Grab a pair of dumbbells, and stand with your feet shoulder-width apart and knees slightly bent. Bend at your hips, keeping your lower back naturally arched (don't round it!), and lower your torso until it's almost parallel to the floor. Let the dumbbells hang at arm's length from your shoulders [A]. Pull the dumbbells to the sides of your torso, by raising your upper arms, bending your elbows and squeezing your shoulder blades together [B]. Pause, then slowly lower the dumbbells back to the starting position.