Why it matters

The Leg Curl builds strength and size in your hamstrings. As an isolation movement, it targets those muscles directly to build size and balance.

How to do it

Adjust the seat and any pads so the working joint lines up with the machine’s pivot, set the pin to your working weight, and keep contact with the support pad throughout.
Sit tall with your back supported and both feet flat on the floor.
Set the pad or ankle strap just above your heels with your legs straight.
Take up the slack and start with your knees straight and the resistance under control.
Curl your heels toward your glutes by bending your knees.
Squeeze your hamstrings hard at the top of the curl.
Lower under control until your legs are straight.
Complete all your reps on one side, then repeat with the other, matching the reps on your weaker side.

Sitting takes the legs out of it — keep your torso still and let the target muscle work.
Curl by bending at the knees while keeping your hips still.
Squeeze your hamstrings at the top for a beat.
Lower all the way until your knees are straight each rep.
Feel the back of your thighs work through the rep.

Rocking the torso to start the rep.

This takes work off the target muscle and reduces what you get from the set.

Instead Keep your back against the pad and move only the working joint.
Letting the hips rise or the pelvis tilt to gain more range.

Extra range from the hips means your hamstrings do less of the curl.

Instead Keep your hips pinned down and move only at the knees.
Cutting the curl short of a full hamstring squeeze.

Stopping short leaves the strongest part of the contraction untrained.

Instead Curl your heels as close to your glutes as your range allows.
Lowering too quickly on the way down.

Rushing the lower skips the part of the rep that builds the most control and strength.

Instead Lower under control until your knees are straight.
Letting the weight stack slam down at the bottom.

A slammed stack means gravity did the lowering, not your muscles.

Instead Control the return so the plates settle without banging.

Tempo: Curl with intent and lower for about two counts.
Breathing: Exhale as you curl your heels in, breathe in as you lower.
Range of motion: Move from fully straight knees to a hard hamstring squeeze. Take the hamstrings through its full working range each rep.
Setting up: Adjust the seat and any pads so the working joint lines up with the machine’s pivot, set the pin to your working weight, and keep contact with the support pad throughout.
If you are new to it: Use a light resistance you can curl without your hips lifting.
Once it is easy: Slow the lowering phase to three counts for extra hamstring tension.