Key Points of Using Reps to Build Mass Summary
- Subjects increased either weight or reps to build muscle mass over 10 weeks.
- There was no significant difference in strength gains or muscle mass between increasing the weight and repetition progression conditions at the end of 10 weeks.
- You can gain muscle mass by increasing the reps and keeping the same weight. Alternating between periods of heavy and light weight lifting can prevent burnout and improve workout motivation.
Finding the Optimal Rep Range for Using Reps to Build Muscle Mass
Resistance training strategies often focus on manipulating weight, sets, reps, and frequency to enhance muscle hypertrophy or muscle mass. Periodization or gradually increasing the tension on the muscle is important for continually building muscle mass. Studies have found that periodization in resistance training programs can optimize muscle growth by steadily varying the exercise sets and weight, thereby improving muscle adaptation over time. (Moesgaard et al., 2022) Similarly, a 2021 study found that different resistance training modalities could improve muscle quality and elevate muscle growth factors, further supporting the role of structured training variations in achieving significant muscle growth. (Seo et al., 2021)
There are many ways to achieve progressive overload in a workout routine. You can increase the weight, the number of repetitions, or do more sets? Scientists have found that you can build muscle with heavy and light weights unless you have lived under a rock these last few years. (Carvalho et al., 2022) A 2021 literature review found that gains in muscle mass are independent of weight, but strength gains were heavily dependent on the weight used. (Lopez et al., 2021)
While increasing load is a well-known method for enhancing muscle strength and size, the role of increased repetitions, especially at submaximal loads, is equally significant. A 2022 study explored the muscle adaptations from either increasing the weight or increasing the reps. It concluded that progression in reps resulted in similar increases in muscle mass, but increasing the weight resulted in slightly more significant strength gains (+5.9%) than increasing the reps. (Plotkin et al., 2022)
Study Synopsis
A new study conducted by Chaves et al. 2024 compared weight progression and rep progression strategies over 10 weeks on muscle mass and strength gains. The researchers had subjects perform single leg extensions. On one leg, they applied progressive overload by increasing the load, and on the other leg, by increasing the number of reps. The load progression protocol in the study involved starting with 4 sets of 9-12 repetitions maximum (RM) for the leg extension exercise. The load was then increased when failure was reached outside the target rep range. The researchers assessed the leg muscle mass size and strength before and after a 10-week training intervention. They also compared the load lifted (absolute and % of 1RM), the number of reps performed, and the volume load between the conditions.
Results of Increasing Reps or Weight to Build Muscle Mass
Interestingly, the study reported significant increases in both leg extension strength and muscle mass of the legs, with no significant differences between the groups. The subjects achieved similar gains in muscle mass and strength, whether they increased the weight or the reps. The only notable differences were in the specific training parameters: heavier loads were lifted in the load progression group, and more reps were performed in the rep progression group. Despite these differences, the overall impact on muscle and strength development was comparable.
Discussion on Using Reps or Weight to Build Muscle Mass
The findings challenge the traditional emphasis on heavier weights for maximum strength gain. Although previous studies, such as Plotkin et al., suggested slightly greater strength gains (+5.9%) with load progression, the current research by Chaves et al. found only a minimal difference in favor of load progression (+1.4%). This suggests that while increasing the weight is a critical factor in strength training, increasing reps can be equally effective, especially in less trained or novice individuals.
Practical Applications of Using Reps to Build Muscle Mass
The study provides valuable insights for trainers and athletes alike. For those focusing on building muscle mass, incorporating a variety of rep ranges into their routine can be beneficial. Mixing high and low reps ensures comprehensive development across different muscle fibers and can lead to consistent gains in both strength and size. While load progression remains essential for strength-specific goals, it doesn’t always have to be the focus of every session. Alternating focus between load and reps, and even integrating set progression or modifying rest periods, can provide a more adaptable and sustainable approach to training. This flexibility allows athletes to continue making progress without the undue strain of constantly increasing loads, which can lead to overtraining and injury.
Training programs should thus be tailored to the goals and the individual’s fitness level, recovery capacity, and overall training history. Embracing various training methods can help maximize results while minimizing the risk of plateaus and setbacks.
References
Chaves, T. S., Scarpelli, M. C., Bergamasco, J. G. A., Silva, D. G. D., Medalha Junior, R. A., Dias, N. F., Bittencourt, D., Carello Filho, P. C., Angleri, V., Nóbrega, S. R., Roberts, M. D., Ugrinowitsch, C., & Libardi, C. A. (2024). Effects of Resistance Training Overload Progression Protocols on Strength and Muscle Mass. International journal of sports medicine, 10.1055/a-2256-5857. Advance online publication. https://doi.org/10.1055/a-2256-5857
Carvalho, L., Junior, R. M., Barreira, J., Schoenfeld, B. J., Orazem, J., & Barroso, R. (2022). Muscle hypertrophy and strength gains after resistance training with different volume matched loads: a systematic review and meta-analysis. Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme.
Lopez, P., Radaelli, R., Taaffe, D. R., Newton, R. U., Galvão, D. A., Trajano, G. S., Teodoro, J. L., Kraemer, W. J., Häkkinen, K., & Pinto, R. S. (2021). Resistance Training Load Effects on Muscle Hypertrophy and Strength Gain: Systematic Review and Network Meta-analysis. Med Sci Sports Exerc, 53(6), 1206-1216. https://doi.org/10.1249/mss.0000000000002585
Moesgaard, L., Beck, M. M., Christiansen, L., Aagaard, P., & Lundbye-Jensen, J. (2022). Effects of Periodization on Strength and Muscle Hypertrophy in Volume-Equated Resistance Training Programs: A Systematic Review and Meta-analysis. Sports Medicine, 52, 1647 – 1666.
Plotkin, D., Coleman, M., Van Every, D., Maldonado, J., Oberlin, D., Israetel, M., Feather, J., Alto, A., Vigotsky, A. D., & Schoenfeld, B. J. (2022). Progressive overload without progressing load? The effects of load or repetition progression on muscular adaptations. PeerJ, 10, e14142. https://doi.org/10.7717/peerj.14142
Seo, M.-W., Jung, S.-w., Kim, S.-W., Lee, J.-M., Jung, H. C., & Song, J. K. (2021). Effects of 16 Weeks of Resistance Training on Muscle Quality and Muscle Growth Factors in Older Adult Women with Sarcopenia: A Randomized Controlled Trial. International Journal of Environmental Research and Public Health, 18.
