Position
Stand with your legs aligned directly under your hips, knees slightly bent, and your feet pointed straight ahead. Hold on to a bar or dumbbell with your arms at a natural width just outside of your thighs. Begin with your body standing in a ready position, shoulders back, and a natural arch in your lower back.

Technique
Start to relax your glutes and hamstrings. Slowly begin to lower your upper body while maintaining spinal positioning and holding a natural arch in your lower back. Continue to lower your upper body until you feel a light stretch in the hamstrings. Hold, then contract your hamstrings and your glutes, and begin pulling your upper body up slowly. Continue to pull your upper body up to the original start position while stabilizing your erector spinae. Hold and squeeze your glutes together. Repeat.