Primary muscle
legs
Equipment
machine
Adjust the seat so the pad sits just above your heels and the knee joint lines up with the machine pivot. Curl your heels down and back as far as the machine allows. Pause briefly at the fully contracted position, then return under control to a full stretch. The seated version trains the hamstrings in a lengthened position and tends to produce more growth than the lying version. Common mistakes: lifting the hips to gain leverage, and using so much weight that the return phase is uncontrolled.