How to do a leg curl
- Seated machine: adjust the backrest so your knees line up with the machine’s pivot, and lower the thigh pad until it holds your thighs firmly down.
- Set the ankle pad so it sits just above your heels, on the lower calf.
- Hold the handles and keep your hips back in the seat (or, on a lying machine, flat on the bench).
- Curl your heels down and back as far as you can, bending your knees fully.
- Pause briefly, then let the pad return slowly until your legs are almost straight.
Cues that help
- "Knees on the pivot": the right setting makes the curl smooth.
- "Heels to your backside": bend the knees as far as the machine allows.
- "Hips stay down": on a lying curl, do not let your hips rise to finish a rep.
- "Slow on the way back": control the stretch at the end.
Common mistakes
- Hips lifting off the bench on the lying curl. It shortens the hamstrings and lets you cheat; use less weight.
- A short range. Curl as far as you can and come back almost to straight.
- Swinging the weight. Momentum takes the work away from the hamstrings.
- The ankle pad on your Achilles tendon. Move it up onto the lower calf.
- Pointing the toes hard. Keep your feet relaxed or pulled up slightly; pointing them makes the calves join in.
Seated or lying?
A 12-week study had 20 adults train one leg on the seated leg curl and the other on the lying (prone) leg curl, with the same sets, reps and relative weight. The hamstrings grew more in the seated leg (+14% against +9% in total volume), mostly in the hamstring muscles that also cross the hip (Maeo et al., 2021).
The likely reason: sitting bends your hips, which stretches those hamstrings further while they work. If your gym has a seated leg curl, it is a good default; the lying curl still works and is a fine choice for variety.
Sets, reps and weight
- For muscle: 2 to 4 sets of 8 to 15 reps, stopping 0 to 2 reps short of failure. The machine makes it safe to go hard.
- Rest 1 to 2 minutes between sets.
- Pair it with a hip hinge like the Romanian deadlift: one trains the hamstrings at the knee, the other at the hip.
- Add weight once you reach the top of your rep range on every set.
Variations and alternatives
- Lying leg curl: on your stomach; shown above to grow the hamstrings a little less than seated, but still effective.
- Single-leg curl: one side at a time.
- Nordic curl: kneel with your ankles held and lower yourself forward slowly. Very hard, needs no machine.
- Swiss ball or slider leg curl: lying on your back, heels curled in. A home option.
- Romanian deadlift: trains the hamstrings at the hip instead of the knee.
Tracking your leg curls
PushBeyond logs the weight and reps of each set and charts the history of the exercise. Its muscle map counts the leg curl for your hamstrings.