Which muscles are worked out? You use your triceps, shoulders, back, and chest when you do push-ups right. This works out your whole upper body.
Step-by-step: Lay flat on your chest and your stomach on the floor. Put your hands under your shoulders, next to your chest. Push yourself up and lift your chest, torso, and thighs off the floor. Keep your abs tight so that your body is in a straight line. Come back down to the floor slowly.