1. This movement is performed with leg curl machine. There will be many variations at your gym to choose from.
2. Lie down on your stomach on the machine. Lying stretched out straight, place your ankles behind the pads. You may have to adjust the pad so that it fits at your ankles.
3. Remaining flat on the bench, curl your legs up to your buttocks. Be sure to keep your hips flat on the bench and not to raise them. Hold for a few seconds, contract, then slowly lower the weight back down to the starting position.
4. Repeat the movement.

This is a great basic movement for training the back of your thighs and your buttocks, your hamstrings. You must remember to do this exercise very strictly and to get the fullest range of motion possible. Also, be sure to get a good contraction at the top. Good Luck!