Tip: What You Don't Know About Hamstring Curls

The leg curl or hamstring curl isn't an exercise that people put much thought into. Just lay down and curl up your legs, right? Well, yes and no. Here's how to avoid injury and build more muscle on this machine:

• This exercise is the cause of a lot of injuries, both in the hams and the lower back. The problem is that many lifters explode the weight up at the beginning. Instead, begin the lift slowly and under control, then gradually accelerate as you go through the range of motion.
• Flex your feet (lift the toes up). This takes the calves out of the movement and forces the hamstrings to do more work.
• Turn the toes in to work more of the inner portion of the hamstring.
• Turn the toes out to work more of the outer portion of the hamstring.
• To do the Gironda leg curl variation, lift the torso off the pad. This will hit what most people call the "glute/ham tie-in" or the upper portion of the hamstrings. This can be very difficult, but it's the ultimate hamstring isolation exercise.