In general all excercise can add to your muscle mass. But muscle gains are different for different types of excercise. In weight lifting for bodybuilding. (Musclemen) The growth of muscle is usually tied to using heavier and heavier weights usually in low or medium number of repetitions. Here they exhaust the muscles, damaging at a microscopic level, and the body responds with repairing and adding new muscle to the muscles one has, The other type of training is called cardio or heart training. This is low weights or resistance and many many repetions (reps)usually in sets to exhaustion, this builds stamina, tone and definition to the muscles.