The Science of Muscle Hypertrophy

In an exhaustive review of the research literature on muscle hypertrophy, 3 Swedish researchers (Wernbom, Augustsson, and Thomee, 2007), came to the following conclusions about how to optimally train for muscular hypertrophy based on the available science:

Load: 75-80% of one rep max
Volume: 8-10 repetitions, 3-6 sets per muscle group
Rest: 60-90 seconds between sets
Frequency: 2-3 sessions per muscle group per week
Contraction type:  emphasize both the concentric and eccentric part of the lift
Lift speed: 1-2 seconds up, 1-2 seconds down

These simple recommendations are the foundations of all good drug free bodybuilding programs.

Sports Medicine, 2007 37(3), 225-264