Lie face down on a leg-curl machine and hook your heels under the roller pad. Your legs should be stretched out straight so that the pads rest on the back of your ankles. Grasp the handles under the bench for support. Remaining flat on the bench, curl your legs up until your hamstrings are fully contracted. Release and lower the weight slowly back to the starting position.

Sitting on a leg press machine, position your feet together against the crosspiece about should-width apart and toes pointed slightly outward. Grasp the handle grips or sides of the seat. Bend your knees and lower the weight as far as possible without changing the position of your hips. Do not lower the weight so far that your hips start to curl up off the seat! Then slowly push the weight back up using your heels, not your toes. Do not lock your knees at the top, but rather take the weight to just before lock.