The Failure of Intensity Cycling: Training to Fail Pt. 3

Posted on 13 Jun 2010 16:49

This post is a continuation of Training to Fail Part 2: Intensity Cycling and High Intensity Overtraining.

Part one of this post showed that it has been very difficult to elicit performance decrements using high intensity overtraining protocols and extreme protocols had to be undertaken to do it. Yet, high intensity in these studies meant MAXIMAL INTENSITIES. What's more these intensities were used over and over, rep after rep, for relatively long periods of time for such training.1 Intensity cycling is used for what is considered relatively high intensities as compared to hypertrophy parameters but nowhere near maximal intensities. The mean intensity of the so-called intermediate 5x5 programs is closer to 80% of maximum and sometimes lower.

5X5 Programs

Imagine yourself doing a 5x5 strength training program. Let's concentrate on the back squat. The goal for the first workout of the week is to get 5 sets of 5 reps on the back squat after adding 5 or so pounds to the bar over what you did the last squat workout. Your goal is to get the reps and sets with that weight. You've been at it for a while and it took you two sessions at the previous weight to barely get the reps and sets in. For this workout you are not sure you can pull it off and you have considered microloading but you don't have small enough weights. So you load up the bar to 225 pounds as last workout was 220. You manage to get two sets of 5. And then one set of 3. And you're done.

The way many would have you proceed at this point would be to reduce the weight back down to perhaps 200 pounds and build back up over several weeks to 225 again in the hopes that you will not only get the 25 reps at that weight but be able to add another 5 pounds or so to the bar. And repeat. This is intensity cycling.

Rote progression models such as this are incredibly asinine and trainees rarely stop to examine the stupidity. If they did they would realize that they reduced the weight even though absolute force production did not go down. In the literature, experts would say that absolute force production, was "preserved." This equates to the muscles' ability to produce tension which equates to, you guessed it, absolute strength. So, you have reduced the weight on the bar as a response to missing reps, even though you have demonstrated the ability to move that weight. You reacted to something that did not happen! If this makes sense to you, then, in my opinion, you are not a logical person.

In the above scenario you did not fail to lift 225 pounds. In fact, you succeeded in lifting it 13 times! So what's the motor skill that failed? How in the world can the correct response to an increase in acute force production be to reduce the weight? You didn't fail to lift the weight you failed to get the WORKLOAD. Workload is the total volume times weight on the bar. And here we're just considering the increasing workload on squats, but in this type of program, workloads are increasing in a similar way pretty much across the board. Given this scenario it is well likely that you could have actually lifted more with lower reps and the proper rest periods. You see, maximum strength tends to be well preserved even in the case of ever mounting workloads like we see on 5x5 programs.

And your goal, remember, is to increase absolute force production. Let's say you get very precious about it and you decide to decrease the weight just because half the reps were slow. Yeah, people do that too. Again..absolute force production hasn't really changed. Just rate of force production on some reps. Due to what? Fatigue. It doesn't matter if it is central fatigue, what matters is that it is the mounting of the workload that is causing fatigue, not the actual load on the bar. See, again, maximal and near maximal abilities are well preserved. It's anaerobic capacity that is suffering.

These intensities are well below the extreme intensities that were necessary to induce performance decrements in the studies that were discussed in Part I of this post. Intensity is only one parameter, however. The frequencies used in the studies were also extreme, having maximal lifts 6 days a week! With no reduction in volume. The typical 5x5 goes nowhere near these extremes and in fact, most strength training programs do not.

Let's look at this another way. Since so much confusion exists because of the different ways of measuring and viewing intensity let's just consider force and work.

F=m(a+g) where:

F = force
m = mass of barbell or other implement
a = instantaneous acceleration
g = acceleration due to gravity (9.81 m/s/s)

Force is measured in units called Newtons.

Work or "mechanical work" is the force applied multiplied by the distance moved.

Let's say the starting weight for the back squat is 100 kgs. That equates to 981 Newtons. Let's say the bar is moved around 1.2 meters per rep. That equates to 1177 joules of work. 1.2 meters multiplied by 25 is 30. So we get around 35, 310 joules in the first session. Since the only thing that changes over time is the mass of the barbell the work goes up as the mass goes up. So the force product goes up. Therefore the total workload goes up over time as the mass of the barbell increases. So, it makes sense that if the only parameter that changes is the mass of the barbell then the mass of the barbell should be the factor we manipulate, right?

Wrong. That doesn't follow at all. The problem is how we measure progress.

Let's do the math again for a second session but change the reps performed to 18 reps.

For this workout, the load on the barbell increases to 102 kgs. So that is around 1000 Newtons. The bar is still moved 1.2 meters per rep but now that equates to 1200 joules. For this session, we fail to make all our reps and only get 18 total reps. So the total work performed is around 21,600 joules. Compared to over 35,000 in our first session. What changed? The mass of the barbell INCREASED. So acute force increased. Only the total distance the barbell was moved decreased. And even if we got 20 or 22 reps we'd still fail miserably in terms of total work. It should be clear, however, that we are quite capable of producing the force needed. We just aren't capable of going the distance. If we look at the force and the work (anaerobic capacity) as two different "motor skills" we see that the total force motor skill tends to be the skill maintained and even apparently improved. It's the "work skill" that suffers.

Of course you can measure mechanical work as I did above, using joules, albeit in a ham-handed way. Or you can simply add up the volume and load increases over time. Either way the increase in workload from week to week with middle-ground strength training programs are HUGE. Frankly, if you have done this type of program before you should be amazed that you can progress in this fashion at all, let alone in such an aggressive way. The shear fact that force production can be maintained and increased over such volumes of work should make my point for me. But even as we keep loading the bar, but subsequently fail to make our reps, we can see that workload plummet from one session to the next.

I have no delusions that the above examples are nothing more than simplistic attempts at biomechanics. But I think simplicity will show the flaws since we are talking about simplistic notions of progress in the first place!

Using Intensity versus the Definition of Failure

I purposely left out intensity notions and instead focused on force production and work. Why? Because it is not clear what definition of intensity is used by proponents of intensity cycling. Furthermore, it is not clear that it even matters. Frequently the intensity is planned based on a trainee's rep maximum (RM). First, we have to define this. The most common way to find a RM is to terminate a set after the final repetition that can be completed with proper form. So the trainee would painstakingly determine how much weight he could manage five good reps with so that the next rep could not be completed without cheating or assistance. If the weight turned out to be 100 pounds then the progression would be determined using percentages of this weight.

The problem is that using intensity to plan a program of progressive overload and using intensity to measure progress are two different things! What so many people don't see is that when we use that what really changes with notions of RM intensity is the definition of failure. When the trainee initially finds his 5RM he is "going to failure" based on one definition of failure. As he progresses, however, he has the choice of several different ways to "fail" and these different ways can constitute a much larger or smaller degree of effort.

Failure Modes

We can assume that most trainees will be using some type of RM failure. In other words, regardless of the degree of difficulty, the trainee will not stop performing reps when another full repetition can be performed. But even so, this leaves the possibility of stopping when another rep cannot be performed with good quality, the RM definition we used above. Or, stopping at the point of "momentary muscular failure" which is when the final attempted rep cannot be completed, or post momentary failure, which may entail a pause after which another rep is completed and this rep may be forced with cheated movements or with the assistance of a spotter. Since most trainees without direct supervision are very inconsistent with the mode of failure they employ they have a very hard time determining when the weight should be increased or maintained. The stated purpose of the program is to provide progressive overload by progressive increases in load past an initial RM. Yet the actual program is performed as if it is a reaction to degree of effort based on the different points at which failure occurs. Although it may be possible to plan continued progression in strength training by recording the types of failure used what we have here is a mixed protocol. The one constant should be the initial mode of failure which is that the repetitions are stopped when another rep cannot be performed with good quality ("proper form").

Since quality is the initial determinant of the RM and since force production does not go down during the training progression but either goes up or is maintained then quality should be the parameter that we seek to maintain while achieving increases in force production. Yes, quality can be regained by decreasing the load on the bar using intensity cycling thereby decreasing the workload. But force production was never in question!

There is a consistent misunderstanding regarding maximal strength training. Most people seem to think that the average load is much higher than it really is. The "median" intensity is actually quite moderate since only one or two exercises might use near-maximal intensities during a week (microcycle) and since the supplemental or cross training exercises follow different parameters depending on their purpose and placement in the week so that the overall intensity used for all exercises taken together is no higher, or even lower, than a typical middle-ground mass/strength program. Although such programs have their place the practice of repeating endless loops via intensity cycling is a complete waste of time and resources. A short volume deload would take the place of several weeks of intensity cycling for most trainees. During such a deload the intensity could be maintained or even slightly increased depending on the extent of the volume reduction. The question of the best way to proceed still remains and this would have to be answered based on the needs of the specific trainee. The problem with such methods, after all, is that they seek to provide "optimal" programming for a wide range of strength trainees.

This page created 13 Jun 2010 16:49
Last updated 23 Mar 2018 23:09

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