench press, between 2 and 3 repetitions less. The coefficient of variation in the number of repetitions is somewhat higher than in the bench press, with an approximate average of 30%.

Given the characteristics of the squat exercise in terms of the degree of demand or effort required to perform series until exhaustion, in this exercise only the four indicated relative intensities were measured. Taking these four intensities and the corresponding number of repetitions performed with each of them as a reference, we have calculated the number of repetitions that could be done with a greater range of relative intensities. The fit of the four relative intensities and the repetitions performed with them was almost perfect: R² = 0.9996. This adjustment is presented in Figure 2.

Based on the regression equation corresponding to the relationship between these two variables, we have estimated the repetitions with other intensity values. Table 4 presents these data. The first column indicates the percentages of the RM, in the second the estimation of the number of repetitions performed with each percentage of the RM and in the third the number of repetitions measured directly with the percentages of 50, 60, 70 and 80% of the RM.

It can be seen in this table that the differences between the number of repetitions measured and the one estimated with these intensities are practically nil. Then the estimated replicate values ​​can be considered. Very adjusted to the real mean of repetitions that a population of young subjects familiar with strength training would do, with a mean of 115 kg RM for 76 kg of mean body weight, and with a range from 91 to 153 kg of RM value. Therefore, these results would be applicable to a wide population.

Figure 2. Relationship between the relative intensities of 50, 60, 70 and 80% of the RM and the number of repetitions performed with each of them in the squat exercise (Graphic prepared with data extracted from Rodríguez-Rosell et al., 2019).

Tabla 4. Estimated repetitions with intensities between 40 and 90% of the RM and repetitions measured directly with the intensities of 50, 60, 70 and 80% of the RM in the squat exercise.

Following the same reasoning exposed for the bench press, once the speed with which each percentage of the RM is moved in the squat and the number of repetitions that can be performed with each percentage in this exercise is known, what remains to be solved is the degree of fatigue or effort that is added to the effort represented by the first repetition in the series.

Naturally, this added effort will be determined by the number of repetitions done in the series, but, as we can see in Table 3, as in the bench press, the maximum number of repetitions to exhaustion can vary greatly between subjects, so we will have to resort to the loss of speed in the series to try to equalize the efforts or fatigue, ruling out the number of repetitions to be carried out in the series as a priority reference in programming.

Therefore, from a practical point of view, we would have to establish what percentage of the total repetitions has been performed when a certain speed has been lost in the series. In the study that is being discussed (Rodríguez-Roseel et al., 2019) this data has also been verified when a certain percentage of the speed of execution is lost in the series with the intensities of 50, 60, 70 and 80% of the RM. Table 5 shows the results.

Table 5. Percentage of repetitions performed before a certain loss of speed in the series in relation to the maximum possible repetitions in the series until exhaustion in the bench press and squat exercises with the indicated RM percentages (Rodríguez-Rosell et al., 2019).

*1RM = 1 repetition máximum; BP = bench press; SQ = full squat.

• Data are mean ± SD.
• Statistically significant differences with respect to: 50% 1RM.
• Statisticaly significant differences with respect to: 60% 1RM.
• Statisticaly significant differences with respect to: 70% 1RM.
• BP exercise.

In the first column of table 16.5 we have the loss of speed in the series and in the rest the percentage of repetitions performed before each loss of speed with the different relative intensities in each exercise. It can be observed that the percentage of repetitions performed before the same loss of speed in the series is always higher in the squat (SQ) than in the bench press (BP), and the difference tends to increase the higher the intensity.

In addition, while in the bench press the percentage of repetitions performed for the same loss of speed remains practically stable up to 70% of the RM, as we have already seen when analyzing this exercise in previous paragraphs, in the squat only stability is maintained. with 50 and 60%, increasing the percentage of repetitions performed for the same loss of speed with 70% and even more with 80%.

The circumstance occurs that the increases in the percentage performed before the same loss of speed begin in both exercises when with the corresponding intensity it is possible to do an average of ~10 maximum repetitions, which corresponds to 70% in the squat and 75% in the bench press. It seems, therefore, that the influence of the possible number of repetitions in the series on the percentage of repetitions performed for the same loss of speed in the series is maintained in the squat. (Note: naturally, in Table 5, the value of speed loss of 65% with the relative load of 80% should be discarded, which is a mistake, since it would exceed 100% of the repeats that can be carried out).

Unfortunately, the information on the squat exercise is somewhat scarcer than the bench press, as only four percentages of the RM could be analyzed, but it allows for very useful applications.

On the one hand, based on the data obtained, the values ​​corresponding to 55% of the RM can be estimated, since, if the values ​​of the percentages of repetitions performed are the same with 50 and 60%, it is reasonable to accept that the values ​​corresponding to 55% would also be equal to both. This is logical, but it is also reinforced by the results obtained in the bench press: the intermediate values ​​(55, 60 and 65%) between 50 and 70% are equal to those of these two extreme values, which are also equal to each other. In addition, an estimate of the corresponding 75% values ​​could also be made, which must be of an intermediate value between 70 and 80%, in the same way that it occurred in the bench press between 75, 80 and 85%.

But perhaps the most useful thing is to check that when 20% of the speed has been lost in the squat exercise, we are slightly below half of the possible repetitions in the series with all percentages of the RM except 80% where we are practically half. If it is taken into account that in the investigations carried out to date (Pareja-Blanco et al., 2017; Rodríguez-Rosell, Doctoral Thesis) in which the loss of speed in the series has been taken as a reference to control the training dosage, it is observed that exceeding a loss of 20% of the loss of speed in this exercise already begins to cause a decrease in the training effect, being able to control losses of 10, 15 and 20%, even 25%, allows the control of most or all of the training that an athlete must do in his sporting life.

In addition, we can also remember those other studies, although somewhat less controlled, in which doing half of the possible repetitions offered a better result than reaching muscular failure (maximum loss of speed in the series) (Izquierdo-Gabarren et al., 2010 )

This practical application, naturally, translates into the possibility of being able to tell the athlete to perform the movement at the maximum possible speed until losing 10, 15 or 20% of the speed of the first repetition, without indicating the number of repetitions. what it has to do.

This would make it possible to equalize the effort (the degree of fatigue) that we are asking of all the athletes, which could not be done by prescribing an equal number of repetitions to all the subjects.

En relación con el grado de esfuerzo o fatiga, en este estudio se confirmo la alta relación entre la pérdida de velocidad en la serie y la fatiga, determinada por la pérdida de velocidad pre-post esfuerzo con la carga que se podía desplazar a 1 m·s^–¹. A relationship was found between these two variables of r = 0.97 in the bench press and r = 0.99 in the squat. It must be taken into account that, as can be seen in table 16.3, the range of repetitions with the percentages analyzed was wide, so this relationship occurred independently of the number of repetitions performed by each subject.

One question that we ask ourselves is whether the relationship of these tests with the maximum possible number of repetitions in the series was reliable or not. To verify this, we did a repetition of the test one week apart with a load of 60% of the RM. Table 16.6 shows the results of both tests.

VMP: mean propulsive velocity.

Tabla 6. Data on performing a test to exhaustion on two occasions with a load equivalent to 60% of the MRI (Data taken from Rodríguez-Rosell’s doctoral thesis).

It can be seen that all the data are practically the same in both tests, which confirms the stability of carrying out tests with these characteristics. Special attention should be paid to the column of the last repetition of the series, which is repeated almost exactly, with the same average speed and range of speeds, as well as the column of repetitions performed, with the same number and range of repetitions, which It confirms, on the one hand, the stability in the number of repetitions that a person can do at a given relative intensity, and on the other, the stability in the variability between subjects in the number of repetitions that can be performed at the same initial speed.

In addition, the percentages of repetitions performed before different speed losses in the series were practically the same in both tests (table 7).

Tabla 7. Percentages of repetitions performed for different speed losses in the series in two tests with 60% of the RM (Data taken from Rodríguez-Rosell’s doctoral thesis).

Another issue that caused concern was whether, having reached the same loss of speed in the series, the subjects who tended to do more repetitions in the series had experienced more fatigue than those who did less. To do this, the subjects were divided into two halves, one made up of the subjects who had done more repetitions (high repetitions group: GAR) and the other by those who had done less (low repetitions GBR group). Table 16.8 presents the results of the grouping of the subjects and the average number of repetitions performed with each percentage of the RM. It can be seen that the GAR performed an average of 32% more repetitions than the GBR in the bench press and 59% more in the squat, giving rise to statistically significant differences between both groups in all relative intensities.

Do the subjects who do more repetitions in the series fatigue more in the face of the same loss of speed and relative intensity?

Tabla 8. Distribution of the subjects in two groups based on the repetitions performed before each percentage of the RM in the bench press and squat exercises (Rodríguez-Rosell et al., 2019).

• GBR: half of the subjects who performed the lowest number of repetitions per series
• GAR: half of the subjects who performed the highest number of repetitions per series
• PB: Bench press; Squat: Full squat;
• Differences between groups: *** p ˂ 0.001

Once the subjects were grouped, it was verified what the speed loss had been with the load that, prior to the tests, could be moved at 1 m·s^–¹. This loss of speed is the variable that would serve as an indicator of the degree of fatigue reached by each subject. The results are presented in Figure 16.3.

No significant differences were observed between the groups. This analysis, really compromised for the authors of the study, confirmed the importance of controlling the loss of speed in the series as an indicator of the degree of fatigue generated in the series or set of series of a training session, despite the fact that the number of repetitions performed by each subject was different, as well as the use of the load that can be moved at 1 m s^-¹ as a criterion to assess and validate the degree of fatigue generated by training.

If what is programmed for each training session is a certain degree of effort or fatigue, and this seems hardly debatable, the probably most reasonable and precise way of knowing the degree of effort that is programmed and performed is by controlling the loss of speed in the series at a certain speed of the first repetition in the series itself. Knowing that, in turn, this speed is the best indicator of what is the relative intensity or real percentage of the RM with which the training of an exercise begins.

The probably most reasonable and precise way of knowing the degree of effort that is programmed and performed is by controlling the loss of speed in the series at a certain speed of the first repetition in the series itself.

Figure 13. Loss of VMP with the load 1 m s^–¹ after each of the tests of the maximum number of repetitions possible in each of the groups in fusion of the number of repetitions performed (GBR vs GAR) for the exercise bench press (A) and full squat (B) (Rodríguez-Rosell et al., 2019).

Therefore, if we know the speed of the first repetition, we know the relative intensity (percentage of the RM) (González-Badillo & Sánchez-Medina, 2010), and therefore the degree of effort that said first repetition represents. In addition, if we measure the loss of speed during the series, we will have the degree of fatigue that has been generated in the series (Sánchez-Medina & González-Badillo, 2011; Rodríguez-Rosell et al., 2019).

And since given the same percentage of loss of speed in the series, the percentage of repetitions performed is the same or very similar for all subjects, regardless of the relative intensity and the number of repetitions that can be done in the series (González-Badillo et al., 2017; Rodríguez-Rosell et al., 2019), if we control the speed of the first repetition and the loss of speed in the series, we will have very precise information on the degree of fatigue (character of the effort, degree of of effort) that has been generated to the subject and, in addition, that this degree of fatigue is very similar for all the subjects with the same relative intensity and the same loss of speed in the series. That is, it is the loss of velocity in the set that equals the effort, not the number of repetitions performed in the set at the same relative intensity.

If we control the speed of the first repetition and the loss of speed in the series, we will have very precise information on the degree of fatigue (character of the effort).

Therefore, the control of the training load, quantified through the degree of effort or character of the effort made, is achieved in the most precise way if we control the speed of the first repetition in the series and the loss of speed in the series. .

From the above, the following can be concluded:

• Being able to do the same number of repetitions in a series before a determined absolute load (individual load for each subject) does not mean that you are training with the same percentage of the RM. Therefore, performing the same number of repetitions at the same relative load means that most athletes make a different effort than others. This is because the number of repetitions performed by each subject at the same relative intensity is quite different.
• If the same loss of speed in the series is taken as a reference before the same relative load (mass), the efforts made will be very similar, although the number of repetitions carried out in each series is different for each subject.
• If a non-maximum number of repetitions is performed in the series, but common to all the subjects, each subject will have done a different percentage of the total number of repetitions possible for him. This means that, having trained with the same relative intensity and the same number of repetitions in the series, the degree of fatigue, degree of effort or character of the effort could have been different in each case.
• Given the same loss of speed in the series, the relationship between the repetitions that are done and those that can be done in the series is the same or very similar for all subjects.
• When a certain percentage of the speed of execution in the series is lost, the same percentage of the possible repetitions in the series has been performed at intensities between 50 and 70% of the RM in the bench press. If the intensities are 75, 80 and 85%, given the same percentage of repetitions performed, the speed losses will be 2.5, 5 and 10% less, respectively. If it is the squat exercise, given the same percentage of speed loss in the series, from 50 to 60% and probably 65%, the percentage of repetitions performed is the same, and increases from 70% of the RM. It seems that the increase in the percentage of repetitions performed for the same loss of speed in the series occurs when the number of repetitions possible in the series is approximately 10.
• If we control the speed of the first repetition and the loss of speed in the series, we will have very precise information on the degree of fatigue (character of the effort). that has been generated to the subject and, furthermore, that this degree of fatigue is very similar for everyone with the same relative intensity and the same loss of speed in the series. That is, it is the loss of velocity in the set that equalizes the effort, not the number of repetitions performed in the set with the same relative load.
• Therefore, the loss of speed in the series equalizes the efforts, the degree of fatigue generated, even if two people have done a different number of repetitions before the same relative load:
  • This means that what would best express the degree of effort, and what should be programmed, is the speed of the first repetition and the loss of speed in the series, not the number of repetitions to perform in the series under a load (relative to or absolute)
  • If speed can be measured, repeats should never be programmed into the set.

WHAT TO DO WHEN YOU CANNOT ALWAYS MEASURE SPEED

One of the immediate concerns for anyone who reads or hears about the benefits of speed control is the impossibility of measuring it. The solution, naturally, is to find a measurement system that allows this information to be obtained permanently, but if this cannot be achieved, we can offer an alternative that, in part, solves the problem of knowing if a subject can be located in the average in relation to the maximum number of repetitions you can do at a certain relative intensity or if it is above or below. For this, it would be necessary to be able to measure speed at least once in sporting life. The procedure would be the following:

• If speed can be measured on one occasion, it is possible to estimate in a very approximate way the number of repetitions in the series that a subject can do at a given relative load without reaching muscular failure (XRM or nRM).
• First, the speed of the first repetition would be taken as a reference. This would indicate the relative intensity with which the test is to be carried out.
• The exercise would then be performed at the maximum speed possible in each repetition until approximately 40-50% of the speed of the first repetition was lost. If it is about the bench press, you can reach 50%, if it is about the squat it is more than enough to reach 40%.
• The evolution of the number of repetitions performed before 2-3 percentages of speed loss in the series is analyzed. For example, 15, 20, 25, 30%…
• The necessary calculation is made to estimate the number of possible repetitions in the series based on the number of repetitions performed with each percentage of speed loss. For this, the tables that we have exposed in this article are consulted.
• The results obtained with each percentage of speed loss are contrasted, and it is verified if in all cases the result is very similar. It should be, unless the subject did not perform the test correctly.
• Once the result is obtained, we will proceed to verify where the subject is located. To do this, five groups could be made: those who are within the measure, those who are 10-15% above or below the measure, and those who are 25-30% or more above or below the measure. half.
• Once the subjects have been located, the number of repetitions programmed at a relative intensity (assumed to be at least close to what it is intended to be) will be different for each one depending on their location within the groups to which they belong.
• Once the subject is located, it is very likely that this will not change throughout his sporting life, so it is information obtained in one day that is useful for a lifetime.
• All this procedure could be done with more than one intensity, at least two, on different days, for example, with 50 and 70% or 60% and 80%. This would help confirm the results. The two tests could be done in a week, 3-4 days apart.

The following article introduces the concept of the Effort Index and its relationship with the loss of speed in the series and the character of the effort.

In this series of articles we deal with some of the most important concepts of strength training, collecting notes from the recently published book Strength, Speed ​​and Physical and Sports Performance written by renowned researchers Juan José González Badillo and Juan Ribas Serna.

SUMMARY

• Given the same relative intensity and the same loss of speed in the series, fatigue is also similar, although the number of repetitions performed in the series by each subject is different.
• The effort index is the result of multiplying the velocity of each percentage of the RM by the value of the loss of velocity in the series or set of series.
• The effort index has a much higher predictive value than any other variable to estimate the loss of speed with a load of 1 m·s^-¹, that is, to estimate the degree of effort.
• Only if the effort rates are equalized can it be ensured that the relative intensity is the independent variable of the training.
• Average ranges of the Effort index between 7.5 and 14.8 for the squat exercise with an intensity of 70 to 85% offer better results than values ​​higher than 22.1.

On the one hand, it has been observed that when training with loads with which a maximum number of repetitions in the series can be done between ~12 and ~4, and efforts are made that go from 50% of the possible repetitions to the maximum possible repetitions (XRM or nRM), there is a close relationship between the loss of speed in the series and the fatigue generated. Fatigue was estimated by the loss of speed before a load that could be moved at 1 m*s-1 and by the loss of jump height.

The relationship between these variables when dealing individually with each of the loads studied is almost perfect. But, in addition, in this case, when they were all considered together, the ratios were also very high. That means that when it comes to determining the intensity through the maximum number of repetitions possible in the series (between 12 and 4 repetitions maximum, in this case), lthe loss of speed in the series, or the number of repetitions performed in the set, remarkably accurately estimates the fatigue generated in the set.

However, in this case, two issues should be taken into account:

i) when training with these loads, not all subjects did so with the same relative intensity, since, as has been seen, performing the same maximum repetitions in the series does not represent the same relative intensity for all subjects, and

ii) A certain number of repetitions were performed with respect to the maximum possible, starting with at least half of the possible repetitions, so we do not know what happens when less than half of the possible repetitions are done in the series, load, which seems to be very important in training.

Therefore, the relative intensity was not the same for all subjects, the loss of speed in the series was not determined before the effort was made, but was measured afterwards, the efforts were always made with at least half of the possible repetitions in the series.

On the other hand, when starting from the same relative intensity, it has been verified that with the same loss of speed in the series, the percentage of repetitions performed in the series is similar, which allows us to admit that Faced with the same relative intensity and the same loss of speed in the series, fatigue is also similar, although the number of repetitions performed in the series by each subject is different..

Faced with the same relative intensity and the same loss of speed in the series, fatigue is also similar, although the number of repetitions performed in the series by each subject is different.

According to what has been exposed, given the same relative intensity, whether it is estimated by the maximum number of repetitions that can be done in a series, or by the speed of the first repetition in the series, the loss of speed in the series is a good estimator of the degree of effort made. However, we still do not have a solution to all possible situations that arise. On the one hand, because taking an XRM as a reference is not appropriate, for the multiple reasons that we have explained in chapter 4, and secondly because we have not contrasted the degree of effort generated at different relative intensities when these are determined by the speed of the first repetition.

In previous articles it has been shown that the definition and quantification of the character of the effort or degree of effort is expressed in the most complete and precise way by the value of the speed of the first repetition and by the value of the loss of speed in the series. If you start from the same speed in the first repetition, that is, from the same relative intensity, this variable is already controlled, so the only thing that remains to be checked is whether the loss of speed in the series correctly expresses the degree of effort. This has been amply verified through the studies commented in the previous sections. But it remains to be verified if, in fact, these two variables are valid when calculating the degree of effort generated with the combination of different relative intensities and different speed losses in the series.

the loss of speed in the series is a good estimator of the degree of effort expended

To address this problem, a study has been carried out, partially published (Rodríguez-Rosell et al., 2018), in which the loss of speed with a load of 1 m s has been analyzed.^–¹ (fatigue) and the jump loss (fatigue) produced in 16 efforts, consisting of four speed losses after three series with the maximum load of the day at four relative intensities. In the bench press the four speed losses with respect to the speed of the first repetition were: 15, 25, 40 and 55%, and in the squat: 10, 20, 30 and 45%. The four relative intensities for both exercises were: 50, 60, 70, and 80% of 1RM. Table 1 presents the scheme of the study.

squat

bench press

Tabla 1. Diagram of the efforts made with the squat and bench press exercises, with four relative intensities and four speed losses in each exercise (Rodríguez-Rosell et al., 2018).

Figure 1 shows an example of the protocol followed to carry out each of the efforts. In each session, during the warm-up phase, the load that the subject was capable of displacing at ~1 m s^-1 was measured.¹ (the three initial dark bars in the figure), the subject continued to warm up until reaching the load with which the expected effort for the session had to be made, performing the three series at the maximum speed possible to reach the expected loss of speed in each series (the three sets of lighter bars in the center of the image).

Immediately after doing the last repetition of the third series, the speed with the load that had previously moved ~1 m s^-¹ (dark bars on the right of the image) was measured again and a blood sample was taken. to measure lactate concentration. When it came to the squat exercise, before warming up with loads, a specific warm-up was done for the vertical jump and it was measured, and at the end of the last repetition of the training session it was measured again.

Figure 1. Real example of an effort protocol of a subject in the squat exercise with the load equivalent to 60% of the RM (0.98 ~1 m s^–¹ of speed in the first repetition of the first series) and a 30% loss of speed in each series. Recovery time between sets was 4 minutes. The average speed loss in the three series was 29.5%, and the speed loss with the 1 m·s^–¹ load after effort was 20.2%. The subject performed 7, 6 and 7 repetitions in the first, second and third series, respectively, until losing the programmed speed. (Rodríguez-Rosell et al., 2018).

Table 2 shows the speed losses with the load of 1 m·s^–¹ and the lactate concentration after the 16 efforts with each of the exercises. Within each exercise, there is a clear tendency to lose more speed (more fatigue) and to reach greater lactate contraction than more speed is lost in the series at the same relative intensity, but the values ​​of these two variables decrease as the relative intensity increases. Although the differences between the exercises in the variables of velocity loss and lactate concentration are indicated at the foot of the table, it must be taken into account that these data have been produced with different values ​​of velocity loss in the series in both exercises.

• SQ = ful back-quat exercise (n = 11); BP = bench press exercise (n = 10); REP = resistance exercise protocol; MPV = mean propulsive velocity; V1 m·s^–¹ = load that elicited
• MPV of ~1 m·s^–¹; RM = repetition maximum.
• Data are men ± SD Post-exercise lactate significantly different (P ˂ 0.001) from pre-exercise for all REPs.
• Significantly different than BP: p ˂ 0.001
• Significantly different than BP: p ˂ 0.01
• Significantly different than BP: p ˂ 0.05

Table 2. Loss of speed post effort with a load of 1 m s^–¹ (central column in each exercise) lactate concentration in the squat (SQ) and bench press (BP) exercises (Rodríguez-Rosell et al., 2018).

the fatigue generated by the training section tends to be greater with the same loss of speed in the series the lower the relative intensity

Therefore, as indicated and shown in table 2, the loss of speed with the load of 1 m s^–¹, as an indicator of the fatigue generated by the training section, tends to be greater with the same loss of speed in the series, the lower the relative intensity. When training with 50% of the RM in the bench press, 29.6% is lost for the four speed losses with which it was trained (15, 25, 40 and 55% of the speed of the first repetition), while with 60, 70 and 80%, 23.2, 20.6% and 17% were lost respectively. In the squat the losses were: 21.6, 18.7, 14.9 and 15% for 50, 60, 70 and 80%, respectively.

Attention should be paid to this detail, since there is a tendency to think that if the relative intensity is lower, the fatigue will also be less, which can lead to important errors: if the loss of speed is the same, the lower the relative intensity (at least from 50% of the RM, but it is very likely that it also occurs at lower intensities), the greater the fatigue. This, on the other hand, should not lead us to another probable error, such as thinking that then what you have to do is train with relatively high loads, which cause less fatigue, because this can also have important negative effects, since with high loads, the average speed of execution must necessarily be very low, which may not always have a positive effect on performance, but rather the opposite.

with high loads, the average execution speed must necessarily be very low, which may not always have a positive effect on performance, but rather the opposite.

Given that the lower the percentage with which you train, the more repetitions you can do until you lose a certain speed in the series, the loss of speed with the load of 1 m s^–¹ It depends on the repetitions that have been made in the series when the percentages oscillate between 50 and 80% of the RM and its values ​​have been estimated by the speed of the first repetition in the first series of the session.

In fact, the relationship between these variables is r = 0.94 (p˂0.001). But it is evident that the fatigue generated by the first repetition must also be included in the assessment of the character of the effort, since it is the first indicator of the degree of effort that a subject is going to make. This would lead us to try to find an index that would represent the degree of fatigue more accurately and with high validity.

This index should include the two variables that, as we have been proposing, can influence the fatigue generated: the speed of the first repetition (relative intensity) and the loss of speed in the series. Therefore, this index could be the result of multiplying the speed of the first repetition by the loss of speed in the session, which in this case consisted of three series.

Three sets at the maximum load for the session is a very common set number and is even considered to be within an effective set range for strength improvement (Rhea et al., 2002a; 2002b; 2003). This index is a way of presenting what has been proposed for years, the “character of effort” (CE), but each time more precisely defined. In this case, we could call this expression of the CE the Effort Index (IE), which is what it really represents, the degree of effort or degree of fatigue generated or caused to the person being trained.

Three series with the maximum load of the session is a very common series number and even considered as included within an effective range of series for the improvement of strength.

But, this IE needs to be validated by comparing its behavior and its values ​​with an indisputable and clearly valid indicator of the degree of fatigue generated, such as the loss of speed under the same absolute load, which in this case is the load that can be moved at ~1 m s.^–¹ before making the effort, as well as the loss of height of the vertical jump, which is equivalent to saying loss of speed in the jump, when it comes to exercises performed with the legs, and that we have been using since before the first contact platforms appeared in the 80s.

The values of this IE will be the result of multiplying the own speed of each percentage of the RM by the value of the loss of speed in the series or set of series. If, for example, the relative load (real percentage of the RM) with which you want to train has an average propulsive velocity of 1 m s^-¹ and the loss of velocity that you want is 15%, the value of the IE resulting will be 15 (1×15).

Of course, when put into practice, this IE will not always have an exact value of 15, as the speed of the first repetition and the loss of speed in the set are not likely to always match the programmed values, but in practice, the differences are very small, so its value is practically the same as what has been programmed.

And if this is so, its effect must also be the same. It would not make sense to think that if instead of 15, the resulting IE had a value of 14.5, the effect would be different, especially since on another day it could be 15.3. To consider that these small differences could have a significant effect on the training result would be to give too much importance and power to IE, more than it already has.

Naturally, for the same loss of velocity in the series, the IE values ​​are lower the higher the relative intensity, since the higher this is, the lower the velocity of the RM percentages. This should give rise, as has been shown in the results of the commented study, to that the speed losses with the load of 1 m s^–1¹ (fatigue) tend to be lower with higher intensities, which, in turn, validates IE itself, because it determines the degree of fatigue (loss of speed in the series) based on its value as a product of the variables that make it up, not just based on the value of one of them.

Tables 3 and 4 show the IE calculations for the bench press and squat exercises.

Tabla 3. IE in the Bench Press Exercise (Rounded Values)

Tabla 4. IE in the Squat Exercise (Rounded Values)

The data in tables 3 and 4 are rounded, and may differ slightly from those published in the 2017 book on speed (González-Badillo et al., 2017). This is due to the fact that in that document the values ​​of the IE were derived directly from the real data of the study, while in this case it is the calculation of each IE according to the own speed of the corresponding percentage and the expected loss of speed. The blank spaces in the tables are due to the fact that with the corresponding relative intensities a loss of speed as indicated cannot be produced.

0.14 and 0.27 m·s^–¹ have been considered as the minimum possible speed in the series until muscular failure for the bench press and the squat, respectively. These values ​​correspond to those obtained as a mean in the respective tests of the maximum possible number of repetitions in the series (tables 1 and 3).

Once these questions related to the concept of EI have been clarified, it is necessary to verify its validity as an indicator of the degree of effort or fatigue generated in training. For this, its relationship with the two reference criteria has been verified, the loss of speed with the load of 1 m·s^–¹ and the loss of vertical jump (CMJ). The relationship of the IE and the loss of speed with the load of 1 m s^–¹ was r = 0.98 (p ˂ 0.001) for the bench press and r = 0.091 (p ˂ 0.001) for the squat (figure 2).

Figure 2. Relationship between IE (degree of effort) and velocity loss with 1 m s^–¹ load in bench press (top figure and squat (bottom figure). TEE standard error of estimate. (Rodríguez-Roseel et al., 2018).

The Effort Index has a much higher predictive value than any other variable to estimate the loss of speed with a load of 1 m s^-¹, that is, to estimate the degree of effort, which is what is programmed when designing a workout.

Therefore, this IE has a much higher predictive value than any other variable to estimate the loss of speed with a load of 1 m s^–¹, that is, to estimate the degree of effort, which, as indicated, is what is programmed when designing a workout. If we quantify these relationships in terms of explained variance, we see that bench press IE explains 96% of the variance of velocity loss with the 1 m s-¹ load, virtually all of the variance, and squat IE 83%.

In other words, in both cases a very high percentage of the variance produced in the loss of speed with the load of 1 m·s^–¹ is explained. The slightly lower value given in the squat may explain the greater technical complexity of this exercise compared to the bench press. In addition, the IE presents a high correlation with the loss of CMJ (r = 0.93; p ˂ 0.001; it explains 86.5% of the variance of the loss of high, and with a very low standard error of estimation: 1.8).

Therefore, these correlation values ​​and their corresponding explained variance values ​​provide us with high confidence in the predictive power of the IE in both exercises, with the particularity that the squat can be assessed by two exercises or fatigue indicator criteria.

But, in addition to what is indicated, the IE generated in the squat offers the opportunity to apply it to other variables related to an exercise frequently used in the training of any athlete, such as sprinting. In the commented study, the degree of fatigue throughout the 20-m race was also assessed. This test was performed ~2 minutes after the end of the effort. The relationships between the IE and a series of variables were: with the increase of the time in 20 m, r = 0.77 (p ˂ 0.001), with the loss of maximum speed, r = 0.84 (p ˂ 0.001) and with the increase of the contact time in the race, r = 0.66 (p ˂ 0.01). As can be seen, the IE in the squat has an important application in the prediction of fatigue in different types of performance.

In this sense, the relationship observed in the IE in the full squat exercise and the reduction in performance in the 20-m race is pertinent and very relevant. Figure 3 shows the graphical presentation of this relationship.

In the graph it can be seen that for an IE of 10, the increase in time in the race is more than 3.5%. This is a very considerable acute negative effect. This is more relevant if we consider that the IE that causes this performance reduction is small. It is equivalent to performing 4-5 repetitions with a relative load of 60% of the RM. Which means that at 60% RM you should lose 10% of your speed for the first rep in the set.

As explained in the graph itself, with 60% you can do about 16 repetitions on average. A 10% loss of speed in the set means that 26.9% of the possible reps have been performed, and this is equivalent to doing 4-5 reps in the set. That is, this training, with three series, is a moderate-low training, which could be very positive for the improvement of performance for many athletes, but that has caused an acute negative effect on a 20 m race at ~2 minutes after doing the squat exercise.

It is natural, on the one hand, that if the interval time had been shorter, as is usual in some training practices, the negative effect would have been greater, and, on the other hand, that, according to the graph itself, with higher EI, the effects would tend to be even more negative.

Conclusion: the supposed “transfer” exercise, in addition to not being such, can be carried out in quite negative conditions.

Figure 3. Relationship between the IE and the change in time in a 20 m race performed ~2 minutes after performing the squat exercise (see text for further explanation) (Data taken from Rodríguez-Rosell’s doctoral thesis).

This sequence of exercises, but with less recovery time between them, is considered in some cases as a “transfer exercise” or executed in this way because in doing the second exercise “something is being transferred” to the second exercise. However, these results indicate that the supposed “transfer” exercise, in addition to not being such, is being carried out under quite unfavorable conditions, with each loss of performance.

It is logical to think that if 20-m runs are done, it is to be done at the subject’s maximum personal speed or close to it, or, in the worst case, with a minimum loss of speed, which would be enough to interrupt the training. However, with this sequence of exercise, so common, neither “transfers” nor trains in proper conditions, but rather the opposite.

In addition to the speed losses with the 1 m·s^-¹ load, the CMJ is also a reference criterion for the assessment of fatigue. This exercise is also very easy to perform, it does not interfere with training and does not cause fatigue, therefore, if the loss of height were related to other exercises and with the loss of speed itself with the load of 1 m s^–¹, could be a very useful exercise to assess the degree of fatigue reached in a training session easily, quickly and cheaply.

As expected, since the jump loss is a loss of speed, the loss of CMJ has a high relationship with the loss of speed with the load of 1 m s-¹, r = 0.96 (p ˂ 0.001), so in the squat exercise, to estimate the degree of fatigue, it would be equivalent to measure the loss of speed with the load of 1 m s^-¹ or jump loss. But, in addition, the loss of CMJ serves as a good predictor of the increase in time in 20 (r = 0.79; p ˂ 0.001) and in 5 m (r = 0.84; p ˂ 0.001), of the loss of speed in the race (r = 0.77; p ˂ 0.001) and of the increase in contact time (r = 0.77; p ˂ 0.00 1).

If we take the regression equations indicated in figure 16.5 for the bench press and the squat, as well as the one associated with the CMJ in its relationship with the IE (y = 0.3306x + 9.3785), we can have a fairly approximate estimate of the loss of velocity with the 1 m s load.^-¹ and of the CMJ before different values of EI (table 16.13).

With these data and those that have been commented on the variables that make up the EI, a wide field of research opens up. The first thing would be to determine the effect of the different IE values ​​(Table 3). With these data and those that we have commented on the variables that make up the IE, a wide field of research opens up. The first thing would be to determine the effect of the different IE values, that is, of the different degrees of effort. There is still not enough data on this, although some guidelines will be given later that can serve as a reference to improve knowledge about the load-effect relationship of training.

Tabla 3. Estimated values ​​of velocity loss with the 1 m·s-¹ load and with the CMJ with a range of IE from 6 to 40.

In addition to what is indicated, the IE, the loss of speed with the load of 1 m·s^-¹ and the CMJ present a high predictive validity of metabolic stress, estimated through the lactate concentration after the effort.

The IE, the loss of speed with the load of 1 m s^-¹ and the CMJ have a high predictive validity of metabolic stress

In the commented study, the lactate concentration presented significant positive relationships with the IE in the bench press (r = 0.95; p ˂ 0.001) and the squat (r = 0.9; p ˂ 0.001), with the loss of speed with the load of 1 m s^–¹ in the bench press (r = 0.95; p ˂ 0.001) and the squat (r = 0.95; 0.001) and with the jump loss (r = 0.98; p ˂ 0.001). As can be deduced from these results, knowing the speed loss with the load of 1 m s^-1¹ and the loss of jump height, a very precise estimate of the lactate concentration can be made, or even better, if the values ​​of these two variables are known, it is not necessary to do any post-exercise lactate concentration test, since what is really important is knowledge of the degree of effort, determined by fatigue, something that the lactate concentration cannot give us.

Taking all these data as a whole, justified by the high validity shown, we can admit that this form of expression of the character of the effort (EC) allows us to advance in the knowledge of the load (effort) that is programmed and, especially, of the load that has been generated in each subject once the training has been completed.

As an initial practical application, if we take into account, as indicated above, that what is programmed is a series or orderly succession of efforts, if one wants to compare the effect of different ranges of intensity on changes in strength, or in other types of performance, one would have to control a key variable in performance itself, such as the effort generated, that is, the CE / degree of effort of each session through the IE.

This means that it would not only be necessary to cIt is not necessary to control that the relative intensity was real and that the loss of speed in the series is also controlled through a precise measurement, but it would be necessary to ensure that the IE was equivalent, and for this it would be necessary that the losses of speed in the series were different for each relative intensity, so that the efforts were equalized.. Only if this is done in this way, it could be accepted that the independent variable of the study is truly the relative intensity.

Only if the effort indices are equalized could it be accepted that the independent study variable is the relative intensity

To our knowledge, this control has never been carried out, so stating that entertainment with a relative intensity is better or worse than another is not relevant if the IE that has been generated with the different intensities is not equivalent.

The character of the effort (EC) quantified through the IE also has an important function as an independent variable, in such a way that it could provide information on the effect that each relative intensity can have, and other variables that constitute the training load, depending on the IE applied or generated.

Apart from the fundamental application as a control variable and as an independent variable, the quantification of the CE through the IE allows a better analysis of the effects of any design, being able to verify the relationship between the IE and the effects produced, apart from other variables with less discriminatory power such as the series, the number of repetitions per series and even the relative intensities, since the same value of these last variables can mean a very different degree of effort depending on what the values ​​of the others are.

As indicated above, today there is not enough data to be able to determine which IE is the one that can offer the best results, as well as with which variables this IE should be quantified or configured. Both issues must be considered, because, naturally, it is not the same to perform a squat training with an IE of 15, quantified by using 60% of the RM with a 15% loss of speed in the series (see table 16.12), than to train the same exercise with the same IE, but derived from using 85% of the RM and a loss of speed in the series of 25%.

Today there is not enough data to be able to determine which effort index is the one that can offer the best results, as well as with which variables this IE should be quantified or configured.

These two IE could generate a similar degree of fatigue, that is, a loss of speed with the load of 1 m s^–¹ very similar, but there is an important differentiating factor between both IE, which is the average speed with which the training would be carried out, much lower when 85% of the RM is used. This could lead to clearly different effects. All these issues must be taken into account if we really want to advance in the knowledge about training in general, and especially if we want to use the speed of execution as a reference for the dosage and control of the load and the effect it produces.

Table 4 presents a series of data that can be considered as the first information about what the trend of the effect of different values ​​of EI with different ranges of relative intensities may be. These are the real effects of two ranges of intensities: from 70 to 85% and from 55 to 70% of the RM in the squat exercise with different speed losses in the series.

In the first range he trained with four speed losses in the series: 10, 20, 30 and 40%. This resulted in the subjects training with certain IE, whose mean values ​​were 7.5, 14.8, 22.1, and 29.4, for losses of 0, 20, 30, and 40%, respectively. If we take into account that the groups that obtained the best results were those that lost 10 and 20% of the speed in the series, and that the extreme values ​​of EI of these two groups were 6 and 17, it can be suggested that these EI ranges are probably more favorable for improving performance with intensities between 70 and 85% than reaching higher values, between approximately 19 and 33. Or also, that average IE between 7.5 and 14.8 offer better results than values ​​higher than 22.1.

Probably average ranges of the Effort index for the squat exercise with an intensity of 70 to 85% between 7.5 and 14.8 offer better results than values ​​higher than 22.1.

In the second range of intensities, he trained with three speed losses: 10, 30 and 45%. This resulted in subjects training with mean EI values ​​of 9.6, 28.5, and 42.7, for speed losses in the set of 10, 30, and 45%, respectively. The group that performed best was the one that lost 10%, with EI values ​​between approximately 8 and 11, while EI values ​​greater than 25 do not seem to offer the best results. Therefore, given a range of relative intensities from 55 to 70%, applying IE between 8 and 11 may be more favorable than using IE of 25 or more.

Tabla 4. Effect of different values ​​of IE before different ranges of relative intensities. Explanations of likely effects are given in the table itself.

conclusions and practical applications on the effort index

• The high validity shown by the expression of the CE through the IE, as we do in this section, allows us to advance in the knowledge of the load (effort) that is programmed and, especially, of the load that has been generated in each subject once the training has been carried out.
• If we wanted to compare the effect of different ranges of intensity on changes in strength, or in other types of performance, it would be necessary to ensure that the IE was equivalent, and for this it would be necessary that the speed losses in the series or session were different for each relative intensity, so that the efforts were equalized. Only if this is done in this way, it could be accepted that the independent variable of the study is truly the relative intensity.
• Therefore, it is not pertinent to affirm that training with a relative intensity is better or worse than with another, if the IE that has been generated with the different intensities has not been controlled.
• The CE expressed through the IE can have at least the following applications:

1. 1. Act as an independent variable of any study on the effect of training.
   2. It is necessary and decisive as a control variable.
   3. It is very useful for a better analysis of the effects of any design, because it allows checking the relationship between the IE (degree of fatigue) and the effects produced.
   4. The choice of the speed of the first repetition and the choice of the loss of speed in the series or session can be done and in some cases should be done depending on the IE or degree of effort that we want to program.