Single Leg Squat
Stand with knees slightly bent, holding a five- to eight-pound dumbbell in each hand. Lift right heel slightly off floor so you’re standing on your left leg. Bend left knee, making sure it doesn't go past toes, as you sit back as far as you can comfortably (shown, left). Hold for a count of three; return to starting position. Perform 8 to 12 repetitions, then switch legs.