Push ups are one of the best all-around exercises for the upper body. Push ups work the chest, shoulders, triceps and even the abdomen, buttocks and back. They can provide athletes with the explosive power needed for hitting a baseball or blocking opposing players on the football field. But push ups also tear down muscle fibers and need to be limited to a certain number of days per week. This allows the muscles to recover because muscle fibers tear when they are exercised.

Those Who Do Not Lift Weights

If you do mostly calisthenics (free hand exercises) and do not lift weights, you should limit your push ups to 3 to 4 times per week. According to Stew Smith, a former Navy Seal, in his "Top 10 Fitness Questions" list on Military.com, you should do push ups every other day at the most. Two hundred total push ups is a good number of total repetitions to perform. Too many push ups can be hard on your elbows and shoulders, especially if you are over 40. As you get older, you become more susceptible to tendonitis (inflammation in tendons).

Weight Lifters and Push Ups

If you lift weights and perform bench press exercises at least twice a week, do push ups on the days you work on your chest and bench press. Push ups are a good exercise to either warm up for a chest workout or finish one off. If you are warming up with push ups, four sets of as many repetitions as you can do is adequate. You will probably do fewer push ups when you finish your chest workout with push ups because you have already exhausted the muscles at that point. Limiting push ups to twice per week will prevent you from over-training muscles in the chest, shoulders and triceps. If you are eating a high protein diet you should be able to both increase strength and build muscle with two supplement push up workouts per week.

Types of Push Ups

If you are doing many sets and types of push ups (e.g., regular push ups then hands together to work triceps), constantly varying the width of your shoulders to work different muscles, you should limit push ups to 2 to 3 times weekly. You should be able to gauge how many days of rest you need between push up workouts as your muscles will still be aching and stiff if you're overdoing them. Moreover, if you are using push up bars or newer equipment with straps that add resistance to your push up, you should also limit your push ups to 2 to 3 days per week. Another variation of push ups that stretch the chest muscles more is push ups on three chairs (two for hands, one for bracing your feet). Chair push ups should be limited to 2 to 3 times per week as well. (See Reference 2 for examples of more intense routines.)

Source:

"Top 10 Fitness Questions"

"A Good Push Up Workout, Part I"