Before you settle in, get the hip pad position right — it should sit at your hip crease, not higher on your stomach, so you can fold forward freely with your legs locked securely behind you. Cross your arms over your chest or hold them behind your head to start. Lower your torso by hinging at your hips, keeping your back flat rather than rounding through your spine. Go down until you feel a stretch through your hamstrings and glutes, then reverse the movement by squeezing your glutes to bring your torso back up in line with your legs. Don't hyperextend past that point — stopping in a straight line is the top of the rep, not arching further back.