Harlem Globetrotters tennis ball squats

Tennis Ball Squats: Stand facing a wall, about six feet away. Holding a tennis ball in your right hand, lower yourself into a squat position—feet shoulder-width apart, legs bent to nearly a 90-degree angle. Now throw the tennis ball against the wall with your right hand and catch it with your left. (This may take some practice.) Then throw it back at the wall and catch it with your right hand.