For this exercise, all you need is a single dumbbell or a medicine ball. Stand with your legs a little farther than shoulder-width apart. Take the dumbbell or ball in your hands and lift your arms above your head. Bend your knees slightly and lean your upper body forward (keeping your back straight) and lower the weight between both legs, without letting it touch the floor. Your knees will bend further as you execute the move. Return to the starting position, bringing the weight back above your head. Repeat the same movement, doing two sets of 20 repetitions.