Set yourself up on a glute ham raise machine. The ankle pad should be against your Achilles heel, and your knees should be on the platform supporting your hips. Push the balls of your feet against the foot platform if your machine has one.
With your torso upright, knees bent, and ankles secure, cross your arms in front of your chest, retract your shoulder blades, and inhale.
Slowly extend your legs and bring your torso forward and down while keeping your back and hips rigid.
Descend as much as possible––ideally, until your knees are almost entirely straight.
Engage your posterior chain to bend your knees and raise your torso to the starting position. Exhale near the top.