1. This movement is performed standing with your feet closer than shoulder-width apart. Your legs should be slightly bent at the knees, despite the name of the exercise.
2. Grasp a barbell with an overhand grip. Let the barbell hang in front of you as you stand straight up, tensing your lower back, buttocks and hamstrings.
3. Slowly lower your upper body bending only at the waist, keeping your arms at a 90 degree angle with the floor. Lower yourself until your chest is parallel to the floor and you feel a good stretch in your hamstrings.
4. While flexing your hamstrings, slowly return to the starting position and repeat.

This is one of the best exercises for hamstring development. It is important to keep the focus on the hamstrings while you're performing each repetition. The slight bend in the knees allows you to get a better stretch at the bottom, and it also reduces the risk of injuring your knees when heavy poundages are used.