7. Leg Sweeps in the Pool You will really feel this move toning and strengthening your waist as you travel backward in the pool or remain stationary. While standing with a straight spine, contract your abs, bring your knees up to your chest, gently straighten your legs in front of you, and open your legs. Squeeze and close your legs, then rotate your hips slightly to the right as you sweep your left leg across to the right. Next, rotate your hips back to center, return your left leg back to center, and then open both legs again to your starting position. Repeat on the opposite side. Do this water exercise for 30 to 60 seconds, and add more time as you strengthen.