"Jump Training" activates fast-twitch muscle fibers, which we lose over time, says Tom Holland, author of Beat the Gym. "This explosive move is also very cardiovascular and, therefore, burns more calories than traditional squats."
Stand with feet hip-width apart; lower your butt towards the ground until your heels start to lift off the floor -- keep your back flat and eyes straight ahead. Pause briefly and then jump up quickly, fully extending your legs. Land softly on your mid-foot and roll back towards your heels. Start with 10 to 15 jumps.