We have all heard of the muscle confusion principle. It states that exercises need to be changed annualy because our muscles adapt to the current exercises and reach their plateua. But i dont think this is necesarry. I think that an individual can go to the gym everyday and do the same exercises, and still have muscle growth. All that is needed and changed in reps and amount of weight. For instance....monday is light workout so you do 2 sets of 15 lower weight, then wednesday, medium workout with 3 sets of 10 moderate to heavy weight, then on friday is heavy workout with 4 sets of 6 heavy weight. Consequently, muscles are gradually being pressured by an increase in weight.