Lying Leg Curls
Face down on a machine, ankles under a pad, you bend the knees against resistance. This is the only common movement that trains the hamstrings purely as knee flexors — deadlifts and good mornings load them at the hip instead — which makes it a genuine complement rather than a duplicate.
Own the movement
Set up first, then execute. Every cue below is something you can check on your next set.
Before the first rep
- Set the pad so it sits on the Achilles just above the heel, not up on the calf muscle where it will pinch.
- Line your knee joint up with the machine's pivot. If your kneecap hangs off the end of the bench, slide down.
- Lie flat with your hips pressed into the pad — no daylight under your stomach before the first rep.
- Grip the handles and pull your shoulders down, so your torso has something to anchor against.
- Point your toes straight up or pull them toward your shins; pick one and keep it for the whole set.
Every rep
Breathing & tempo — Exhale as you curl, inhale as you lower. One second up, one second squeezed at the top, three seconds down.
Sets, reps & load
Where to start, and what to change when it stops being hard.
Start at roughly a quarter of what you can leg press for reps — most people land somewhere near 15-25 kg on the stack. The marker for good is finishing a set of 12 with your hips flat on the pad and a three-second lowering on the last rep. Add a plate only when that is true two sessions running.
What goes wrong
The errors that show up most often, and the cue that fixes each one.
Drop two plates and press your pubic bone into the bench for the whole set. If you still lift, hold a light plate on your lower back as feedback, or switch to a seated curl.
Count three seconds down on every rep. Load the weight you can actually control for three seconds, not the weight you can throw up once.
Slide the roller down to just above the heel. Higher up it shortens the lever, inflates the weight you can move, and digs into the calf belly.
Keep it at 8-15 reps. A single-joint knee flexion under near-maximal load is a hamstring strain waiting for a bad day; get your heavy work from hinges.
Why bother
The hamstrings do two jobs: they extend the hip and they flex the knee. Every hinge you own — deadlifts, Romanian deadlifts, good mornings — trains the hip job and leaves the knee job almost untouched, because your knee angle barely changes during a hinge. The lying curl is where the knee job gets loaded.
Lying face down pins your hips into slight extension, which shortens the hamstrings at the top end before the set even starts. That is why you get less range and less strength here than on a seated curl, and why the lift-your-hips cheat is so tempting — arching lets you steal hip extension to finish a rep the knees could not.
Where it fits
Late in a lower-body session, after squats or hinges, in the 8-15 rep range. Two to three sets twice a week covers it. Do not put it before heavy deadlifts — pre-fatigued hamstrings change how you hinge, and not for the better.
If this one isn't it
No kit, too hard, or too easy — here's where to go instead.
Same job, different kit
Start here instead
When this gets easy
Asked and answered
Lying or seated leg curl — which is better?
Seated, if you have to choose one. Sitting puts the hip in flexion, which lengthens the hamstring before the knee bends, and training a muscle under stretch tends to build more of it. The lying version still earns a place: it hits the shortened end that the seated machine skips, so running both across a week is better than arguing about it.
Do I still need leg curls if I deadlift and do Romanian deadlifts?
Yes, if you want complete hamstrings. Hinges load the hamstrings at the hip with the knee held at a near-fixed angle, so the short head of the biceps femoris — which only crosses the knee — gets almost nothing. Two or three sets of curls a week covers a gap your hinges genuinely cannot.
Does pointing my toes change anything?
A little. Pulling the toes toward your shins brings the calf in as a knee flexor and usually lets you move slightly more weight; pointing them away takes the calf out and puts more of the job on the hamstrings. Pick one per set rather than drifting between them mid-set, and do not expect the difference to reshape your legs.
Why do my calves cramp during these?
Because the gastrocnemius crosses the knee and joins in when you curl, especially with the toes pulled up. Point your toes away for a few sets, drop the load, and make sure you are not going into the exercise dehydrated. Persistent cramping usually means the weight is above what the hamstrings can carry alone.