STARTING POSITION:
Lie face down on the machine to bend your legs with the pad behind your ankles (only a few inches above the heels), if is not adjust the machine lever to fit it. Select the appropriate resistance in the weight stack. Keeping the torso on the bench of the machine, ensure your legs are fully stretched under the pad. Grab the side handles of the machine. Contract your pelvic floor and core.
MOVEMENT:
Curl your right leg up as far as possible while you exhale. Hold 1 sec. Return to the starting position with a smooth movement, preventing moving weights from touching the rest of the stack. Repeat the movement for the specified amount of repetitions and then switch sides and repeat with the other leg.
TIPS: The exercise key is quality over quantity. The trick is to perform the exercise using proper form.