Push ups are specific exercises that you do when working out in a strength training routine. They are also called press ups because that is what you do - press your body up by using your hands. You start the exercise by lying in a prone position face down on the floor and then raise and lower your body using only the strength of your arms. This type of exercise helps to strengthen the pectoral muscles in the chest wall and the triceps, which is the muscle in the upper part of the arm between the elbow and the shoulder Other parts of the body benefit from this exercise as well, such as:

- the deltoids, which is the rounded contour of the shoulder

- the serrratus anterior, which is the muscle along the upper eight ribs on either side of the body

- the coracobrachialis, which are the three muscles that extend the length of the arm

- the midsection of the body.

In a full press up you must bring your legs and back straight off the floor. However, there are variations intended to further strengthen the various muscles. These variations are:

1. Guillotine. This is one of the most difficult variations of the exercise. When you elevate your body so that it is resting on your hands, lower your chest, head and neck so that they are past the plane of your hands. This gives the muscles in your shoulders a full stretch. Then you return to your starting position.

2. Planche. In this exercise, your hands are the only parts of your body that touch the floor. Your legs are elevated in the air, which means your center of gravity must be over your hands. This variation of the exercise requires that you have a high level of strength and balance.

3. Boxer's. This is a variation of the exercise in which you wear boxing gloves on your hands. You have to use your knuckles and do so without bending your wrists. In Tai Kwan Do, this exercise is a common part of the routine, but is done without the gloves. One of the advantages of doing this variation is that because the knuckles are the part of the hand in contact with the floor, it can harden the bone, thicken the skin and reduce the amount of sensitivity to pain that you have in your hands. It does allow you to throw more punches.

Less difficult variations allow you to support your body in some way. In wall press ups, you stand close to a wall and use your hands to push your body away from the wall. To increase the level of difficulty move your feet farther from the wall. You can also reduce the difficulty of the exercise by using the knees instead of your toes when doing it on the floor. In some exercise routines, when you push your body up so that you are resting on your hands you try to clap your hands together and still maintain your balance