Exercise Type: It should be an exercise done as a secondary exercise to follow a mid-range, stretching exercise like stiff-legged deadlifts (for hamstrings mass-building).

Instructions: There are many kinds of leg curl machines. The most common type is pictured. Lie face down on the bench and put your feet behind the pads. The arm of the machine should be adjusted in such a way that allows the weight to stay on the same location at your feet -- right above your heels at the Achilles' tendon. In other words, you don't want the pads to roll up your calf muscle. Adduct your feet -- do not point your toes as you then turn it into a calf exercise. Remember to get a good "squeeze" at the top of the motion. The squeeze should be against the glutes or upper hamstring area. If you are squeezing against the middle of your hamstrings at the top of the motion then you should either slide down further on the machine or adjust the arm out a little longer. When you lower the weight, do so slowly and release it all the way until your legs are almost straight. Do not let the weights in the stack touch!