Disclaimer: what was intended to be a diagram and a very brief explanation on BR Physical Performance Facebook quickly turned into an extensive blog following a glass of scotch and a few hours on the NIH libraries.  If you are not interested in the evidence that drives my practice and want to get right to my programming strategy for hypertrophy scroll down to “Organization and Programming of Hypertrophy Training”.

Introduction

Training is the process by which environmental stressors are applied to an organism in a planned and systematic manner to elicit a desired adaptation and ultimately an objective outcome. Programming is the method of organizing and assigning training means to elicit the desired adaptive response, and the outcome measures associated with it. Skeletal muscle hypertrophy is the process whereby satellite cells (stem cells surrounding the muscle) are activated, differentiate, proliferate, and fuse with the muscle fiber spilling their contents inside and donating their nuclei and cellular machinery. Meanwhile – most likely simultaneously – muscle protein synthesis, specifically the fractional rate of contractile proteins, exceeds that of protein degradation and myofibrils increase in size and density.

Overtime, with proper nutrition and programming these adaptations manifest in noticeably larger, more powerful muscles. There are myriad of cellular and molecular factors thought to be responsible for signaling the synthesis of new muscle proteins, and though that is beyond the scope of this article you can read more about it here. Hypertrophy training itself is multifaceted with a number of different variables to be considered, but there are some basic principles that should guide any program design.

In no particular order, these principals are:

• Overload – to activate the molecular pathways responsible for adaptation the stressor applied to system must be greater than what the system has previously adapted to
• Progression – once new adaptations are complete, an increase in the stress must be applied to continue driving adaption
• Specificity – to achieve a specific and predictable adaptation, a specific stressor must be applied

A variety of effective methods exist to meet these principals and achieve muscle growth, but there are several other factors must also be taken into consideration when programming.

Delayed Onset Muscle Soreness

Exercise induced muscle damage and the resultant inflammatory cascade due to high intracellular calcium concentrations and intracellular constituents “leaking” into the extracellular space is thought to sensitive nociceptors (pain) and lead to DOMS. Inflammatory cytokines associated with DOMS may play a role in hypertrophy. In particular, prostaglandin PGF-2α produced by contacting muscle cells has been shown to contribute to hypertrophy both by activating satellite cells and stimulating muscle protein synthesis (2, 9). Interlukin-4 and 6 are inflammatory cytokines secreted in response to muscle cell damage or loading, and have similarly been shown to activate satellite cells and stimulate muscle protein synthesis (11). Despite these signals, the exact role (if any!) (6) of exercise induced muscle damage and DOMS with hypertrophy is still not well understood (21).

The repeated bout effect refers to building a resistance to muscle damage as a result of the protective adaptations that occur following the previous damaging bout. Single sessions that do not cause any muscle damage will lead to a repeated bout effect, but the strongest and longest lasting protections occur following intense training sessions (4,5). Although the repeated bout effect appears to be directly associated with relative training intensity (and likewise muscle damage), significant repeated bout effects still occur with lower training intensities and less muscle damage (5). With this in mind, programming to generate a modest degree of DOMS may be beneficial, however higher levels of muscle damage are not likely to promote a further repeated bout effect, and may even compromise training productivity in future sessions.

Note that 100% intensity causes the greatest decrease and slowest recovery of force output following the first session (left graph).
Notice how 100% intensity creates the greatest protection as seen by the fastest recovery of force output (right graph).
Adapted from Chen et al. 2007.

Training Frequency

Training frequency refers to how often a specific movement quality is trained and is commonly measured weekly. Muscle groups are generally only trained once weekly in the general gym population, and while higher training frequencies seem to promote better strength adaptations, not as much is known in the literature with regards to hypertrophy. Two studies demonstrated similar muscle hypertrophy training each muscle group once or thrice weekly in trained men; however, in one study the volume was not matched with the once-weekly group performing more total repetitions (18), and though volume was matched in the second study it was low (10).

More recently, Schoenfeld et al. (17) compared the differences between once and thrice weekly using a volume-equated, higher volume training schematic.  The results demonstrated greater muscle gains with higher frequency of training, most noticeably in the quadriceps which also happened to be trained first in order all three days of the week.  Given these results and that muscle protein synthesis peaks 24 hr after a bout of resistance training and will remain elevated for up to 48 hours (14) higher training frequencies do appear beneficial. Additionally, it may be possible to accumulate more weekly work with higher training frequencies.

Training Intensity

Training intensity is defined by how close to maximal an individual is working. In strength training, we generally define intensity as a percentage of the 1 Repetition Maximum.  Training intensity guidelines for hypertrophy according to the National Strength and Conditioning Association are 70-85% of the 1 RM (approximately 6-12 repetitions). These guidelines are based partly upon the hormonal response to exercise where high volume training sessions with shorter rest periods generated the largest acute increase in GH and testosterone production (8). While promising in theory, anabolic hormone secretion in response to training appears more responsible for mobilizing fuel for exercise and recovery than providing an anabolic signal for muscle hypertrophy (23: learn more here).  The guidelines of the NSCA are also partly based upon studies investigating acute mTOR pathway activation (a measure of protein synthesis) in response to varying loads (8), but acute increases in protein synthesis are not correlated with hypertrophy (13).

This brings us to longitudinal studies, and fortunately several have been published in the past few years.  Mitchell et al. (12) demonstrated no differences in hypertrophy with 3 sets to failure at 30% 1 RM vs. 3 sets to failure at 80% 1 RM. Another study in untrained women demonstrated no differences in hypertrophy over 10 weeks when load was progressed (from 50% 1RM to 80% 1RM) compared to when volume was progressed (1). Both of these studies were conducted in subjects with no resistance training experience, who more sensitive to loading than trained individuals, and will likely respond to any training load in the begging of a program.

In trained subject one study (3) demonstrated similar hypertrophy of type I, IIA, and IIX muscle fibers in subject training 4 sets of 3-5 RM and 3 sets of 9-11 RM, but not 2 sets of 20-28.  Comparable results have been reported by Schoenfeld et al. (18) in trained men where similar hypertrophy was achieved with 3 RM and 10 RM with comparable volumes. In a follow up study Schoenfeld et al. (16) demonstrated similar results in hypertrophy between 3 sets of 8-12 repetitions compared to 25-35 repetitions. In contrast, Holm et al. (7) demonstrated greater hypertrophy using 70% 1 RM compared to 15.5% 1 RM.

Though the results of these studies appear to contradict each other, one theme appears to stand out. When sets were matched, the lower load training groups accumulated more overall volume and saw greater results. In the studies where total repetitions were matched or comparable, two studies produced better results with higher intensities (3,7) and one study showed no difference (18). Thus, volume appears to be the biggest driver of hypertrophy.

Volume

After reading the previous paragraph, you might still be wondering “if repetitions were the same and higher loads produced more hypertrophy, wouldn’t that mean higher load training is more effective”?  Not necessarily.  Training volume has been defined in a number of different ways, but in its most simple form it can be thought of as the amount of work completed in any given time. In the case of this discussion, volume is defined as the amount of work done per week.

This guy was no stranger to accumulating volume.

Training volume is often quantified as sets x reps, however this equation does not take into consideration load (i.e.: perform 30 reps of curls with 15 lbs. vs. 30 lbs.). Most applicable to hypertrophy-focused resistance training is the total amount of mechanical work, which might be defined as sets x reps x load x time under tension. The TUT variable can be cumbersome to calculate, and is inversely related with the load/reps (i.e.: perform your 5 RM benchpress with a 5-1-5 tempo and see how many reps you can perform!). Though TUT cannot be disregarded in research studies, in practice TUT does not need to be heavily considered  within reason (i.e.: 2-5 s TUT/rep) (15).

In practical applications training volume with regards to hypertrophy outcomes can best be quantified as tonnage.  Tonnage is sets x reps x load.

For example:

• 3 sets x 10 reps x 70 lbs = 2100
• 7 sets x 3 reps x 92 lbs = 1953

There’s a pretty good chance that all three of these strategies will lead to similar hypertrophy adaptations if we tested them in a study. And it’s been done, a recent study compared 2-4 reps vs. 8-12 reps with a similar tonnage in well trained men and found no difference in hypertrophy outcomes after 8 weeks of training (18). A second recent study (16) reported similar improvements in hypertrophy with a 30-50% 1 RM compared to a 70-80% 1 RM, however the [estimated] arbitrary tonnage was approximately 40% greater in the 30-50% 1 RM group.

In Campos et al. (3) the [estimated] arbitrary tonnages per session were 1408, 2100, 2160 for the 3-5, 9-11, and 20-28 repetition groups, respectively.  The 3-5 group and 9-11 group experienced significantly greater hypertrophy compared to the 20-28 repetition group. The results from these studies suggests that there are a wide variety of loads above 50-60% 1 RM that can be employed to optimally stimulate muscle hypertrophy so long as tonnage is matched.

Organization and Programming of Hypertrophy Training

To recap:

• A small degree of DOMS is required for a robust second bout effect and may promote muscle growth, but too much can be detrimental
• The optimal training frequency for muscle growth likely involves training each muscle group once every 2-5 days
• So long as tonnage is similar, any load over 50-60% of 1 RM is optimal for muscle growth

Thus, training for large, progressive degrees of muscular fatigue on a frequent basis with force generated overload will drive muscular hypertrophy.

Putting it all Together

Below is a representative schematic of the progression of these factors over the course of a hypertrophy block followed by an explanation how I program them into the training cycle.

Fatigue refers to both acute and accumulated fatigue.
Relative intensity is defined as how close to maximum you working with a given load  (i.e.: doing 8 reps with a 10 RM is 80% relative intensity).

Induction:

The first phase is generally a single microcycle with lower overall tonnage due to a reduced relative intensity and in some cases a lower set/rep scheme.  The introduction of unfamiliar stimuli (i.e.: new set/rep schemes and/or variations in exercises and movement patterns) is sufficient to cause enough DOMS to stimulate protective adaptations to tolerate the high workloads to come, but not so much that the individual will not be fully recovered for the loading microcycles.

Loading:

The next objective is generate high levels of muscular fatigue.  The loading phase of the block contains several successive microcycles (2-5 weeks, on average) with the goal of progressively increasing then maintaining tonnage at a level that matches the individual’s maximal recovery capabilities. DOMS will be present, though less than the induction phase, and should not have a large negative impact on training ability. Given the direct relationship between tonnage and hypertrophy, the greatest muscle growth is expected to occur during this phase.

Functional Over-Reaching:

Functional over-reaching has been described as the very first stage of over-training syndrome. Training volume exceeds recovery, performance is reduced, and functional systems are shifted from providing resources for muscular adaptation to the higher organ systems. Not much hypertrophy will occur during this phase, but that is OK. The benefit of reaching and enduring a small period of over-reaching (generally 1-2 with a hypertrophy focus) is that with properly planned recovery (i.e.: a deload week or a subsequent induction week) supracompensation ensues (Verkhoshansky, 1988).

Supracompensation is the restoration of systems and qualities above and beyond that previously achieved. This training objective is most notably relevant for peaking neural adaptations (absolute strength and power) for powerlifting, track, or Olympic lifting meets, and rarely used or discussed for hypertrophy specific training.

So why do I use functional over-reaching in the programming of hypertrophy training?

Tonnage.

The individual will enter the next hypertrophy block with enhanced strength. As a result of the supracompensation adaptation, he/she will be able to utilize a larger load for the prescribed training than if he/she had not over-reached. In theory higher tonnages in training will stimulate a greater degree of hypertrophy. In my practice with clients it is effective, and hopefully in the near future someone will test this programming on hypertrophy in a randomized controlled trial.

I’d love to answer any questions you may have or talk about how this programming can work for you. Please go to the Coaching tab and send me a note!

Jason Cholewa, Ph.D, CSCS

Like Big Red Physical Performance on Facebook

Like Dr. Red Performance on Instagram

Follow Dr. Jason Cholewa on Twitter

Connect to Dr. Cholewa on Linked In

References

1. Alegre LM, Aguado X, Rojas-Martín D, Martín-García M, Ara I, Csapo R. Load-controlled moderate and high-intensity resistance training programs provoke similar strength gains in young women. Muscle Nerve. 2014. doi:10.1002/mus.24271.
2. Brewer C, Waddell D. The Role of Prostaglandin F 2α in Skeletal Muscle Regeneration. J Trainology. 2012;1(1):45-52.
3. Campos GER, Luecke TJ, Wendeln HK, et al. Muscular adaptations in response to three different resistance-training regimens: Specificity of repetition maximum training zones. Eur J Appl Physiol. 2002;88(1-2):50-60. doi:10.1007/s00421-002-0681-6.
4. Chen HL, Nosaka K, Chen TC. Muscle damage protection by low-intensity eccentric contractions remains for 2 weeks but not 3 weeks. Eur J Appl Physiol. 2012;112(2):555-565. doi:10.1007/s00421-011-1999-8.
5. Chen TC, Nosaka K, Sacco P. Intensity of eccentric exercise, shift of optimum angle, and the magnitude of repeated-bout effect. J Appl Physiol. 2007;102(3):992-999. doi:10.1152/japplphysiol.00425.2006.
6. Flann KL, LaStayo PC, McClain DA, Hazel M, Lindstedt SL. Muscle damage and muscle remodeling: no pain, no gain? J Exp Biol. 2011;214(Pt 4):674-679. doi:10.1242/jeb.050112.
7. Holm L, Reitelseder S, Pedersen TG, et al. Changes in muscle size and MHC composition in response to resistance exercise with heavy and light loading intensity. J Appl Physiol. 2008;105(5):1454-1461. doi:10.1152/japplphysiol.90538.2008.
8. Loenneke JP. Skeletal Muscle Hypertrophy : How important is Exercise Intensity ? J Trainology. 2012;1:28-31.
9. Markworth JF, Cameron-Smith D. Prostaglandin F2α stimulates PI3K/ERK/mTOR signaling and skeletal myotube hypertrophy. Am J Physiol Cell Physiol. 2011;300(3):C671-C682. doi:10.1152/ajpcell.00549.2009.
10. Mclester, Jr. JR, Bishop P, Guilliams ME. Comparison of 1 Day and 3 Days Per Week of Equal-Volume Resistance Training in Experienced Subjects. J Strength Cond Res. 2000;14(3):273. doi:10.1519/1533-4287(2000)014<0273:CODADP>2.0.CO;2.
11. Meng J, Zou X, Wu R, Zhong R, Zhu D, Zhang Y. Accelerated regeneration of the skeletal muscle in RNF13-knockout mice is mediated by macrophage-secreted IL-4/IL-6. Protein & Cell. 2014.
12. Mitchell CJ, Churchward-Venne TA, West DWD, et al. Resistance exercise load does not determine training-mediated hypertrophic gains in young men. J Appl Physiol. 2012;113(1):71-77. doi:10.1152/japplphysiol.00307.2012.
13. Mitchell CJ, Churchward-Venne TA, Parise G, et al. Acute post-exercise myofibrillar protein synthesis is not correlated with resistance training-induced muscle hypertrophy in young men. PLoS One. 2014;9(2). doi:10.1371/journal.pone.0089431.
14. Phillips SM, Tipton KD, Aarsland A, Wolf SE, Wolfe RR. Mixed muscle protein synthesis and breakdown after resistance exercise in humans. Am J Physiol. 1997;273(1 Pt 1):E99-E107.
15. Schoenfeld BJ, Ogborn DI, Krieger JW. Effect of Repetition Duration During Resistance Training on Muscle Hypertrophy: A Systematic Review and Meta-Analysis. Sports Med. 2015. doi:10.1007/s40279-015-0304-0.
16. Schoenfeld BJ, Peterson MD, Ogborn D, Contreras B, Sonmez GT. Effects of Low- Versus High-Load Resistance Training on Muscle Strength and Hypertrophy in Well-Trained Men. J Strength Cond Res. 2015. doi:10.1519/JSC.0000000000000958.
17. Schoenfeld BJ, Ratamess NA, Peterson MD, Contreras B, Tiryaki-Sonmez G. Influence of Resistance Training Frequency on Muscular Adaptations in Well-Trained Men. J Strength Cond Res. 2015;29(7):1821-1829. doi:10.1519/JSC.0000000000000970.
18. Schoenfeld BJ, Ratamess N a, Peterson MD, Contreras B, Tiryaki-Sonmez G, Alvar B a. Effects of different volume-equated resistance training loading strategies on muscular adaptations in well-trained men. J Strength Cond Res. 2014;28(10):2909-2918. doi:10.1519/JSC.0000000000000480.
19. Schoenfeld BJ, Wilson JM, Lowery RP, Krieger JW. Muscular adaptations in low- versus high-load resistance training: A meta-analysis. Eur J Sport Sci. 2014:1-10. doi:10.1080/17461391.2014.989922.
20. Serrano AL, Baeza-Raja B, Perdiguero E, Jardí M, Muñoz-Cánoves P. Interleukin-6 Is an Essential Regulator of Satellite Cell-Mediated Skeletal Muscle Hypertrophy. Cell Metab. 2008;7(1):33-44. doi:10.1016/j.cmet.2007.11.011.
21. Thiebaud R. Exercise-induced muscle damage: is it detrimental or beneficial. J Trainology. 2012;1:36-44.
22. Verkhoshansky Y. Programming and Organization of Training.; 1988.
23. West DWD, Phillips SM. Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training. Eur J Appl Physiol. 2012;112(7):2693-2702. doi:10.1007/s00421-011-2246-z.