There is more to pushups then just a simple body lift form the floor. Many different push up movements can activate part of the chest muscles that work less during a classic pushup. Here are few push up variations.
1. Smith Rack Push-ups.
Stand in front of a Smith Rack and adjust the bar to a height matching your belly button. Position your hands on the bar just like you are doing classic pushups. Make maximum number of push-ups then lower the bar one level down and continue making push-ups to the max. Do these until you get to floor-level and then finish with classic push-ups. No pauses between changing bar levels.
2. Clap Push-ups.
Position your body on the floor the same as making classic push-ups; then, instead of lifting your body up until elbows are straightened, make an explosive push thus lifting your upper body in the air for a moment, clap your hands as fast as you can, and then return to starting position for another push-up-clap.
3. One Arm Pushup.
Instead of positioning the body on the floor with two hands, place one arm behind your back and the other on the floor. You will notice that to make these push-ups possible, balance must be maintain by spreading the legs, like making a triangle. This is a HARDCORE Push-up, so beginners and intermediates are not advised to make a one-arm-push-up until they overcome several push-up variations.
4. Stretching Push-ups.
These push-ups stretch the chest muscles before every push up. Instead of placing the hands on the floor, place them on two dumbbells in upright position. So when doing a push-up, the body will not be “stopped” by the floor; it will lower enough to stretch the chest and then start another push.