For machine leg curls, ditch the ego in pursuit of greater gains by doing them with your feet in plantar flexion on the way down. In other words, on the eccentric or lowering phase of the movement, point your toes. This makes it much tougher... and much tougher leads to more muscle growth.
To really ramp it up, attach a band to the machine so that the resistance increases as your raise your legs up, then hold that top position for a second before lowering under control. Don't just drop your legs back down: resist!
Dorian Yates had a big back, but he trained it wrong. You heard me, wrong. At least that's what Scott Abel says. But you know something? After we read this article, Scott convinced us. We're now doing it the Abel way.
Doing this glute-builder in a rack acts as a depth gauge, much like box squats. It keeps your form in check and it makes it easy load and unload plates.