optimal muscle mass growth ?
i read something that said to achieve optimal hypertrophy you must use training principle such as superset,compound sets, giant sets etc. and only rest 60-90 seconds ! now what i dont uderstand is people say to gain the most muscle mass you must go as heavy as you can for say 6 reps but how can you do this if you're only resting 60-90 seconds and doing a superset ? can someone clear this up for me because im really lost as to how to train for "optimal muscle mass growth" !!!