Training to Fail Part 2: Intensity Cycling and High Intensity Overtraining

06 Jun 2010 22:43

See part one in this series Training to Fail: The Failurists.

Intensity cycling is basically what it sounds like. Cycling intensity. Specifically it means dialing back intensity (literally weight on the bar) for a period of weeks and then building back up in set increments to your previous load in the hopes that this will enable additional load to be added to the bar in the weeks that follow.1

In simple terms you are supposedly “taking a break” from the hard work, allowing recovery to take place and thus strength gains to continue. That’s the ‘happy’ version of intensity cycling.

In reality intensity cycling is nothing more than running at that proverbial wall, slamming into it, backing up, and slamming into it again.

You may loosen a few bricks from the wall but it is slow and painful progress. Each time you hit the wall, you break yourself down a bit more.

What is the mistake with Intensity Cycling?

Well, for the trainees that this approach is normally recommended for intensity is not the problematic variable. For instance, this approach comes highly recommended for novice strength trainees. When I say “novice” I mean trainees who have NEVER resistance trained before. Many “beginning” strength trainees may have used resistance training before but not in a strength specific way. However their training age would differ greatly from a true novice.

(A big problem with most so-called beginner routines is that there are few true “beginners” to resistance training which undertake these programs)

However novice trainees rarely approach the kind of intensities that would necessitate a reduction in intensity by way of intensity cycling and even more advanced trainees are not sure to find intensity, as a single variable, the cause of “overtraining”. More likely the volume and workload of the training program would be the problem. But these are only two variables that could contribute.

The effects of strength training intensity on overtraining syndrome are the cause of more speculation than almost any other strength training variable. There seems to be an assumption that the effect of intensity of overtraining can be monitored and observed just like the effects of aerobic endurance training or high volume resistance training.

What do we Know about the Effects of Intensity on Overtraining?

The endocrine responses to high intensity resistance training are much different then for high volume training. The steroid hormones and growth hormones are often unaffected and many of the classical overtraining symptoms are missing.1

The adaptation to aerobic endurance activities and anaerobic resistance training activities are quite different. Anaerobic activities are often thought to be more prone to overtraining and higher intensity strength training, especially with resistances approaching 100% of one rep maximum, have been assumed to play a greater role in overtraining than the actual evidence shows. Not only is the assumption that anaerobic training is more prone to overtraining syndromes than aerobic entirely incorrect but there is very little clear-cut data as to how higher intensities affect overtraining and certainly no reason to believe they play a greater role than other parameters.

The problem is that “overtraining” is looked at as if it is a single and easily recognized entity. But just as different modes of training produce different adaptations they also produce different overtraining responses. Most sources of overtraining information are actually studies of endurance training and little can be inferred from endurance training to anaerobic resistance training.

Just as endurance versus resistance training activities2 result in different overtraining responses so do each of several possible variables of resistance training. Dwelling on ONE variable, as does the practice of intensity training is a serious over-site in the design of strength training programs.

Fleck and Kraemer2 name five variables of a strength training protocol which will affect the physiological response: choice of exercise, order of exercise, load or resistance, volume of exercise, and rest between sets. All these variables can be manipulated and how they are manipulated will determine the outcome of the training program including whether overtraining results.

How overtraining itself is defined is another problem and again, there is not a clear-cut way of viewing it. The term is used differently by different physiologists and perhaps the most important thing to remember is, as I pointed out in my short overtraining article ‘overtraining’ and ‘overtraining syndrome’ are not the same thing.

Overtraining syndrome may be viewed as a collection of physiological, psychological, and performance related responses to training. But that still does not leave us with one operational definition of what overtraining is and many have been suggested. For this article we will use the definition adopted by Fry: Any increase in volume or intensity of exercise resulting in long-term performance decrements (several weeks, months, or longer). 1

How does that definition fit with the popular view of maximal intensity strength training? It fits not at all. The popular view consists of such muddy and completely un-verified claims such as “high intensities result in neural fatigue” or “neural burnout’. In fact the most frequent statement made about high intensity strength training is that it will fry your CNS. It is quite amazing to me that people can go around saying such things with a straight face.

There exists no real and usable scientific data of just what this “neural fatigue”, sometimes called central fatigue is supposed to be. Nobody really knows what they are saying when they talk about the CNS being "fryed." Most research into overtraining, even when it is done on resistance training instead of endurance training focuses on increases in training volume. How such sure and dogmatic statements about overtraining are constantly being made about high intensity training, when faced with such a lack of data, is a mystery.

So what does “neural fatigue” say about the actual observable responses to resistance training? What can it say about affects on muscular strength and power? Or motor control and movement quality? Or training related injuries? Or even psychological profiles?

Absolutely nothing. You can only observe the outward manifestations of the training, which is how you respond to it. The fact is that overtraining is an extremely difficult area of study and little assurance can be gained from even those parameters that have been more thoroughly investigated. When it comes to relatively high intensities used for extended periods it may be almost impossible to develop an effective protocol due to the amount of variables that impact performance at these levels of intensity.

Studies that have produced non-transient performance decrements used ridiculously extreme conditions such as six consecutive days of ten relative maximum singles on a “squat simulating machine” with only two minutes of interest rest for two weeks. Besides performance decrements requiring two to eight weeks of rest before resuming normal training the only other notable results were decreases in low velocity isokinetic knee extension strength and high-velocity knee extension strength. Unlike previous studies, which produced these attenuations in low-velocity knee extension strength with no performance decrement observed. Note that knee extension strength is non specific to the actual training modality. This underscores the difficulty in observing meaningful changes due to high intensity resistance training.

This extreme protocol produced overtraining based on our definition yet many of the typical symptoms of overtraining were NOT present, including alteration of sleep patterns, changes in body composition, changes in circulating hormones. Not only were the typical overtraining endocrine responses not seen but total testosterone increased, while cortisol concentrations slightly decreased, the exact opposite of other types of overtraining.

Clearly, diagnosing “high intensity overtraining” would be difficult in a realistic training environment and it seems that maximum strength is well preserved during this type of training in general. But what of the “central nervous system” theory? Were the strength decrements a result of changes in neural drive (termed “central drive”) or maladaptations in the peripheral musculature?

Remember that the only muscular symptom to go by was the aforementioned changes in knee extension strength across varying velocities. Since the femoral nerve serves the quadriceps knee extensor muscles the researchers maximally stimulated the femoral nerve using cutaneous stimulation so that central regulation of force production was bypassed. The same strength decreases were found by stimulating the muscles involuntarily in this way as were found during voluntary knee extension movements. Thus it appears that the maladaptation was due to changes in the peripheral musculature and not due to changes in central neural drive to the muscles.3

Just in case this is not clear, if the changes were due to CNS involvement then directly stimulating the peripheral muscles should have made the strength decrements go away. Furthermore it should be noted that only 1RM strength was affected by the overtraining protocol. Relative muscular endurance was not affected.

The next part in this series will describe just how intensity cycling is typically done and how it relates to all this.

Comments

Bibliography
1. Fry, Andrew C., and Jay R. Hoffman. "Chapter ^: Training Responses and Adaptations of the Endocrine System." Conditioning for Strength and Human Development. Philadelphia: Lippincot Williams & Wilkins, 2008. 119. Print.
2. Fleck, Steven J., and William J. Kraemer. "Chapter 5: Individualizing Exercise Prescriptions." Designing Resistance Training Programs. Champaign, IL: Human Kinetics, 1997. 91-98. Print.
3. Kreider, Richard B., Andrew C. Fry, and Mary Louise. O'Toole. "Chapter 6: The Role of Training Intensity in Resistance Exercise Overtraining and Overreaching." Overtraining in Sport. Champaign, IL: Human Kinetics, 1998. 107-27. Print.


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Last updated 29 May 2013 15:39

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