You can do push-ups several times a day if you don't work out to fatigue. Muscles respond differently to repeated exercise than to an intense workout. You build strength with frequent, repeated exercise that challenges your muscles but does not lead to fatigue. When you perform high repetitions and work to the point of fatigue, your muscles undergo injury and need time to heal before your next workout. This type of muscle injury and healing builds mass.
Choose Your Objective
If bodybuilding to increase muscle size is your goal, perform push-ups on non-consecutive days, doing as many push-ups during one session as you can without losing proper form. However, if you want to build strength, do no more than half of your maximum number of repetitions during any one session. Do these low-repetition sets as many times a day as you desire, as long as you maintain proper form with each push-up.