Second option: If you've never done push-ups and are concerned about doing them properly, try this modified version. Start with your knees on the floor and raise your feet up behind you. Your knees now take the place of your toes, making the exercise much more manageable.
How often should you do it? Push-ups can be done 2 to 3 times per week, depending on your overall program and goals. Doing the same exercise every day hinders gains because muscles don't actually grow or strengthen during exercise, but during the rest and recovery process that follows.
How many repetitions should you do? If the goal is purely to build strength, doing 4 to 6 reps is best. If you can't do that with straight legs, use the knee-based alternative. If you can do many more than six reps, making the exercise tougher (by having someone press down on your back) will keep you in your rep range. Sometimes people aren't strong enough to provide adequate resistance by simply pressing down on a person's back and it's difficult to gauge constant pressure for an entire set.
Solution: Have a qualified person "load" a weight plate or two on to the upper back for increased resistance. This lower-rep range provides the perfect prescription for building up your upper-body strength.
For the beginner, or for general muscular growth and overall fitness, more reps are fine. But 3 to 5 sets are plenty. Doing too many reps (more than 15 or 20) is less effective for building raw strength. If you can do more than 20 reps and can't add resistance, try shortening the time between sets or slowing down the lowering portion of the movement (e.g., count to 10 as you slowly lower your body on each rep).
How you know you're doing it right? In a nutshell, you should feel the intended muscles working. By working we mean the chest muscles should become exhausted as you progress to your target repetition range. Your chest muscles will likely become engorged with blood (the muscle "pump") and will look and feel fuller. You may also feel the chest muscles burning from a buildup of lactic acid.
How NOT to do it: Although the push-up has been around for decades, many people still don't do it correctly. Watch your butt—it shouldn't lie too low, and it mustn't be raised too high.
Who should do this exercise: Anyone who's interested in an exercise that hits a number of muscle groups to build strength in the upper body.
Who should NOT do this exercise: Anyone who suffers from a shoulder impingement. If you have never done the push-up, begin with the modified knee version. If you have lower-back problems, make sure not to arch your lower back.
Most common mistakes: Allowing the torso to drop too low or sticking the butt too high in the air. Doing so will take the emphasis off of the chest muscles. Placing the arms too wide. Using a ballistic jerking movement to cheat-push the body up.
This exercise is for: Almost everyone, as its intensity can be easily customized.
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