Pushups aren’t bad for you unless you do more than your shoulders can handle. In that case, you could damage your rotator cuff. They also aren’t a complete fitness routine on their own.
Like any form of exercise, pushups put strain on your body. Do too many, or do them incorrectly, and there's a chance that you can hurt yourself.
Be careful not to overdo it. Pushups put strain on the muscles, ligaments, and tendons in your shoulder - if you're doing them correctly, you'll be forcing your shoulder to carry most or all of your body weight. Do too many, and you could exhaust yourself - compromising your form and raising the chance that you'll inadvertently damage a component of your arm or shoulder.
At particular risk is your rotator cuff. That's a segment of your shoulder that's thick with intertwined muscles, tendons, and ligaments. The rotator cuff allows you to move your arm in a whole range of ways. Put too much stress on it and you could rip one of those components. That might land you in physical therapy or the hospital for a long, painful, and repetitive recovery. It'll certainly interfere with your ability to do more pushups.
The number of pushups that you do, therefore, should be appropriate to your age, body weight, and level of fitness. Remember to stretch before and after and to diversify your pushups with other core exercises. These precautions will reduce your risk of injury and help to raise your overall level of fitness.
If you're not comfortable with traditional pushups, there are intermediate exercises you can perform. Try modified versions with your knees on the ground or with your weight resting on the wall to strengthen your core and shoulder muscles to the point where pushups are more viable.
Keep in mind that core exercises like pushups do not by themselves make up a complete fitness routine. At the very least, you'll want to mix in cardio exercises to improve your stamina and some weights to improve your muscle strength.
Possible short-term side effects
- injury (especially to your rotator cuff)
- build core strength
- burn calories
- can be done anywhere
- can be easily modified