[Bryan Haycock]

Originally Posted by AnimalMass

Bryan, you make this point...” that mechanical load, rather than neuromuscular fatigue is the primary trigger of muscle hypertrophy.”

And for the most part, I agree with you. I think that load/ muscle tension is MORE responsible for growth than damage, especially concerning sarcomere hypertrophy.

I do not make a distinction between any two types of hypertrophy. Research has never indicated that there is two different kinds. I myself, before having done a lot of the research for HST, wrote about Siff and Verkoshansky’s concept of “rational” and “irrational” hypertrophy. They arrived at this concept after observing that the bodybuilders they were aware of were not as strong as their strength athletes, even though the bodybuilders appeared to have more muscle mass. Their only theory for this was that the bodybuilder must not have as much contractile proteins in the tissue, thus the term “sarcoplasmic hypertrophy”.

However, from a physiological standpoint, the ratio of water to protein doesn’t change significantly in hypertrophied fibers.

Much of the confusion about this is my own fault for having widely published those original articles applying principles from the book Super Training to bodybuilding. However, I am not the only one to blame. In the 90s the concept of “cell volumizing” was promoted by Bill Phillips in his magazine Muscle Media 2000. They used research from liver cells showing an actual cell volumizing effect in order to sell supplements they claimed would do the same for muscle cells. However, research has never been able to demonstrate the same anabolic cell volumizing effect and I quote, “The anabolic effects of IGF-1 in skeletal muscle are not caused by increased cell volume. The results differ from those reported previously in liver cells in which the anabolic effects of IGF-1 were associated with cell swelling. The role of changes in cell volume in the regulation of protein metabolism may be different in skeletal muscle than in other tissues.” (JPEN 1998 May-Jun;22(3):115-9)

But for sarcoplasmic hypertrophy to take place, (which is a significant factor concerning hypertrophy) a person would need to occasionally do high volume is terms of sets and reps (ie. 10x10) occasionally.

I agree that the intracellular metabolic effects of doing high reps are facilitative towards hypertrophy. However, I feel it has a much greater influence on the cells metabolic capacity and neural capacity (i.e. performance)

I think the true issue here is that hypertrophy is still something of an enigma, and no one fully understands it. But I do agree that you have set up a very efficient means for helping guys to grow without becoming stagnant.

Thank you. My intentions behind writing about HST has always been to help people who shared common goals with me. J

I might add that hypertrophy really isn’t so much of an enigma though. Recent research has laid out pretty clearly what is happening. An excellent review can be found in “Control of the Size of the Human Muscle Mass. Annu Rev Physiol. 2004 Jan;66:799-828.” You won’t find a detailed map of signaling molecule pathways however. For that you might read “Invited review: intracellular signaling in contracting skeletal muscle. J Appl Physiol. 2002 Jul;93(1):369-83.” A particularly enlightening is a study by Wertman (http://jp.physoc.org/cgi/content/abstract/535/1/155) found here, “Journal of Physiology (2001), 535.1, pp. 155-164”. If you have access, follow up with the list of more recent studies that have cited Wertman’s paper.

There are MANY other studies exploring the molecular signaling pathways associated with skeletal muscle activity/stretch and hypertrophy, far too many to list here. Not only that, but there does come a point where knowing more about the pathways doesn’t bring you any closer to knowing what to do in the gym. Nevertheless, the information is there if one is interested.

I agree completely here. However, I do think it would be beneficial to incorporate periods of loading verses periods of deloading into a hypertrophy program as well. Science has shown that the body responds to periods of heavy loading (loading that can only be sustained for maybe a 2 week period without totally overtraining) and then follow that heavy loading period with a deloading period where specifically volume is dropped (intensity or frequency could be reduced as well - but I'm a fan of reducing volume during periods of deloading.)

I agree, there is plenty of material demonstrating the benefits of periodization and strength gains.

Also, other than reading HST writings, I have never heard of the "repeated bout effect" in other training texts, and wonder if you coined this term yourself? Could you point us to some studies showing that complete rest is needed in order to induce maximum hypertrophy rather than a period of deloading?

I’m not quite sure I understand the question. I did not coin the term Repeated Bout Effect. I coined Strategic Deconditioning (after reading a lot of physical conditioning studies), but not RBE. Some researchers early on called it the “Rapid Training Effect”, but I liked RBE better so I always say that. You can read more about the Repeated Bout Effect here:

1) McHugh MP. Recent advances in the understanding of the repeated bout effect: the
protective effect against muscle damage from a single bout of eccentric exercise. Scand J Med Sci Sports. 2003 Apr;13(2):88-97.
2) Thompson HS, Clarkson PM, Scordilis SP. The repeated bout effect and heat shock proteins: intramuscular HSP27 and HSP70 expression following two bouts of eccentric exercise in humans. Acta Physiol Scand. 2002 Jan;174(1):47-56.
3) Nosaka K, Clarkson PM, McGuiggin ME, Byrne JM. Time course of muscle adaptation after high force eccentric exercise. Eur J Appl Physiol Occup Physiol. 1991;63(1):70-6.
4) Stupka N, Tarnopolsky MA, Yardley NJ, Phillips SM. Cellular adaptation to repeated eccentric exercise-induced muscle damage. J Appl Physiol. 2001 Oct;91(4):1669-78.
5) Saxton JM, Donnelly AE. Light concentric exercise during recovery from exercise-induced muscle damage. Int J Sports Med. 1995 Aug;16(6):347-51.
6) Nosaka K, Sakamoto K, Newton M, Sacco P. The repeated bout effect of reduced-load eccentric exercise on elbow flexor muscle damage. Eur J Appl Physiol. 2001 Jul;85(1-2):34-40.
7) Nosaka K, Sakamoto K, Newton M, Sacco P. How long does the protective effect on eccentric exercise-induced muscle damage last? Med Sci Sports Exerc. 2001 Sep;33(9):1490-5.
8) J Appl Physiol 1990 Aug;69(2):451-5
9) Can J Physiol Pharmacol 2002 Nov;80(11):1045-53
10) Basic Appl Myol. 1995;5(2):139-45.

As far as “complete rest” being necessary for “maximum hypertrophy” I did not say that. I think it is obvious that the best way to apply an opposite stimulus to exercise and/or muscular overload, which triggers the RBE, is to unload the muscle. I find this self evident according to the SAID principle and the hundreds (if not thousands by now) of hind-limb suspension studies and astronautical research on the effects of weightlessness on skeletal muscle’s susceptibility or sensitivity to loading.

Now assuming that the above addresses the question of why I advocate not training at all in order to try to reverse some of the RBE (Repeated Bout Effect), I will address whether it is necessary or not for a person to practice Strategic Deconditioning in order to overcome the effects of the RBE.

Once a person can no longer progressively increase the load he is using to train with, the muscle will soon finish adapting and stop responding (i.e. stop growing) to that load. What choices does a lifter have at that point to use as a substitute for progressive load? I will suggest options:

1) Use eccentric only sets. This will allow a person to use weights that are heavier than he can lift concentrically, thereby extending his ability to progressively increase the load.

Short Coming This often requires a training partner (and a willing training partner at that!). The potential for injury also increases and weight loads increases.

2) Increase volume (i.e. number of sets per sessions per muscle group) thereby increasing Time Under Load (TUL or sometimes called Time Under Tension [TUT]).

Short Coming There comes a point where due to CNS fatigue, strength/endurance limitations, as well as real-world time limitations, a person simply cannot train longer each session. The risk of developing Overuse Injuries also increases with increased training volume.

3) Increase the frequency of loading/training. In other words, train the muscle more frequently by repeating the previous session using the same weight loads.

Short Coming Once again CNS fatigue is the primary limitation. The more extensive the level of fatigue, the longer it takes for voluntary strength output to return to baseline, let alone increase. If voluntary strength decreases, weight loads cannot be maintained. The risk of developing Overuse Injuries also increases with increased training frequency.

4) Change of exercise selection to increase degree stretch. It is well established that most microtrauma occurs in the muscle when eccentric load is applied towards the end of its range of motion. It is possible that, for example, switching from close grip bent over rows, to close grip chins may increase the shear stress in muscle tissue which has previously adapted to a given weight load.

Short Coming There are only so many exercises which you can go to to increase the degree of stretch. Some muscle groups are more easily addressed this way than others. Still, in a short time the muscle will adapt to the new chronically loaded position. In addition, some exercises that place a muscle in a significantly stretched position are anatomically unstable. This will decrease the actual amount of load a person can handle in those extreme positions, thus defeating the purpose.

5) Use testosterone. Testosterone increases satellite cell activity without mechanical loading, thereby allowing a muscle that has grown resistant to exercise induced muscle damage to continue to grow. This offers tremendous advantages beyond anything that can be accomplished by manipulating your training variables. When it comes to hypertrophy, testosterone is the proverbial “magic bullet”.

Short Coming It is illegal to use testosterone without a prescription in most countries. Some level of education is necessary to manage potential side effects.


I feel that a period of eccentric loading to extend the functional period of progressive loading is the best option for most lifters. After that, I propose that an individual strategically decondition the tissue in order that submaximal weight loads will regain their potential to induce hypertrophy. However, there is nothing wrong with trying to take advantage of any other valid option to extend the useful period of progressive loading, nevertheless, these will prove to be only temporary solutions.