works quadriceps, butt, back, abs, calves) Stand with feet shoulder-width apart and toes pointed slightly outward. Reach your arms up toward the ceiling, forming a Y. Keeping arms raised and chest lifted, lower into a squat until your thighs are parallel to the floor (shown at left). Raise yourself up quickly, coming up onto the balls of your feet, then immediately lower into another squat. Do 20 reps. Then do 1 minute of jumping jacks. Trainer tip: While lowering into the squat, push your hips back as if sitting in a chair.