Hamstrings, Lower Back
Abdominals, Glutes, Core
Set pins in rack at desired bottom height (e.g., torso parallel).
Place bar on pins.
Position self under bar (on back), feet planted.
Set up like good morning start position but at bottom.
Engage core/back. Extend hips/back to lift bar off pins.
Stand/straighten torso.
Slowly lower bar back to pins by hinging hips.
Repeat.