The Right Rep Count!
Ideally, you’re main focus as a pimply high school beanpole is to get a bit muscular. At least, that’s what my goal has been from day one. It really doesn’t change. The quest for mass has seemingly no end as each new year ushers in a flood of new information to sift through. Your status as a burgeoning meat-head can begin RIGHT NOW with this one tidbit of muscle-building gold.
Hitting a set at a 15+ rep count can fine tune your muscular endurance and stimulate minor growth. It functions to improve the metabolic quality of your muscle. Lifting loads that fall under roughly 65% of your 1RM are not substantial enough to make muscles grow (Mcdonagh & Davies, 1984). If you increase the weight and lower the reps, you theoretically initiate a natural pattern of motor unit recruitment that fatigues both slow twitch and fast twitch fibers (Schoenfeld, 2010). The nature of fatigue forces growth.
The intra-muscular environment created by a moderate set between 6 to 12 reps is optimal for growth. With muscle fatigue comes lactic acid build-up (Schoenfeld, 2010). The lactic acid facilitates the release of endogenous anabolic hormones including testosterone and growth hormone (Schoenfeld, 2010). The moderate sets tap into glycolysis which produces lactic acid. Heavy sets function off energy from the phosphocreatine pathway which generates negligible lactic acid (Refsum, 1961).
Lastly, these sets bring about the eternally sought-after PUMP. The glorious feeling of skin-busting muscle swelling. It signals the hydration of the muscle. Blood plasma seeps out of capillaries into the interstitial space creating the “I feel bigger than I actually am” look (Sjogaard, Adams, & Saltin, 1985). It lays the foundation for muscle sparing and muscle growth. Prioritize your goal in the gym. If muscle growth is your game, keep reps and sets medium. Use heavy sets to improve neuromuscular performance and light sets to spike endurance.
Mcdonagh, M. J., & Davies, C. T. (1984). Adaptive response of mammalian skeletal muscle to exercise with high loads. European Journal of Applied Physiology and Occupational Physiology, 52(2), 139–155. doi:10.1007/bf00433384
Schoenfeld, B. J. (2010). The Mechanisms of Muscle Hypertrophy and Their Application to Resistance Training. Journal of Strength and Conditioning Research, 24(10), 2857–2872. doi:10.1519/jsc.0b013e3181e840f3
Refsum, H. E. (1961). Respiratory Response to Acute Exercise in Induced Metabolic Acidosis. Acta Physiologica Scandinavica, 52(1), 32–35. doi:10.1111/j.1748- 1716.1961.tb02196.x
Sjogaard, G., Adams, R. P., & Saltin, B. (1985). Water and ion shifts in skeletal muscle of humans with intense dynamic knee extension. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 248(2). doi:10.1152/ajpregu.1985.248.2.r190