Muscle Building: Isolation Exercise - Leg Curls

Your target zone with leg curls are your hamstrings, also known as your leg biceps. Lie prone (face down) on the bench of a leg curl machine and hook your heels under the support pads. Keeping your body flat against the bench, raise your heels toward your butt until you can’t lift the weight any farther. Lower the weight slowly to the starting position and repeat. Don’t rush through the exercise; feel the hamstrings contracting and stretching as you lift and lower the weight.