A form of exercise that consists of simple movements that are performed without the assistance of weights or equipment. Calisthenics are intended to increase body strength and flexibility while using the weight of the body for resistance.

The push up is a very basic exercise that most are familiar with and I would bet anyone that has ever exercised has tried to tackle.

Assuming a horizontal, face down position the subject uses the arms to raise and lower the body. The body should remain rigid as the subject presses upward until the exerciser has reached a position where the hands and toes are the only points of contact with a smooth line along the legs and back, arms fully extended. Hold for a moment, then slowly lower to starting position without bending torso or knee joints.