The main contributions of execution speed in training are summarized below, and which have been explained in this other previous article. They are divided into four sections: the contributions of the speed of the first repetition, loss of speed in the series, percentage of repetitions performed with each loss of speed and the Effort Index.

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

• Assess a subject’s strength and accurately determine their true percentage of 1RM without ever needing to perform a 1RM test or XRM test
• Program, dose and control training with high precision.
• Use strength training with all subjects regardless of their age and physical condition.
• Know the degree of individual adaptation pre-post training (in all cases) and the evolution of individual adaptation over time.
• The loss of speed in the series, together with the speed of the first repetition allow estimating training fatigue.
• The effort index is an independent variable that allows you to compare any training.

Contributions derived from the knowledge of the average velocity (average propulsive velocity, preferably) of the first repetition of the first series of an exercise

• Evaluate the strength of a subject without the need to perform a 1RM test or an XRM test at any time.
• Determine with high pressure what actual percentage of 1RM the subject is using as soon as he performs the first repetition at maximum speed with a given absolute load:
  • Therefore, if the speed is measured every day, it can be determined with high precision if the absolute load proposed to the subject (kg) faithfully represents the true degree of programmed effort (% of real 1RM) as soon as the speed of the first repetition is measured. .
• Program, dose and control training with high precision through speed, and not through a theoretical percentage, not a real one, in most of the steps, of 1RM.
• 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. .

• Estimate the change in performance each day without the need to perform any tests, 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 were 0.08 m s^-1, when the subject increases speed by 0.08 m s^-1 Given the same absolute load, the load with which he trains will represent 5% less than the RM of the subject at that moment, so this will have increased in value. Naturally, if what occurs is a loss of speed at the same absolute load, we can be fairly sure that the subject is below its previous performance, and to a degree proportional to the loss of speed.
• If the speed of the first repetition is measured daily, weekly or simply before and after the training period or cycle, you can:
  • Know the degree of individual adaptation pre-post training (in all cases) and the evolution of individual adaptation over time (if speed is measured daily OR weekly).
  • Discover the degree of disparity in the adaptive responses of each subject.
  • Check the effect of improving strength on other types of performance or exercises, trained or not.
  • Assess the strength of athletes with minimal effort.
  • Check what real relative intensities have caused the training effect: something completely unknown until now in the history of training.
  • Verify that, in many cases, it may be enough to maintain an adequate progression of the absolute load, even though the relative intensity is stable or even tends to decrease throughout the training cycle.
  • Show that it makes no sense to talk about “periodized training or not” (assuming the term should ever be used, which we don’t think is necessary), as it “ideal” is that training “does not have to be periodized”, well keep the same relative intensity (according to the usual termology, “non-periodized training”) and even if the relative intensity tends to decrease (which could shock some and be described as “detraining”), as the absolute intensity increases of training is clear proof that the effect of training is very positive. In addition, a wide range of upper relative intensities is kept available and useful which might need to be applied at later stages.
  • Knowing what the minimum and maximum relative intensity at which each athlete trained really was and, therefore, not only knowing what the average effect was on the group, but also the individual effect of training and the load that caused it in each subject.
  • Know specific data on the possible magnitude of the differences in the training load that can occur between subjects, with the same characteristics, that, theoretically, they had to do the same training, having verified that there can be differences in relative intensity between subjects of up to 20% at the end of the training cycle which, supposedly, was the “same” for all.
  • Know the characteristics of the subjects as responders to training: differences in adaptation or response to training stimuli.
  • Be aware of the need to consider the importance of training individualization: by nature, it is not possible to train a group of subjects with “the same training.”
  • Realize that it is not possible to affirm that a certain training is “the best”. So we could say that “there are no trainings, but subjects who are trained or trainable subjects.”
  • Discover new approaches to reflect on the relationship between the burden and its effect in general terms and on each person individually.
  • Improve the training methodology, based on the contributions indicated in the previous points.
• Measure the speed with which RM is achieved. This is the only way to be able to consider an RM as “true” or “false”:
  • 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 ≥0.03 m s^-1, these RMs are not equivalent, so comparing the values ​​of the RMs (weights lifted) pre-post training would lead to wrong decisions, considering that there have been some changes of force (in the MRI) that are not real. In addition, the speeds with each percentage would appear to be different after training, without meaning that they really are.

• It allows to apply the best procedure for the assessment of the training effect, such as re-measuring the speed reached before the same absolute loads that were measured in the initial test:
  • This procedure is the most consistent, since allows us to check if the objective of all strength training is met: to improve speed at the same absolute load, and, in addition, to it is the most accurate, since the effect of strength training is measured by the change in velocity under the same absolute load.
  • Adjust the Load (intensity) to the actual physical situation of the subject in each training session.
  • Guarantee the control of a determining variable of the load and the performance, such as the relative intensity. If not controlled, this variable would become a powerful foreign variable, which would undoubtedly influence performance, so its control is necessary, which had never been possible to date.. We do not know of (probably does not exist) any more precise procedure to control / match the relative intensity than the speed of execution with the first repetition of the series.
  • Even the control of the loss of speed in the series, which we discuss below, no tendría sentido si no se tiene información precisa de la intensidad relativa de cada sesión, porque las pérdidas de velocidad serían ante intensidades relativas diferentes, con lo cual the loss of speed would lose all its power to control the load.
  • Know the real average relative intensity of the maximum intensities applied during a training period. Which can be expressed as average speed or, more intuitively, simply expressing the average speed as a percentage of the RM, since we know the percentage that a certain speed represents. For example, if the average speed has been 1 m^s-1 in the squat, the real relative intensity of the entire training cycle expressed in percentages of the RM would be 60% of the RM, and if the speed was 0.75-76 m·^s-1 would correspond to 75% of the MR.
  • Know the actual average relative intensity of all applied intensities, not just the maximum ones, during a training period.
  • Check the effects of training at different speeds (light, medium and high loads), as well as at the average speed of all common loads moved pre-post training. This type of measurement allows more information about the effect of training and minimizes the possible error in the quantification of its effects. For this reason, it is a measurement that clearly exceeds what the usual MRI measurement offers to assess the effect of training.

Contributions derived from the knowledge of the loss of speed in the series

• Fatigue depends on the speed of the first repetition in the set and the percentage loss of speed in the set.
• The training load can be quantified by the loss of jumping ability (actually, loss of speed) and the loss of speed at a given absolute load in each session.
• It allows checking the relationship between the loss of jump and the loss of speed at a given load (load of m·s^-1 in our case) per session and the effect of training.
• The loss of velocity pre-post training session with the load of 1 m s^-1 and the loss of CMJ are accurate estimators of the metabolic stress caused by the training session..
• At loads of approximately 70-90% RM, ammonium increases exponentially from a loss of velocity 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. The same can be expressed by saying that it is necessary to do 1-2 repetitions more than half of the possible in the series in any of the two exercises so that the ammonia exceeds the resting values.

• 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 speed loss in the set of 10-20% provided better results than a loss of 30-45%. In the bench press, a loss of 25-40% was better than 50-55%.
  • People who train for health probably shouldn’t do even half of the possible reps in the set. For example, they shouldn’t lose even 20% speed on the full squat set or 25-30% on the bench press.
  • For most experienced athletes with medium-high strength needs, it will probably be enough to perform at most half or 1-2 repetitions more than half of the possible ones. Although it is also estimated 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 (no more than 20% loss of speed in the series in the full squat or 25-30% in the bench press).
• Know the real average speed with which you have trained throughout the cycle individually and as a group.
• Know the real time under tension of the entire training.
• It is possible to know exactly the average speed lost in the series by different groups and by each participant:
  • If it is taken into account that what is always programmed is an EC / degree of effort, knowledge of this data is the most relevant of what can be expected in relation to the load applied or generated by the training already carried out.
  • Therefore, these indicators of fatigue are the ones that can get us closest to finding the relationship between the training performed and the effect produced:
• It allows us to reflect on the fact that with the same relative load, a difference of a few hundredths of more^-1 (0,08-0,1 m·s ^-1Therefore, these indicators of fatigue are the ones that can get us closest to finding the relationship between the training performed and the effect produced: and in some cases obtaining statistically significant differences in their favor.
• Together with the knowledge of the speed of the first repetition in the series, it solves the problem of distributing the repetitions performed by RM percentage zones when trying to quantify the training load. since this procedure encompasses all the drawbacks associated with the use of MRI as a reference to dose and assess the training load:
  • The solution to this problem lies in the use of speed zones instead of percentage zones, because the speed at which the charges have moved expresses very precisely what real relative intensity the subject has used.
  • This type of distribution makes it possible to analyze discrepancies in the training effect when the same repetitions have been programmed for all subjects at the same relative intensity.
  • If you don’t do it like that, following the traditional procedure of programming the same repetitions per set for all subjects, the least fatigued (those who can do more repetitions per set at the same relative intensity) they will present a greater number of repetitions at a higher speed, and, therefore, a higher average speed, which would not be reflected if the repetitions were distributed by percentages and not by speed zones.
  • It allows to locate all the repetitions in their true zone, which is not possible if the percentage of the RM is taken as a reference.
  • We understand that this type of information is the most relevant and precise to be able to carry out an analysis of the true load that has caused a certain effect., because it reflects very clearly the degree of effort made: number of repetitions with each relative intensity (in zones of one tenth of m·^s-1 difference).

• If we add to the above the information provided on the loss of speed, the average speed and the average maximum speed of the entire training cycle, we will probably have the series of variables that allow a better analysis of the applied load.
• Talking about the average speed lost during the entire training cycle, knowing the speed of the first repetition of each maximum training load, is like talking about the degree of fatigue generated for each group and each subject individually. If we take into account that what is always programmed is a CE / degree of effort, which represents a degree of fatigue, which, in turn, validates the CE itself, the knowledge of this data is the most relevant of what can be expected in relation to the knowledge of the load applied or generated by the training already carried out.

Contributions derived from the knowledge of the percentage of repetitions performed before each percentage of speed loss in the series

• 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 in all subjects. This allows us to affirm the following:
  • 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 for each subject 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 necessary speed losses will be 2.5, 5 and 10% less, respectively, than the losses corresponding to the intensities of 50 to 70%.
  • If it is the squat exercise, given the same percentage of speed loss in the series, from 50 to 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.
  • Being able to do the same 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 the RM. For this reason, 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 may be sufficiently different.
• If we take the loss of speed in the series at the same relative intensity as a reference, the efforts made will be very similar, although the number of repetitions made 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 one will have done a different percentage of the total number of possible repetitions in the series:
  • 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.
  • It is the loss of velocity in the set that equalizes the effort, not the number of repetitions performed in the set at the same relative intensity.
• Therefore, the loss of speed in the series equals 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 the speed can be measured, the repetitions in the series should never be programmed, but the loss of speed in the series.

Applications derived from the knowledge of the Effort Index (IE) as an indicator of the Character of Effort

Remember that de Effort Index (IE) is the result of multiplying the speed of the first repetition (best repetition, which should be the first repetition in almost all cases) in the series by the percentage loss of speed in the series. Therefore, it is conditioned by the two key variables: the speed of the first repetition and the loss of speed in the series:

• The high validity shown by the expression of the CE through the IE as an indicator of fatigue or degree of effort, allows to advance 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 compare the effect of different intensity ranges about the changes in force, or in other types of performance, it would be necessary to ensure that the IE was equivalent, and for this it would be necessary for the speed losses in the series or session to be 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:
  • Act as an independent variable of any study on the effect of training.
  • It is necessary and decisive as a control variable.
  • 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.
  • 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.

In this article, a series of actions are indicated to program the training in each of the cycles that are programmed throughout the sporting life of the trained subject, always keeping in mind the previous considerations exposed in previous articles.

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.

1. Select the variables that determine the load

Select the minimum speed of the first repetition in the series of the entire training cycle (relative maximum intensity of the cycle), the velocity loss in the series for the relative maximum intensity and the Effort Index (IE).

The IE is determined by the two previous indicators, and it could be the first thing to be programmed, if one had experience in the use of this index and data recorded and analyzed from previous training cycles, but since the same IE can be obtained with intensities different relative speeds and losses in the series, which would also give rise to different effects, First of all, it is necessary to choose the maximum relative intensity of the cycle (the load that moves at the slowest speed within the cycle) as a reference for the evolution of the training load throughout sporting life.

Therefore, in practice, it will be the first thing to decide. The second decision will be about the loss of speed in the series with the maximum relative intensity and the rest of the relative intensities.

The relative intensities could be expressed through real percentages of the RM, as it is more comfortable, intuitive and easier for assessment and communication between professionals and athletes. But these percentages of the RM will always be expressed and quantified through the speed with which the load must be moved, never by the calculation on a RM.

The decision on the values ​​of the relative intensities and speed losses in the series will be made based on age, experience in strength training, the strength needs of the sport and the initial situation of the subject.

2. Select the minimum intensity of the cycle and the loss of speed in the series with this load.

The next step to program training is to select the minimum intensity of the cycle (highest speed of the first repetition within the cycle), that is, the speed with which the first training sessions of the cycle are carried out, with the lightest loads, and the speed loss in the series for this relative intensity.

The speed losses with the lighter intensities will always be lower than with the higher intensities within the cycle. It must be taken into account that the same speed loss under a light load means greater IE (greater fatigue) than under higher loads. Therefore, the use of the same speed loss in the series before all the intensity would mean performing a higher IE with light loads. The basic orientation is that the loss of speed with light loads is lower.

With small loads, by reducing the loss of speed in the series, the repetitions performed will be proportionally further away from the possible repetitions in the series and the IE will be less than or equal to that achieved with high loads.

3. Determine the duration of the cycle.

This is a necessary step, but it is not conditioned by the fact that speed is used as a reference for training organization. The duration of the cycle, as a general rule, should not be more than 8-12 weeks. In addition, you can do cycles of 4-6 weeks that can also be very effective in certain situations. The duration of the cycle will tend to be longer at the beginning of the season and in the early stages of sporting life.

When the number of competitions in the season is not very frequent, for example, only in 2-4 short periods of time per year, the length of the cycles, apart from the adaptation times, is highly conditioned by the dates of the competitions. .

If the competitions are very frequent, what determines the duration or length of the cycles will be the adaptation times.

4. Determine training frequency

This is also a necessary step, but it is not conditioned by the fact of using speed as a reference for programming training. Two strength training sessions a week are compatible in most cases with the specific training of many sports specialties. But the most important thing is to choose well the frequency with which each exercise is trained, which preferably should not be more than twice a week. Weightlifting is naturally excepted from this general suggestion.

However, it must be taken into account that increased frequency does not necessarily mean increased load. If the same job is divided into two sessions, the frequency will increase, but the load will be the same or, with high probability, less, since the fatigue values ​​per session would be lower.

5. Distribution of the maximum intensities of each session, between the minimum and the maximum of the cycle

Depending on the values ​​of the minimum and maximum intensities chosen, it is decided how many intermediate maximum intensities will be used. For example, if the minimum intensity is equivalent to an intensity of 50% of 1RM and the maximum to 70%, 1RM (loads that, naturally, would be determined by speed), training could be programmed with intermediate intensities equivalent to 55, 60 and 65 % of 1RM.

Therefore, there would be five maximum intensities in total for all sessions. Once the training frequency of the exercise and the set of maximum intensities of each session are known, training can be programmed by distributing these intensities among the frequencies.

For example, if for the indicated intensities there were 20 sessions, which could correspond to 10 weeks of training, with two sessions per week the simplest distribution would be to train four times with each maximum intensity. Naturally, the distributions could be different depending on the cases.

This is not the time to develop all the possible alternatives, but as a guideline, it must be taken into account that given the same intensities and weekly training frequency, training can be programmed with different resulting global loads. This overall load will depend on the greater or lesser frequency with which the maximum expected intensities are used.

If instead of performing each maximum intensity four times, as indicated, 50% is performed 5 times, 55% 6 times, and the remaining three intensities are performed 3 times each, the average intensity of the cycle will decrease. If, on the contrary, a redistribution is made by increasing the frequency of the two higher intensities, the average intensity will rise. These changes in the frequency distribution of the maximum relative intensities is a way of modifying the load and progressing in the training demand without modifying the range of intensities used during the cycle.

6. Decide the number of series before each training intensity, especially before the maximum intensities of each session

The most frequent number of series to perform with each of these intensities will be between 2 and 4. And within this range, the most common is to do 3 series with the maximum intensity of the day. With the warm-up intensities, it is usual to use one series for each intensity, progressing until reaching the maximum intensity established (main load of the session). As already indicated, the repetitions to be performed in each series with the maximum intensities of the session are not programmed, as they will be determined by the selected loss of speed.

schedule training

Another component of the training load, the intensity depends both on the intensity’s own value and on the number of times (volume) that said value is applied. For this reason, whenever we talk about intensity, we will also talk about volume, and therefore, load.

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

• Intensity is the degree of effort developed when performing an exercise or training activity in repetition.
• The character of effort is the relationship between what has been done and what is achievable.
• The relative intensity is the percentage of the 1RM, which is the maximum weight that a subject can move in one repetition.
• The measurement of the 1RM displacing the maximum weight supposes an excessive effort and a risk for any athlete.

Training actions are rarely performed only once, the normal thing is to perform several times / several repetitions with a certain intensity. Therefore, both the intensity and the number of times each intensity is to be performed must be taken into account.

Intensity is the degree of effort developed when performing an exercise or training activity in each unit of action (repetition).

The intensity represents the degree of muscular activity developed to oppose a resistance, whether this resistance is constituted by one’s own body weight (which occurs with all the efforts that consist of jumping or moving the body in any medium without additional added loads), as if it were about overcoming an external resistance.

The most precise and sufficient way to determine the intensity when working with external loads is through the maximum possible speed of the first repetition in the series, but power could also be used when dealing with machines in which actions are performed. cycles that give power data as the product of force and speed. The maximum possible speed of the first repetition will always be accompanied by the maximum production of force in the unit of time (RFD) for the load, absolute, relative, with which you train.

The effort is defined as the degree of demand or demand on the organism (real load) of a physiological, mechanical, technical, emotional type in each unit of action. The relationship between the degree of demand and the current / real possibilities of the subject at a given moment constitutes the character of the effort (González-Badillo and Gorostiaga, 1993, 1995).

Therefore, the character of the effort is or expresses the load itself, that is, it defines it, and is determined by the relationship between what is done (degree of demand caused by the activity or work done, which is expressed by the series and repetitions performed before a determined absolute or relative determined load) and what is achievable (current possibilities of the subject, that is, the maximum work that the subject could perform: maximum number of repetitions in the series or in a set of series).

The character of effort is the relationship between what has been done and what is achievable. The maximum character would be the maximum number of repetitions in the series or set of series.

There are different ways of expressing intensity that are more in line with what is generally understood as “strength training.” Really, all training is strength training, because from a physical point of view, performance can only be improved by applying more force to the same load, that is, reaching more speed with the same load, which is what is intended with everything. type of training, except in weightlifting, in which the speed does not change, but the load that moves at the same speed.

absolute intensity

Weight (kg). Weight is an indicator of absolute intensity. It has the advantage that it can be used to compare the training of each subject with himself over time: speed change for the same load (weight). In addition, it is the best indicator of the relative load used by the subject and of the training effect if the speed with which each repetition is performed is controlled.

Relative intensity: Percentage of 1RM.

When it comes to displacing external loads the percentage of one repetition maximum (% of 1RM) could be used. This expression of intensity is typical of what we think of as “strength training.”

Advantages

This way of expressing intensity has some advantage, such as the fact that the load (weight) that each subject should use could be individualized, apparently in a simple way, no matter how large the training group was. You would simply have to indicate the percentage of 1RM with which you would have to train.

If the percentage of 1RM is considered and interpreted as “degree of effort” and not simply as an arithmetic calculation, it could also have an important application to indicate the evolution of the maximum relative load used in each training session or week.

If a person honestly wants to report his “philosophy”, his “theory” or his idea about training programming, he must do it simply, quickly and accurately indicating the maximum intensity (in this case the percentage of 1RM considered as “degree of effort”) of each session in the fundamental exercise or exercises.

This information is the most important, although, naturally, if the volume values ​​are added with each intensity, the information will be more complete. This is so as long as the percentages are real, that is, they accurately represent the true effort that each percentage represents.

Drawbacks

1 – Time misalignment of the theoretical percentage: The MRI value is not the same every day. It tends to increase in a few sessions if the subject is not highly trained, and is generally below the maximum value measured before (usually weeks, months, and even years before) starting the training cycle when subjects are highly trained. However, in neither of the two cases are the changes stable, but oscillations occur within the improvement or stagnation of the MR value.

For all this, the effort made during the session can clearly differ from the programmed one. The drawback of this error is usually much more serious in trained subjects than in beginners, since it would be the trained ones who would run the greatest risk of training with loads higher than those programmed..

A clear and negative consequence of this situation, whatever the level of performance of the subject, is that we will never know with what load we have –
trained, which is quite serious, since we will be considering that the effect of the training, good or bad, obtained is due to loads or efforts different from the real ones. Dragging this problem would never improve our training methodology, because we would almost always handle wrong data.

2 – That the value of the MRI is not real: A high percentage of the measured MRIs are false. Given that each exercise has a speed of its RM (González Badillo, 2000), the RMs will be false whenever the subject reaches his RM at speeds higher than the speed of the RM of the exercise (there is no other possibility of error because at measure 1RM the speed can never be less than the speed considered as typical of the RM of the exercise).

The more the speed at which the RM has been measured moves away from the speed of the exercise, the less accurate the measurement will be. This lack of precision is always manifested by resulting in an RM value that is lower than the real or true value, although, naturally, the true value of the RM will never be known.

Therefore, when we speak of “true value of the RM”, we must understand a value of RM reached at the speed of the exercise or very close to it. This means that each load (weight) that we use, taking a false RM as a reference, will always be a lower real percentage than the programmed one. This circumstance means that this error has fewer negative consequences for training than other errors, since we would always train with loads lower than those programmed.

3- The effort represented by each percentage of 1RM is different depending on the exercise: To the previous drawbacks we must add that, even if the real percentage of the RM represented by each weight is known, the effort represented by each percentage is different depending on the type of exercise. This different effort depends on the speed of the RM.

For example, a load of 85% 1RM represents a very different effort than a bench press and a power clean. These differences are due precisely to the fact that the speed of the RM is different for each exercise (González Badillo, 2000).

4 – The measurement of 1RM supposes an excessive effort and with risk for any athlete, and especially for young people: Based on what we have just indicated in relation to the inconveniences of measuring and using the RM as a reference, it is reasonable to conclude that the RM does not should never be measured. It can be estimated through speed.

With respect to the dosage, we have already given the arguments, and as regards the assessment of the effect of the training, it only serves, in a not very precise way, to know the effect of the training on the maximum load (loads that move at very low speed), but not for all other loads or speeds.

The measurement of 1RM supposes an excessive and risky effort for any athlete, and especially for young people.

XRM or nkM

This The way of expressing the intensity of the training indicates that the maximum possible number of repetitions should always be done with the load (weight) that is being trained. The X and the “n” represent the number of repetitions to perform. It is understood that being able to perform a certain number of repetitions means that you are working with a certain intensity or percentage of 1M, since with each percentage of 1RM you can perform, on average, a certain number of repetitions. This way of expressing intensity includes volume, and is very common in expressing training, especially when it comes to studies that intend to be published.

This way of expressing or dosing the training load does not present any possible advantage. So we will only talk about its drawbacks.

The first observation regarding this type of expression and dosage of intensity is that doing the same repetitions with a certain load does not mean that you are working with the same percentage. The maximum value of the range in which the number of repetitions performed at the same intensity is found, from 50 to 85% of the RM, can double the minimum value, with an average coefficient of variation of 20% (González-Badillo et al. al.. 2017). Therefore, two subjects who have trained with the same number of maximum repetitions per set may have trained with very different relative loads.

1RM should never be measured

The second observation regarding this type of expression of intensity is that it is not possible to perform more than one series with the same load (weight) and the same number of repetitions when this has really been the maximum possible for the subject in the first. series. Therefore, it is not realistic to propose a training such as: 3x10RM, which means that the subject must perform 3 series of 10 repetitions with a load (weight) with which, in the first series, they can only really perform 10 repetitions. .

Another big drawback is that, by always training with the maximum number of repetitions possible per series, Even if fewer repetitions are made in successive series with the same weight, at least the following negative effects can be produced: excessive fatigue, increased risk of injury, and reduced execution speed under any load. (high loss of speed in the series). All this can lead to reduced sports performance.

Lastly, it has been observed that performing the maximum number of repetitions possible in each series does not provide better results than performing the same number of series and fewer repetitions per series with the same relative intensity (González-Badillo et al., 2005; González-Badillo et al., 2006; Folland, et al , Izquierdo, Ibáñez et al. 2006 Groeller, 2016; Drinkwater, et al., 2007; Willardson, et al., 2008: Pareja-Blanco et al., 2017) nor on other untrained exercises (Pareja-Blanco et al., 2017)

From all that has been said, it can be deduced that it would be very reasonable for no XRM value to be measured, neither for training nor to assess the effect of performance.

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.

Throughout these articles, a series of contributions that can provide the effect of execution speed and its control have been reviewed. But for this it has been necessary for the loads to be moved at the maximum speed possible both in the execution of the exercise with which it was intended to know the relationship between percentages and speed and when estimating fatigue or the percentage of repetitions performed in the series or the calculation of the Effort Index.

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 results of these two studies showed a clear tendency to improve more when, after controlling for all possible known variables, the bar was moved at the maximum speed possible than when it was done at half that speed.
• The way to equalize or make very similar the degree of effort for different people before the same relative load is to equalize the loss of speed in the series.
• by measuring the speed of the first repetition it is possible to guarantee that the subject has trained with the programmed relative intensities
• The group that trained to achieve a loss of speed of only 20% of the initial speed showed a tendency to offer better results
• The group that trained until achieving a reduction of only 20% of the initial speed showed a tendency to offer better results

It could be argued that an important part of the contributions that have been discussed would not be applicable because to train with external loads it is not necessary to move them as fast as possible or it is even better to move them slowly voluntarily. When the variables that could influence the results are adequately controlled, the greatest training effect is achieved if the loads are moved at the highest possible speed (González-Badillo et al., 2014; Pareja-Blanco et al., 2014).

To address the problem of what effect speed of execution has on physical performance, the two studies cited in the previous paragraph and in previous chapters were carried out, one with the bench press exercise and the other with the squat. In both cases, they trained with loads between 60 and 80% of the actual RM. The percentages can be considered real because in each training session it was verified, through the speed of execution, what absolute load (mass) represented for each subject the percentage of the programmed RM.

Two groups were randomly formed: one (n=9 in the bench press and n=10 in the squat) that performed each repetition at the maximum speed possible (GV100), and another (n=11 in both exercises) that performed each repetition at 50% of the maximum speed possible (GV50).

In each exercise the two groups trained with the same actual relative intensities and the same sets and repetitions per set. That is, all the training variables were identical except for the speed of execution.

As can be deduced from the information provided about the programmed training and, especially, the training performed, the independent variable in this study was the voluntary speed of execution, and all the other variables with a possible influence on the dependent variable were controlled. It is true that the GV100 lost speed in the series and the GV50 did not lose speed, since all the repetitions of each series were done at the same average speed.

In addition, not only was the real percentage at which each group trained and the speed at which they performed the first repetition in each series in both cases controlled and known, but also the specific average speed at which each group trained. Since the execution speed for the same repetitions was different, there has been a difference between the groups derived and unavoidable from this circumstance, which is the time under tension. But, thanks to the measurement of the speed in each of the repetitions performed, we can have a precise assessment of the magnitude of these differences and assess the results despite this factor.

Since the speed was measured before all the loads in the initial test and in the final test, it was possible to incorporate in the analysis of the results the comparison of the mean of the VMP of the common pre-post training loads. This type of analysis is an important contribution based on the speed of execution and an important advance in the assessment of the training effect for two reasons:

i) because the improvement in physical performance, and in many cases in specific performance, in any sport is measured by changes in speed under the same load (mass). Only weightlifting is excepted, which consists of moving more and more load at the same speed, and

ii) because when using the same absolute load to evaluate the effects, the precision in the pre-post training reference loads for the comparison of the effects is the maximum possible. Furthermore, this comparison allows such a comprehensive assessment of training effects that one could (should) dispense with the comparison of MR changes.

In addition to the previously mentioned changes, it was possible to measure the effects of the training before light loads, that is, the loads that in the initial test moved at speeds ≥1 and ≥0.8 m s^-1, for the squat and bench press, respectively, as well as for heavy loads, which in the initial test moved at ˂1 and ˂0.8 m s^-1, for the squat and bench press, respectively. As can be easily deduced, these analyzes make it possible to check not only if the RM improves to a greater or lesser extent, and even if the average velocity improves with the set of loads measured, but also if the changes have been proportionally different in some areas or others of the force-velocity curve depending on the load used or, in this case, the type of execution performed.

The results of these two studies showed a clear tendency to improve more when, after controlling for all possible known variables, the bar was moved at the maximum speed possible than when it was done at half that speed. This result occurred despite the fact that the time under tension was higher in GV50, from which it can be deduced that, probably, a longer time under tension is not determinant for the improvement of strength. This variable cannot be considered as a strange variable, since it is a consequence of the different execution speed, and naturally has a directly proportional relationship with it.

A clear tendency to improve more when moving the bar at maximum speed shows the effect of execution speed.

It is hard to find a more precise procedure for measuring time under tension in strength training by accurately measuring the execution time in the concentric phase of the movement for each of the repetitions performed during the entire training cycle: this is another great application of speed control.

In fact, the incorporation of these two studies, carried out with a high control of possible extraneous variables, is not done at this time to show the effect of training on performance, but because it was necessary to justify the multiple applications of execution speed on the dosage, control and evaluation of training. Therefore, from what is stated in the description of the design we can deduce that an adequate use of speed allows:

• Dose / program the load (relative intensity) of the training through the speed and control that each training session is carried out at the programmed intensity through the measurement of the speed of the first repetition of the series.
• Know the real average speed with which you have trained throughout the cycle individually and as a group.
• Know the real time under tension of the entire training.
• Evaluate the effects of training in different zones of the force-velocity curve.
• Estimate and compare the changes on the RMs.
• Compare the changes in the mean of the VMP of the common loads pre-post training. This comparison could (should) allow to eliminate the comparison of the RMs.

Examples through studies on the effect of the loss of execution speed in the series

In the two previous articles, three studies have already been exposed in which the relationship between the loss of speed in the series y fatigue, metabolic stress, the percentage of repetitions performed and the creation of a Effort Index. In the first of them, the immediate effect of a greater loss of speed in the series with different relative loads on fatigue and metabolic stress has been analyzed, in order to estimate the degree of effort or load that a certain loss of speed entails.

In the second, it has been shown how the way to equalize or make very similar the degree of effort for different people before the same relative load consists in equalizing the loss of speed in the series, and not the number of repetitions that are performed in the series before the same relative intensity. And in the third, the necessary data have been provided to validate a new index, which we have called the Effort Index (IE), as a product of the speed of the first repetition in the series and the loss of speed within the series itself. .

The way to equalize the degree of effort for different people before the same relative load is to equalize the loss of speed in the series.

Once the information derived from these studies is known, what is proposed to contribute now is information on the applications of the speed of execution when it comes to trying to verify the effect that certain losses of speed have before different relative intensities, and, in some cases, also include information on the IE associated with these training sessions.

These are experimental studies in which the effects of different speed losses in the series are compared to different relative intensities. The implementation of these studies derives from the attempt to answer a series of questions. In the studies previously analyzed, it has been seen that, for the same absolute or relative load, the degree of fatigue is greater the greater the number of repetitions performed in the series, or rather, the greater the loss of speed in the series. The questions now would be the following:

• What is the degree of fatigue necessary to obtain the best results? Based on what has been exposed when talking about the drawbacks of load dosage through an XRM, it seems that reaching muscle failure or trying to reach maximum volume in the series is not the best.
• But what load / degree of fatigue / volume below the maximum achievable are the most suitable?
• If the load of each training session is defined by the fatigue it causes, how do we quantify fatigue and check its effect? In this sense, it is probable, as we have seen, that one of the most precise and easy to apply procedures is the loss of speed in the series, which, moreover, is in accordance with what is stated in the classic texts where fatigue is defined as the loss of strength or loss of speed or loss of power before a determined load.
• But what degree of speed loss is most effective? Naturally, it is not possible to verify in a single study all the possible combinations of speed stalls and relative intensities and subjects on which they are applied. But it is necessary to continue advancing in this sense if the aim is to improve the training methodology. To carry out this task it is essential to make adequate use of speed control, both to define the relative intensity and to quantify fatigue.

The study being analyzed (Pareja-Blanco et al., 2017) aimed to verify the effect of two percentages of speed loss (different degrees of fatigue) training with the same relative intensity. The only training exercise was the squat. He trained for eight weeks, two sessions per week. The relative intensities oscillated between 70 and 85% of the real MR, and were applied progressively. Three series were performed with the maximum intensity of the day.

The independent variable was the loss of speed in the set, which means that a certain number of repetitions per set was not programmed. Each subject performed repetitions in the set at the maximum speed possible until the programmed speed was lost. This means that not all the subjects of the same group performed the same repetitions neither in the series nor, naturally, in the training session. Common training variables within the group were velocity loss in the set and relative intensity.

For one group (n = 12) a loss of speed in each series of 20% was programmed with respect to the speed of the first repetition with the maximum intensity of the session (G20). For the other group (n = 10) an approximate mean loss of 40% (G40) was programmed.

The contributions of having been able to measure the speed in each of the repetitions performed by each subject throughout the training are multiple and relevant. Some of them are highlighted below.

• Only by measuring the speed of the first repetition is it possible to guarantee that the subject has trained with the programmed relative intensities, also allowing another important objective, such as adjusting the load (relative intensity) to the actual physical situation of the subject in each training session. This in turn guarantees control of a determining variable of load and performance, such as relative intensity. If not controlled, this variable would become a powerful foreign variable, which would undoubtedly influence performance, for which reason it was necessary to control it, which in this case was done by equalizing the speed of the first repetition of the first series with the maximum load of the day in all subjects. We do not know of (probably does not exist) any more precise procedure to control / equalize the relative intensity used by different subjects than the speed of execution with the first repetition of the series.

Only by measuring the speed of the first repetition is it possible to guarantee that the subject has trained with the programmed relative intensities, also allowing another important objective, such as adjusting the load (relative intensity) to the actual physical situation of the subject in each training session.

In the study that concerns us, the independent variable has been the loss of speed in the series. But this loss would not have made sense if the relative intensity of each session had not been controlled, because they would have been speed losses at different relative intensities. This control can only be done by measuring the speed of the first repetition, which should have been the same for the two groups. Indeed, the mean speed of the first repetition of all the sessions was practically the same for G20 (0.76±0.01 m s^-1; CV = 1.3%) than for G40 (0.75±0 02 m·s^-1: CV = 2.6%), and with a similar and very small variability.

These data, in turn, allow us to know the real average relative intensity of the maximum intensities applied, simply expressing the speed as a percentage of the RM. In this case, a speed of 0.75-76 m s^-1 corresponds to 75% of the RM in the squat exercise (Sánchez-Medina et al., 2017)

• As in the previous studies, measuring speed makes it possible to check the effects of training at different speeds (light, medium and high loads), as well as at the average speed of all common loads displaced pre-post training, not only at MRI, as usual.
• It is possible to know with high precision the average speed lost in the series by the different groups and by each participant. In the study analyzed, the mean loss of exact speed was 20.4 ± 1.5% of the speed of the first repetition of each series for G20 and 41.9 ± 1.9% for G40. The low value of the standard deviation (CV of 7.3 and 4.5% for G20 and G40, respectively) indicates that these losses were very similar for all subjects in the same group.

Talking about the average speed lost during the entire training cycle is like talking about the degree of fatigue generated for each group and each subject individually. If we take into account that what is always programmed is a CE / degree of effort, which represents a degree of fatigue, which validates the CE itself, knowledge of this data is the most relevant of what can be expected in relation to the load applied or generated by the training already carried out.

• In this study, since the speed has been measured in all the repetitions, it is possible to know the Mean Propulsive Velocity (VMP) of the total repetitions performed during training with the maximum loads in each session, which in this case was higher in G20 (0.69±0.02 m s^-1) significantly than in the G40 (0.58±0.03 m·s^-1).

Since in this study the G20 has shown a tendency to offer better results, this greater speed before the same relative load confirms the results of the studies in which the effect of execution speed was compared with the same relative intensity, in which the groups that carried out the training at a higher speed tended to obtain better results. It also allows us to reflect on the fact that with the same relative load, a difference of only 11 hundredths of more^-1 in the average speed (0.69-0.58 m s^-1) can generate effects with a clear trend in favor of the group with the highest average speed (G20) and in some cases obtaining significant differences in favor.

The group that trained until achieving a reduction of only 20% of the initial speed showed a tendency to offer better results

To know the total number of repetitions performed during training, it is not necessary to measure the speed, it would only be necessary to count repetitions. However, if the loss of speed in the series has been very similar for each of the subjects in the same group (20.4±1.5% for G20 and 41.9±1.9% for G40), a high variability in the number of repetitions performed for the same loss of speed would allow us to confirm that it would not be correct to program the same number of repetitions with the same relative intensity.

Indeed, in the present study, the number of repetitions performed with the maximum intensities of each session was 185.9±22.2 repetitions for G20, which means a CV of 12%, and for G40 310.5±42, with a CV of 13.5%. This means that, in G20, taking 1 standard deviation above and below the mean number of repetitions performed, in the extreme values ​​of 68% of the subjects there was a difference of 44 repetitions (±1 dSt), and of 88 repetitions if we go to the extreme values ​​of 95% of the subjects (±1.96 dSt). In the G40 these repetition values ​​were 84 and 168 for one and two standard deviations, respectively.

This means that the degree of fatigue in the subjects of the same group was very similar, as indicated by the average value of speed loss in the series and the low standard deviation, but the range of repetitions performed is wide, confirming the error that can be made when the same number of repetitions is proposed to all subjects at the same relative intensity. In the cases of the G40, the calculations indicate that an approximate difference of 10.5 repetitions of half a session was produced (168 repetitions/16 sessions). This information can only be obtained if the speed of execution is measured.

• Whatever the procedure for determining the training load, the two most determining factors, and unique to the same exercise, are intensity and volume. In the type of training that we usually call “strength training” the volume must be represented by the repetitions performed. But it is clear that two workouts with the same volume can represent two very different loads depending on the intensity with which they have been achieved. Therefore, a volume value without an intensity indicator does not make sense because it does not provide sufficient information about the degree of charge. If we add the average intensity value to the volume value, the information is higher. But an average value (an arithmetic mean) does not detect the variability of the data or the extreme values, so two equal volumes with the same average intensity can represent two very different loads depending on how said volumes have been distributed among the intensity values. For example, a 20 rep 70% 1RM workout has the same volume and average intensity as 4 reps at 50%, 4 at 60, 4 at 70, 4 at 80 and 4 at 90%, however these are clearly two very different workouts. Therefore, to adequately define the load before the same exercise, it is necessary to know the volume and the volume distribution between the intensities.
• In order to distribute the volume among the intensities used, intensity zones are usually created, from the smallest values ​​to the highest, with usual intensity limits per zone of 5%. For this, different percentages of the RM are taken, for example, from 40-45%, >45-50; >50-55… and so on. But as we have indicated, using the RM as a reference to dose the training is very likely to introduce a lot of error, in the sense that the real percentages represented by the absolute loads used could be very different from those programmed. Indeed, The solution to this problem lies in the use of speed zones instead of percentage zones, because the speed at which the charges have moved expresses very precisely what real relative intensity the subject has used.

This type of distribution makes it possible to analyze discrepancies in the training effect when the same repetitions have been programmed for all subjects at the same relative intensity.

Less fatigued subjects (those who can do more repetitions per series) will present a greater number of repetitions at a higher speed, and, therefore, a higher average speed.

Therefore, the distribution of repetitions by speed zones allows:

• Differentiate the degree of effort made by each subject.
• Analyze the load-effect relationship or the execution-effect relationship of the training.
• It allows all repetitions to be located in their true zone, which is not possible if the percentage of the RM is taken as a reference. For example, if a subject performs 6 repetitions with 75% of the RM, all the repetitions would go to the zone in which the 75% is found, when in reality, not all the repetitions have been carried out at the same speed, that is, not all the repetitions have meant the same effort, so the information on the degree of effort made, which is the key to quantifying the load and the effect of the training, will be very imprecise. If, on the contrary, the speed with which those same repetitions were made had been measured, each of them would have been located in the corresponding speed zone, which would not be the same for all of them, thus indicating the effort that the series has meant in a much more precise way.

The distribution of repetitions by speed zones can be a powerful tool to explain the training load and its effect.

Figure 1 shows an example of the consequences of quantifying the training load taking as a reference the repetitions to be performed in the series versus programming the loss of speed in the series in two subjects with different characteristics.

If the training is programmed through the number of repetitions (text with a yellow background), everything that appears in the rest of the figure also results with a yellow background:

• The programmed number of repetitions is the same for both subjects: 7.
• The relative intensity is the same, since both start the training at 1 m s^-1 in the first repetition.
• The two perform 7 repetitions, but subject 1 has reached a speed of 0.7 m s^-1 in his last repetition, while subject 2 has reached 0.82 m s^-1, which means that :
• Subject 1 has lost 30% of the speed of the first repetition, his average execution speed has been 0.85 m·s^-1 and he has performed 5 repetitions at ≥0.8 m·s^-1.
• While subject 2 only lost 18%, he reached an average speed of 0.91 m·s^-1 and performed 7 repetitions at ≥0.8 m·s^-1.

All this means that both subjects, although they have trained with the same relative intensity and with the same number of repetitions, have made a quite different effort, that is, they have carried out two different training sessions, determined by a greater degree of fatigue and by a lower average speed of subject 1 compared to 2.

However, if the same loss of speed is programmed in the series with the same relative intensity, everything that appears with a green background in the figure occurs:

• The two subjects lose the same speed in the series and perform the same average speed in the total number of repetitions, even though subject 2 has performed 5 more repetitions.

Differences between programming the same number of repetitions against the same loss of speed.

Figure 1. Differences in the training load between programming, at the same relative intensity, the repetitions to be performed in the series or programming the loss of speed (see text for further clarification).

In this case, the two subjects have reached the same degree of fatigue and have trained at the same average speed. This is what defines the training load, taking the number of repetitions to the background and being something almost anecdotal, as long as these requirements are met:

• Same speed on the first repetition.
• Maximum possible speed of execution in all repetitions.
• Same loss of speed in the series.

If this is the case, the training loads, the efforts, the fatigue, the average speed of execution and the IE will be the same for the two subjects, although in the count of the repetitions the number performed is different in each case.

Definitely, this type of information is the most relevant and precise to be able to carry out an analysis of the true load that has caused a certain effect, because it reflects very clearly the degree of effort made.

Continuing with the study data, a real example of the information that the distribution of repetitions by speed zones can provide is given. Table 1 shows this distribution of repetitions between the different speed zones.

Tabla 17.1. Distribution of the repetitions performed, including the warm-up, between different speed zones (relative intensity).

The G40 performs more repetitions than the G20 because it loses more speed in the series. Este mayor número de repeticiones se produce en todas las zonas de velocidad excepto en la zona >1,1 m·-s^-1, en la que están prácticamente igualados. But the differences are manifested mainly in the areas ≤0.7 m·-s^-1, which clearly lowers the average speed of execution during the cycle from 0.69 in G20 to 0.58 m·-s^-1 in the G40 with the maximum loads of each session.

It is reasonable to accept that this lower average speed, although apparently small, of only 0.11 m·-s^-1, is responsible for the lower performance obtained by the G40, especially under light loads (2), because it cannot be deduced that this lower performance is due to the fact that they did fewer repetitions with high speeds, because with the speeds from >0.7 to 1 m·-s^-1, the G40 also performs more repetitions than the G20. Therefore, the number of extra repetitions that the G40 has performed for having continued doing repetitions after losing 20% ​​of the speed, does not seem to have contributed anything positive.

It is also worth noting the fact that small differences in average speed, such as 0.11 m·-s^-1, can give rise to quite different effects, in this case in favor of the higher average speed. Although, if this is so, we could give another interpretation to this “small” difference in speed, considering that these differences “are not so small”, but large enough to cause clear changes in performance.

In this sense we add another great advantage of speed control, which is explained as follows. If the distribution of the repetitions by zones of percentages of the RM had been made (we must take into account that this was a great advance in the control of the training load at the time, and that it comes from the technicians and researchers of the former Soviet Union, especially from Russia), and we wanted to know the average intensity of the entire training cycle, we would be forced to multiply the average value of each intensity zone by the number of repetitions performed in each zone, later calculating the weighted average derived from all these products.

For example, if the zone were ˃65-70, we would multiply 67.5 (the mean of 65 and 70) by the number of repetitions performed in that zone, and so on for all other zones. In this way we would have an approximate average training intensity. However, having measured the execution speed of each repetition, we have the exact average execution speed of all the repetitions of the cycle, without the need to make subsequent approximate calculations in a similar way as we have described for the percentage zones. This calculation could also be done with the speed zones, but, in addition to being unnecessary, the results would be much less precise.

In relation to the above, it should also be taken into account that the average speed of the entire cycle could be expressed as a percentage of the RM, simply by checking what percentage of the RM corresponds to the average speed performed. In the example of the study that we have been commenting on, the average speed with the maximum loads of each session was 0.69 m·-s^-1 for the G20, which is equivalent to having trained with a relative and average intensity of 80% of the RM (80% corresponds to a speed of 0.68 m·-s^-1), and the G40, whose average velocity with these charges was 0.58 m·-s^-1, with 85% (85% velocity is 0.59 m·-s^-1).

That is, the difference in the average percentage of the RM was slightly more than 5%. Here another important advantage of speed control is manifested, since having made the calculations and the distribution of the repetitions through the percentages, apart from the imprecision derived from the calculations, already mentioned, the big problem is that a significant part of the repetitions have not been done with the programmed percentages, and, therefore, the repetitions are not in the real zones that should correspond to them, given the inevitable changes in the RMs values. All of this is overcome by using speed to control the training load.

If we add a complementary study to the study that we have been discussing (Rodríguez-Rosell, Doctoral Thesis) in which, training with the same relative intensities, the speed losses were 10% (G10) and 30% (G30) of the MRI speed, we can obtain even more information and confirm what we have already obtained.

Table 2 shows the distribution of repetitions by speed zones of this new study together with that of the previous study. The results of the groups that lost 20 and 40% of the RM have already been compared. Now it is interesting to compare the group of 40 with the one of 10% loss of speed.

The G10 performed better than the G40, especially in actions performed at high absolute speed, that is, with light loads, and even in an exercise performed at high speed, not trained, such as the CMJ (counter movement jump). El G10 no solo realizó muchas menos repeticiones en el ciclo de entrenamiento que el G40 (46,7% de las que realizó el G40), sino que, a pesar de haber mejorado claramente mas con cargas ligeras, realizó menos repeticiones con las cargas de alta velocidad (>0,8 m·-s^-1).

These results confirm the importance that the loss of speed in the series can have in the results and in the quantification of the training load. Because, as previously noted, it seems clear that, again, the G40 doesn’t improve less under high-speed loads because it didn’t train with it, but rather because it continued to lose speed beyond what the data indicates it should lose.

Repetitions performed by speed zones according to loss of speed in the series in the squat exercise

Tabla 2. Distribution of the repetitions performed, including the warm-up, between different speed zones of four training groups with the same relative maximum intensities and different speed losses in the series.

With the information contained in Table 2, numerous analyzes can be carried out, which will have the great advantage that they will be based on very precise data on the real load that each group or each subject has carried out, because the two variables that determine the load are being accurately reported: intensity and volume.

The relative intensity of each session is programmed through the speed of the first repetition, but Table 2 shows the frequency with which you train with each relative intensity, that is, the true training and the true intensity with which you train. has trained. In turn, this frequency and the total number of repetitions performed (volume) are conditioned by the loss of speed, which is also programmed.

The volumes by groups are comparable, because it is assumed that in each group there must be the same or a similar number of subjects who can do both a high and a low number of repetitions, as well as the average number of repetitions that can be done before each loss of speed. But this cannot be applied to compare individual subjects, because one of them could do many more repetitions than the other with the same loss of speed.

Therefore, volume as an indicator of performance between individual subjects should not be an important reference data for analyzing training load and its effects. Given the same loss of speed in the series and the same speed of the first repetition, the loads will be equivalent, even if the volumes are different. Which does not mean that if the charges are equivalent, the effects are also equivalent.

volume as an indicator of performance between individual subjects should not be an important reference data for analyzing training load and its effects

But precisely from here arises a new way of analysis provided by speed control, in such a way that this control can modify what is considered almost a principle “the same training load can produce a very different effect in different subjects”. But, really, when you say this, are you talking about the same load? We would bet that this has never happened, because always the proposed load, especially the repetitions in the series “have had to be the same for everyone”, because “the repetitions that offer the best results are xxx”.

It is evident that few subjects in the same group train with the same load if they all do the same repetitions in the series. Therefore, it would remain to be verified to what extent the same real load has different effects for different subjects and to what extent these differences would occur. At this time, we have data to begin to answer these questions, but this is not the time to deal with them now.

As can be deduced from everything that we have been exposing, speed control and proper handling of the information it provides can be an important and powerful tool for learning what it means to train.

Figure 2 shows the results of the two studies that have been discussed. In it you can see the clear tendency to improve more under light loads (7 and 66% vs. 0.8%) and in the CMJ (9.1% vs. 3.7%) when 10 and 20% of speed is lost vs. 40%, and they improve practically the same, or even somewhat more, in percentage terms, with high loads or when moving at low speeds (lower area of ​​the force-velocity curve), an area for which, according to the literature, it is necessary to train until muscular failure. In the lower left part, the IE reached by each group appear before the maximum training loads. The table on the right shows the sums of the improvement percentages of each group in the set of dependent variables.

Figure 2. Effect of four requests for speed in the series with respect to the first repetition before the same maximum relative intensities: 70 to 85%. Vel_–med(%): average speed with all absolute loads common to the initial test; Vel_–≥ 1 m·s^-1: speed with loads equal to or greater than 1 m·s^-1 of the initial test; Vel_–˂ 1 m·s^-1: speed with loads less than 1 m·s^-1 of the initial test.

Figure 3 shows the results of these same training sessions in the 20 m race. It is confirmed that not only in the tests with loads or the vertical jump the effects of a low loss of speed are more favourable, but that this same tendency is also manifested in actions with a higher absolute speed of execution, such as the 20 m race. To the right of the figure the sum of improvements of the different groups is indicated. With 10 and 20% of speed loss there is an improvement in times, while it tends to increase when 30 and 40% are lost.

This exercise was not trained during the time the study lasted. We are, therefore, before a true transfer test (positive and negative, depending on the case) of the training of the complete squat on the 20 m race. It seems reasonable to accept that the determining factor for one type or another of transference to occur is not the relative intensity, but rather the degree of fatigue generated in the series.

The determining factor for one type or another of transference to occur is not the relative intensity, but the degree of fatigue generated in the series.

Figure 3. Effect of four speed losses in the series with respect to the first repetition before the same maximum relative intensities: 70 to 85% on the times in the 20 m race.

What was commented at the end of the previous paragraph puts us before one of the important and permanent objectives of the training task, which is to know the effect that the improvement of a training exercise can have on a different exercise, whether this is also trained or not. It is, therefore, before the much brought and carried transference, but well understood. The answer to this question, as we have already pointed out, can be given by the fact of measuring speed in each training session, thus giving us a new important application.

If the training effect is assessed every day without doing any special test, but simply by measuring the speed of execution with absolute loads, we will have the evolution of the training effect permanently updated and, therefore, the changes that it produces in the measured variable throughout the cycle. But if, in addition, we measure some other type of performance in some exercise every week, trained or not, we will be able to verify to what extent the changes in performance in both exercises are or are not related and in what sense.

Well, in a study in which the effect of training with three degrees of effort was compared: speed loss in the series of 10, 30 and 45% of the first repetition of the series, at intensities between 55 and 70% of the RM, in the squat exercise, the correlation between the weekly changes in the RM in the squat and the weekly changes in the vertical jump (CMJ) was analyzed, which was not trained, but only was measured once a week. This same analysis was carried out with the data from the previously described study in which 10 and 30% of the speed was lost at relative intensities between 70 and 85%.

This made it possible to analyze the relationship between the changes of both variables on five occasions, three in the first study mentioned in the previous paragraph and two in the second study. The results indicated the same trend in all cases. Figures 4 and 5 show the correlations obtained.

Figure 4. Relationship between changes in MRI (axis X) and changes in vertical jump (CMJ) (axis Y) with respect to the initial test during the eight weeks of training and the final test, with speed losses in the series of 10, 30 and 45% and intensities between 55 and 70% of the RM (Calculations made with data from the Doctoral Thesis of Rodríguez-Rosell, 2017).

Figure 5. Relationship between changes in MRI (axis X) and changes in vertical jump (CMJ) (axis Y) with respect to the initial test during the eight weeks of training and the final test, with speed losses in the series of 10 and 30% and intensities between 70 and 85% of the RM (Calculations made with data from the Doctoral Thesis of Rodríguez-Rosell, 2017) .

It can be seen that the corrections are all significant and with a high explained CMJ variance, from 62.4 to 92%. These relationships are independent of the fact that the training effect is greater or better on the two variables analyzed.

In figure 4, the group that improved the jump the most was the one that lost 10% of the speed in the set, and in this group there is the highest correlation between the changes, but the second highest correlation is with the loss of 45%, which was the group that tended to have worse results in the squat. And in figure 5 the correlation is higher with the loss of 30%, who had worse results in the jump and squat than the group that lost 10% of the speed.

In all cases, moreover, it can be considered that we are dealing with five cases of true positive transfers, since the jumping exercise was not trained during the training cycle. That is, the correlation is not high because good results have been achieved in the tests, but because the changes in the squat, whether they are good or bad, tend to produce a change in the same direction in the CMJ.

Therefore, these results show an important contribution of the measurement of speed, because it allows us to confirm that, with different degrees of fatigue and effort, that is, with different IE, both the improvement and worsening of the squat have an effect in the same direction on jumping capacity. And that this is also true whether the fatigue in the series is light, such as losing 10% of the speed in the series, or if it is very severe, practically to failure, such as losing 45% of the speed in the squat exercise.

But if Figure 6 is observed, where the evolution of the RM and CMJ variables is graphically represented in the example of the study of the three losses, it is still possible to obtain more relevant information to know the effect of the training.

Figure 6. Evolution of the RM (central part of the figure), the CMJ, which was not trained, (upper part of the figure) and the IE (lower part of the figure) during the eight weeks of training plus the initial and final test in both exercises when all groups trained with intensities of 55 to 70% and with speed losses in the series of 10, 30 and 45% of the RM (Image taken from Rodríguez-Rosell’s doctoral thesis).

The evolution of the MR (central part of the figure) with speed losses of 10 and 30% is very similar, especially after week 4, to reach the final test with practically the same improvement values: 22.5% with 10% loss of speed and 22.7% with 30%. However, if we look at the top of Figure 6, we see that CMJ improves almost uninterruptedly from the start of training to the end in the 10% loss group, while this is not the case with the 30% group, with a final improvement of 11.8% in CMJ in the 10% group and only 3% in the 30% group.

It is understood that what these data provide should be taken very seriously. How many times have you heard that the squat is not adequate, or that it is harmful, or that it is not specific because the angle in which the deep squat is performed is not suitable for jumping and other exercises, such as running, or that “maximal strength training” is not suitable for jumping improvement, but “explosive / ballistic training”…?

But, of course, all this with little evidence, or with erroneous evidence, that can confirm it. However, as can be deduced from the data that has just been discussed, and from the rest of the studies that we have previously seen, the squat can be decisive for improving the jump, and the race, but it depends on how it is trained. The problem is not in the exercise, but in the load that is applied when training it.

If we focus on the statement about “maximum strength training”, the reflections can be very relevant. You would be hard pressed to find many people who would consider it “maximal strength training” to train with very low repetitions at 70% (3-4 repetitions), 80% (2-3 repetitions), or 85% (2 repetitions) of the RM, which is what the group that lost 10% of speed in the set did at these relative intensities.

We do not know what this training would be called, because it is most likely that it is not even considered as a possibility of training, and, therefore, it would not have a name. We also do not believe that it would be clear what name would be given to a training in which 5-6 repetitions were done with 55%, 3-4 with 65% or 70% of RM, which is what the group that lost 10% of speed did at these relative intensities. However, almost all those consulted would surely agree that reaching almost muscular failure, and in some sessions to failure, with intensities of 70 to 85%, if it is “maximum strength training” (some might say that it is “hypertrophy training”, not “maximum strength”, to introduce a little more error), which is what was done when the groups lost more than 40% of the speed in the series.

However, if we now go to the results obtained with each type of training, it turns out that the training that “are not strength” have improved RM (which for most is almost the only indicator of what “maximum strength” is) more than “those who are of maximum force”. For the intensities of 70-85 and 55-70% of the RM, with the speed losses of 10% the RM improved by 17.9 and 22.5%, respectively, and for the losses of 40-45% the improvements were 13.5 and 15.1%, respectively. This was also accompanied, especially, by a greater improvement in the jump: 9.1 and 11.8% for losses of 10% of speed in the series, compared to 3.7 and 5.4% when 40-45% of speed was lost.

It turns out that “non-maximal strength” workouts have improved RM more than “maximal strength” workouts.

So, as can be deduced, this is all quite painful and unfortunate: “non-maximal strength” training improves “maximal strength” the most, and the “bad” full squat improves jump height very clearly, moreover, without training the jump.

On the other hand, when it is said that “maximum strength training” is not suitable for improving jumping, but rather “explosive training” or “ballistic training”, a big mistake is being made, because, as we can see, the training that improves “maximum strength” is not only the one that is done until failure or with very high intensities, and until failure, but also other training with much lower intensities and with the generation of little fatigue, and it seems that with better results.

In addition, it turns out that the jump clearly improves without jumping, that is, without doing “explosive” or “ballistic” training. This means that you also improve maximal strength (properly understood) in jumping with “non-maximal strength” training. Naturally, all this is the consequence, as we have indicated in other sections, of a misinterpretation of the concepts related to strength training, especially the very concept of “maximum strength”, the main source of a long chain of errors, as well as the great mistake of believing that “maximum strength” can only be trained and improved by training to failure and high intensities, which, naturally, are also done to failure. In short, a rather discouraging panorama, but one that should help us to react and try to make sense of all these issues.

In short, as can be gathered from the results of these five training groups, it seems that maximum strength (well understood, not just RM) can be improved significantly with a wide range of intensities, but the training that generates the most fatigue with these intensities is never the one that tends to offer the best results.

It seems, therefore, that the degree of fatigue created by any relative intensity and, therefore, the average training speed of the entire cycle, are determining factors of the effect that is produced. In addition, the most precise way to adjust and estimate fatigue, as well as to measure, and know, with high precision, the speed at which the training is executed is through the control of the loss of speed in the series for each speed of the first repetition, that is, for each relative intensity.

Several conclusions and practical applications can be deduced from the above:

• In addition to determining the relative intensity with which you train, the speed of the first repetition allows you to achieve other important objectives:
  • Adjust the load (intensity) to the actual physical situation of the subject in each training session.
  • Guarantee control of a determining variable of load and performance, such as relative intensity.
  • Know the real average relative intensity of the maximum intensities applied.
• The speed measurement allows us to check the effects of training at different speeds (light, medium and high loads), as well as at the average speed of all common loads moved pre-post training. This type of measurement allows more information about the effect of training and minimizes the possible error in the quantification of its effects. For this reason, it is a measurement that clearly exceeds what the usual MRI measurement offers to assess the effect of training.
• It is possible to know exactly the average speed lost in the series by the different groups and by each participant:
  • If we take into account that what is always programmed is an EC / degree of effort, knowledge of this data is the most relevant of what can be expected in relation to the load applied or generated by the training already carried out.
  • Therefore, these indicators of fatigue are the ones that can get us closest to finding the relationship between the training performed and the effect produced.
• The measurement of speed allows us to reflect on the fact that with the same relative load, a difference of only 11 hundredths of more^-1 in average speed (for example, 0.69-0.58 m s^-1 in the case that we have presented), it can generate effects with a clear trend in favor of the group with the highest average speed and in some cases obtaining significant differences in favor.
• Faced with a loss of speed in the series that is equal or very similar for each of the subjects, there is a high variability in the number of repetitions performed. This confirms that it would not be correct to program the same number of repetitions with the same relative intensity. This information can only be obtained if we measure the speed of execution.
• In order to distribute the volume (repetitions) between the intensities used, intensity zones expressed in percentages of the RM have traditionally been created. But this procedure encompasses all the drawbacks associated with the use of MRI as a reference to measure and assess the training load. The solution to this problem lies in the use of speed zones instead of percentage zones, because the speed at which the charges have moved expresses very precisely what real relative intensity the subject has used:
  • It is understood that this type of information is the most relevant and precise to be able to carry out an analysis of the true load that has caused a certain effect, because it reflects very clearly the degree of effort made: number of repetitions with each relative intensity (in zones of one tenth of m s^-1 difference).
• If we add to this the information provided on the loss of speed, the average speed and the average maximum speed of the entire training cycle, we will probably have the series of variables that allow a better analysis of the applied load.
• In addition, the correct selection of the load by controlling the speed of the first repetition and the percentage of speed loss in the series, not only allows obtaining more improvements in performance, but by doing it in conditions of less tissue stress, it is very likely that it will contribute to the reduction or abolition of the number of injuries caused by strength training or any other physical training.

The correct selection of the load by controlling the speed of the first repetition and the percentage of speed loss in the series contributes to the reduction of the number of injuries caused by strength training or any other physical training.

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.