Resistance exercise is the most effective means for increasing muscle size and strength. For muscle gain, a wide spectrum of loading ranges (approximately 40%–85% of 1-repetition maximum) are similarly effective,[1] whereas for strength, heavy loads (≥ 80% of 1-repetition maximum) are superior to lighter loads.[2][3]
About 10–20 sets should be performed per week for muscle gain,[4] whereas muscle strength is effectively built with lower training volumes of about 5–9 sets per week.[5][6]
For both muscle size and strength, a rest interval of at least 3 minutes between sets is best for most exercises.[7] A shorter rest interval of about 60–90 seconds may be employed for single-joint and certain machine-based exercises during muscle gain-oriented workouts.[8]