Push-ups, which require no special equipment, are calisthenics that strengthen and tone the back, chest, arm, and shoulder muscles.
The following modified push-up is ideal for beginners. Start by kneeling with knees hip-width apart. Place your hands on the floor, forward from your knees and directly under your shoulders. Contract your abdominal muscles and straighten your body so that it forms a line from head to knees. Your hands and knees now support your body weight. Arms should be straight but not locked at the elbows.
Lower your torso by slowly bending your elbows. Stop when your elbows are at shoulder level. Push up to the start position without locking elbows. Repeat 8 to 10 times, breathing regularly throughout the exercise.
Beginners should do this modified, knee push-up throughout the set. As you become stronger, perform a full-body push-up. Do this push-up with your weight on your hands and balls of the feet.