Sit on the floor with your legs extended in front of you and a paper plate underneath each heel.
Place your arms a few inches behind you with your fingers facing forward, lifting your hips off the ground. This is the starting position.
Pull your heels in toward your body, performing a hamstring curl, sliding the paper plates toward your hips. Your hips should lift up as your heels come closer to your glutes/body. Only go as far in as your body allows while keeping your arms straight and not letting your hips touch the floor.
Pulling your navel in toward your spine to stabilize your core, push both feet out in front of you, straightening your legs back to the starting position. Avoid hunching your shoulders, and keep your hips above the ground throughout the entire movement. This completes one rep.
Perform as many reps as you can in one minute. If this is too difficult, straighten one leg at a time instead of both legs together.