Basic Hypertrophy Training the Proper Way: An Overview

Muscular hypertrophy is the physiological process of muscle-fiber enlargement that results from progressive resistance exercise [3]. Hypertrophy occurs when muscle protein synthesis exceeds muscle protein breakdown. This can be achieved with both resistance training and protein ingestion [6]. In other words, protein intake alongside resistance training is a potent stimulus for muscle protein synthesis [6]. Three major factors are emphasized in the conventional hypertrophy model: mechanical tension, metabolic stress, and muscle damage [6]. Progressive mechanical tension overload is considered one of the major factors of muscle growth and changes in muscle architecture, which are attained by increasing resistance training intensity of effort [6]. Resistance training with high-loads (>85% 1RM), and a low number of repetitions (1−5) as well as long rest intervals (3−5 min) is largely oriented toward a greater magnitude of mechanical tension, which primarily develops strength, while muscle hypertrophy is compromised [6]. Implementation of training with moderate number of repetitions (6−12), multiple sets (3−6), moderate loads (60−80% 1RM), and short rest intervals (60 s) between sets elicits greater metabolic stress (in contrast with high-loads), which appears to be a potent stimulus for inducing muscle hypertrophy [6].

General Guidelines

To facilitate muscular hypertrophy, exercise sessions that favor relatively high training volumes and relatively brief rest periods between sets are recommended [3]. A general guideline for hypertrophy training is shown in the table below.

Training Goal       Sets      Repetitions       Rest Interval             Intensity

 Hypertrophy       3-6           6-12            30-90 seconds     70-80% of 1-RM

The American College of Sports Medicine (ACSM) recommends the following:

Experience Level      Sets         Repetitions          Rest Interval            Intensity                  Frequency

 Beginner                  1-3               8-12                 30-90 sec.         70-85% 1-RM        2-3 days/week 

 Intermediate            1-3               8-12                 30-90 sec.         70-85% 1-RM         4 days/week

 Advanced                3-6               1-12              30 sec. - 3 min.     70-100% 1-RM       4-6 days/week

Volume. Training volume has been suggested to be one of the most important variables for muscle hypertrophy, whereby greater training volumes elicit greater increases in muscle size [5]. Higher volume (e.g., 28-30 sets/muscle/week) is associated with greater increases in hypertrophy compared to lower volume (e.g., 6-10 sets/muscle/week) in both untrained and trained individuals [6]. Bodybuilders typically perform 3-6 sets of each exercise and ≥4 different exercises per major muscle group [3]. As a result, each muscle group can be trained for 12-24 sets of 6-12 reps, which constitutes a relatively high-volume training protocol that seems to be especially effective for increasing muscle size [3].

Rest Interval. For most exercises, bodybuilders will rest 30-90 seconds between consecutive sets in an attempt to induce and maintain a muscle pump, which appears to facilitate muscle hypertrophy [3].

Frequency. The most common training frequency for muscular hypertrophy is the split-routine [3]. Most bodybuilding routines feature a six-day split, working one or two major muscle groups during each session [3]. An example of such a split is pushing exercises (i.e., chest, shoulders, and triceps) on Mondays and Thursdays, pulling exercises (i.e., back and biceps) on Tuesdays and Fridays, and trunk and legs on Wednesdays and Saturdays [3]. It is critical to give each muscle group 72 hours of recovery and remodeling time between successive training sets [3]. Working each major muscle group twice a week is an excellent training protocol for enhancing muscle hypertrophy, as it provides two weekly workouts for each muscle group and provides at least 72 hours of recovery-remodeling time between similar training sessions [3]. Accordingly, training a muscle group more than twice per week does not elicit additional hypertrophic benefits [5].

At higher levels of competitive bodybuilding, each body part is trained with very high-volume workouts just one day a week [3]. For example, these athletes may work legs on Mondays, chest on Tuesdays, upper back on Wednesdays, shoulders on Thursdays, arms on Fridays, and trunk on Saturdays [3].

The most commonly cited and recognized recommendations are those provided by the American College of Sports Medicine (ACSM). For novice individuals whose goal is to achieve muscular hypertrophy, the ACSM guidelines recommend a resistance training frequency of 2-3 days per week using a total body routine [5]. For intermediate individuals (i.e., individuals with about 6 months of resistance training experience), a frequency of 4 days per week using an upper/lower body split routine is considered ideal [5]. For advanced individuals, a training frequency of 4-6 days per week is recommended, in which 1-3 muscle groups are trained per session using a split body routine [5].

Intensity. The recommended training intensity for hypertrophy is about 70-80% of maximal resistance (1-RM) [3]. However, several studies have found that training with low loads (i.e., 30-60% of 1-RM) results in similar hypertrophic gains compared to training with moderate and high loads (i.e., >60% of 1-RM) when volitional fatigue (momentary muscle failure) is achieved [6]. Reaching volitional fatigue is not necessary to make significant gains in muscular hypertrophy, especially when training with high loads [6]. In fact, evidence indicates that significant muscle growth occurs when the majority of training sets are performed with approximately 3-4 reps in reserve with moderate to high loads [6].

Exercise Type. Most bodybuilders use a combination of free weights and machines to target all of their muscle groups with an emphasis on isolation exercises [3]. Although bodybuilders perform many multi-muscle exercises, they also attempt to isolate each muscle to intensify the training stimulus and enhance the hypertrophy response [3]. For example, bodybuilders generally perform barbell squats and leg presses to concurrently work the quadriceps, hamstrings, and gluteus maximus muscles against heavy weight loads [3]. However, to train these muscles individually, they typically perform leg extensions (quadriceps), leg curls (hamstrings), hip extensions (gluteus maximus), and hip adductions for the hip adductor muscles and hip abductions for the hip abductor muscles [3].

In addition to free weights and machines, bodybuilders frequently perform a variety of cable exercises for purposes of muscle isolation and intensification [3]. It is not uncommon for bodybuilders to finish a training routine with body-weight exercises such as pull-ups, bar dips, push-ups, and bench dips to fully fatigue the targeted muscles [3]. Lastly, split routine and full-body routine training appear to result in similar increases in upper and lower limb muscle mass [4].

Exercise Order. Current ACSM guidelines recommend performing multiple-joint exercises early in a resistance training session followed by single-joint exercises [1]. The reason for this recommendation is based on the premise that performance of multiple-joint exercises is impaired when the involved muscles are prefatigued by prior single-joint exercises [1]. However, data suggests that both sequences are effective for inducing muscle hypertrophy over a 6-week period of resistance training [1]. Furthermore, there is a possibility of a beneficial hypertrophic effect for performing exercises in a manner that progresses from multiple-joint to single-joint movements [1].

Additional Considerations

One can achieve muscle hypertrophy by giving the right stimulus to a muscle or muscle group alone [2]. However, when muscles are trained with the same stimulus while in an anabolic environment, the hypertrophic response is greater [2]. Studies have shown that the physiological elevation in anabolic hormones, such as growth hormone and testosterone, create an anabolic environment that further stimulates muscle hypertrophy of different muscles [2]. One study conducted by Ronnestad et al. (2011) evaluated the chronic effects of training an arm alone and training the other arm immediately after a leg session in separate days [2, 8]. After performing 5 sets of 10-RM on leg press and 3 sets of knee extension and flexion on a super-set model, individuals had a large increase in cross sectional area, although with the anabolic environment, the arm that trained after the legs, had a greater increase in muscle mass [2]. Madarame et al. (2008) also trained the arms of individuals in two different conditions [2, 7]. Both arms executed 3 sets of 10 reps at 50% of 1-RM on separate days, but one of them was followed by occlusion training for the lower limbs [2]. Only the arm followed by occlusion training increased in cross sectional area [2].

Conclusion

There are a number of factors that determine the rate and extent of skeletal muscle hypertrophy achieved through resistance training. Non-training variables such as genetic background, age, and gender, have been shown to govern the hypertrophic response to a training protocol [3]. Furthermore, it becomes progressively more difficult to increase lean muscle mass as one gains training experience, which emphasizes the importance of periodized cycles within an exercise program [3].

Apart from individual factors, available research suggests that maximal gains in muscle hypertrophy are achieved by training regimens that use a repetition range of 6 to 12 repetitions per set with rest intervals of 60 to 90 seconds between sets [3].

Multiple-set training appears to produce superior hypertrophic results. Of the multiple sets, at least some should be performed to the point of muscular failure [3].

Resistance training should be periodized so that muscle growth culminates in a brief period of higher volume overreaching followed by a taper to allow for optimal gains in muscle tissue [3].

Sources

[1] Avelar, A., Ribeiro, A. S., Nunes, J. P., Schoenfeld, B. J., Papst, R. R., Trindade, M. C., Bottaro, M., & Cyrino, E. S. (2019). Effects of order of resistance training exercises on muscle hypertrophy in young adult men. Applied Physiology, Nutrition & Metabolism, 44(4), 420-424. Effects of order of resistance training exercises on muscle hypertrophy in ...: UMGC Library OneSearch

[2] Bertucci, D. R., & Ferraresi, C. (2016). Strength Training: Methods, Health Benefits and Doping. Nova Science Publishers. https://eds-s-ebscohost-com.ezproxy.umgc.edu/eds/ebookviewer/ebook/bmxlYmtfXzExMzQ0NTZfX0FO0?sid=b5e6955f-8aa1-4fff-906c-5bba28f3d5d2@redis&vid=1&format=EB&rid=1

[3] Bryant, C. X., Jo, S., & Green, D. J. (Eds.). (2014). ACE Personal Trainer Manual (5th ed.). American Council on Exercise.

[4] Evangelista, A. L., Braz, T. V., La Scala Teixeira, C. V., Rica, R. L., Alonso, A. C., Barbosa, W. A., Reis, V. M., Baker, J. S., Schoenfeld, B. J., Bocalini, D. S., & D'andrea Greve, J. M. (2021). Split or full-body workout routine: which is best to increase muscle strength and hypertrophy? Einstein (São Paulo), 19. http://ezproxy.umgc.edu/login?url=https://search.ebscohost.com/login.aspx?direct=true&db=edsdoj&AN=edsdoj.0ebdad8a623c4bab819e9de364dc0051&site=eds-live&scope=site

[5] Grgic, J., Schoenfeld, B. J., & Latella, C. (2019). Resistance training frequency and skeletal muscle hypertrophy: A review of available evidence. Journal of Science & Medicine in Sport, 22(3), 361-370. http://ezproxy.umgc.edu/login?url=https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=134213920&site=eds-live&scope=site

[6] Krzysztofik, M., Wilk, M., Wojdala, G., & Golas, A. (2019). Maximizing Muscle Hypertrophy: A Systematic Review of Advanced Resistance Training Techniques and Methods. International Journal of Environmental Research and Public Health, 16(24). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6950543/

[7] Madarame, H., Neya, M., Ochi, E., Nakazato, K., Sato, Y., & Ishii, N. (2008). Cross-transfer effects of resistance training with blood flow restriction. Medicine and Science in Sports and Exercise, 40(2), 258-263. https://pubmed.ncbi.nlm.nih.gov/18202577/

[8] Rønnestad, B. R., Nygaard, H., & Raastad, T. (2011). Physiological elevation of endogenous hormones results in superior strength training adaptation. European Journal of Applied Physiology, 111(9), 2249-2259. https://pubmed.ncbi.nlm.nih.gov/21327794/