American College of Sports Medicine Position Stand. Resistance Training Prescription for Muscle Function, Hypertrophy, and Physical Performance in Healthy Adults: An Overview of Reviews

PURPOSE: The aim of this overview of reviews was to determine the impact of resistance training (RT) prescription on muscle function and hypertrophy, utilizing evidence synthesis methods. It updates the American College of Sports Medicine 2009 Position Stand, "Progression models in resistance training for healthy adults." DATA SOURCES: Ovid MEDLINE(R) ALL, Ovid Emcare, Ovid Embase, Cochrane Database of Systematic Reviews, EBSCOhost SPORTDiscus, and Web of Science Core Collection current to October 2024. ELIGIBILITY CRITERIA: Eligible systematic reviews synthesized randomized trials of healthy adults (≥18 yr) who completed RT (≥6 wk; range: 6-52 wk), compared with a group that completed no exercise or an alternative RT program, and reported the change in muscle function, size, or physical performance. RESULTS: We synthesized data from 137 systematic reviews (>30,000 participants). Compared with no exercise (control), RT significantly improved muscle strength, size (hypertrophy), power, endurance, contraction velocity, gait speed, balance, and multiple physical function outcomes. Few RT prescription (RTx) variables affected primary adaptations. However, voluntary strength was enhanced by lifting heavier loads (≥80% one-repetition maximum), through a complete range of motion, for 2-3 sets, at the beginning of training sessions, and ≥2 sessions/wk. Muscle hypertrophy was enhanced by higher volumes (≥10 sets/wk) and eccentric overload. Power was enhanced by moderate loads (30%-70% one-repetition maximum), low-to-moderate volume (≤24 repetitions⋅sets), Olympic-style weightlifting, and power RT (fast concentric phase). Power RT enhanced physical function. Training to momentary muscle fatigue, equipment type, exercise complexity, set structure, time under tension, blood flow restriction, and periodization did not consistently impact training outcomes. CONCLUSIONS: Healthy adults should perform progressive RT, with variable prescription consistent with our findings, to improve muscle function, size, and physical performance. Muscle strength, hypertrophy, power, and certain components of physical function can be enhanced by manipulating the RT variables highlighted.