Calf Press - Leg Press Machine
While sitting a leg press machine, press the weight rack up as if you were going to do a leg press. Lock your knees and slide your feet down so that only the balls of your feet are on the rack and your heels are hanging off. Push with your toes and point the feet like a ballet stance, pushing the rack along with you. Let the rack come back down bringing the toes closer to your body and repeat. Make sure the handles remain in the locked position. If your feet were to slip off the rack and you don't have the handles locked you can be injured. Don't bounce the rack up and down. Use the muscles slowly with control. You can also focus on the inner or outer calves by pointing your toes in or out instead of keeping them straight.