Seated leg curl

Why it's here

Most hamstring muscles cross both the hip and the knee, so sitting with the hips bent holds them at a longer length while you curl. In a twelve-week MRI trial, each person trained one leg on a seated curl and the other on a lying curl; the seated leg's hamstrings grew about 14%, against about 9% ^[1]. A second trial found a hip-bent curl, with the lowering emphasised, grew the hamstrings more than Nordic curls did ^[2].

The evidence

• Training study Twenty young adults with no structured resistance training in the previous year trained twice a week for twelve weeks, five sets of ten at 70% of their maximum, one leg seated (hips bent to about 90°) and the other lying (about 30°). Hamstring volume rose about 14% in the seated leg and 9% in the lying leg, with the largest gap in the biceps femoris long head (14% against 7%). Strength gains did not differ between legs ^[1].
• Training study Forty-two young men trained for twelve weeks (34 sessions) with either Nordic curls or a weight-stack knee curl done with the hips bent and the lowering phase emphasised, or did not train. The hip-bent curl grew the hamstrings by 18% against 11% for Nordic curls, and the biceps femoris long head by 19% against 5%; the untrained group did not change. That exercise is a close relative of the seated leg curl rather than the standard machine ^[2].

How to do it

1. Set the machine so your knees line up with its pivot, with the thigh pad holding your legs down and the lower pad just above your heels.
2. Curl your heels down and back as far as the machine allows, then return under control until your knees are nearly straight.
3. Don't cut the straight-knee end short — that is where the hamstrings are most stretched in this position, the condition the first trial above found grew them most ^[1].

Stop an exercise that causes significant or unusual pain and have it assessed. This page describes the movement; it is not rehabilitation advice.

Making it harder over time

This is a isolation exercise in the Progressive Overload Calculator, which adds weight in steps of 2%–5% once every set reaches the top of your rep range, and adds reps until then.

Alternatives

• Lying leg curl — The most common hamstring machine. It grew the hamstrings by about 9% in twelve weeks, though the seated version grew them more.
• Nordic hamstring curl — Needs only something to hold your ankles. In trials with groups that did not train, it grew the hamstrings, most of all the semitendinosus.
• Stiff-leg deadlift — A hip hinge with nearly straight knees. In a nine-week randomised trial it grew the hamstrings by about 7%, most of all the semimembranosus.