- Lie down on a comfortable surface on your back.
- Extend your legs and create a bend in your knees, let the soles of your feet rest flat on the ground.
- Assume your starting position with your head raised slightly off the ground and your arms extended forward just outside your knees.
- Sit up as fast as you can, so your hands extend past your knees and then return to the starting position as fast as you can – repeat until failure.
- Rather than aiming for constant load on the muscles, complete as many reps as possible within 40 seconds.
- Work quickly until you start to lose your proper form.
- The goal is to work until fatigued.