Using a squat or barbell rack, set the barbell at shoulder height.
Position yourself so the barbell is resting on your shoulders and you are facing away from the rack.
Stand up to lift the barbell clear of the rack and take a few steps away from the rack.
Position your feet slightly less than shoulder width apart.
Keep your legs straight and bend forward at the hips.
Continue bending forward until you feel a mild stretch in your hamstrings. (Do not try to bend past the mild stretching sensation. As flexibility increases so does the range of motion.) Hold for a count of one.
Return to the starting position by straightening from the hips. Repeat.
Try these other exercises targeting the same primary muscle group: