All the bodybuilders seem to think if they work their legs back biceps on Monday and do chest shoulders and triceps on Tuesday, that their legs back and biceps are resting and growing. Wrong! All the energy you used to work your chest on Tuesday could’ve been used to heal your back legs and biceps from Monday. Your body has only so much energy, it is not infinite. It is finite. People do sometimes die of exhaustion! While that’s an extreme example, it does implies you only have so much energy. If you’re always working out and not resting you’re hurting your chances for growth. Also your joints need a break and the recuperative processes that heal sore muscles need a break. Bottom line: for complete healing and growth, take a week off every 3 months!