The seated leg curl: machine setup and form

The seated leg curl is a hamstring isolation machine used from a seated position, with your hip already bent to roughly a right angle before you curl your heels down and back against resistance. That seated hip position is the main difference from a lying leg curl, and it changes the starting length of your hamstrings slightly, which is why some lifters prefer one machine over the other.

What muscles does the seated leg curl work?

The hamstrings — covered in our leg exercises hub — do almost all the work bending the knee against the machine's resistance, with the calves contributing depending on how your ankle is positioned. Because your hip is already flexed in the seated position, your hamstrings start the movement in a more lengthened position at the hip than in a lying leg curl, which some lifters find changes where they feel the exercise working along the muscle. Like other leg curl variations, this is a true isolation move — it does not train the glutes, since your hips do not extend during the movement.

Seated leg curl benefits

• Comfortable, supported position. Sitting upright can feel more comfortable than lying face down, particularly for people with lower-back sensitivity.
• Direct hamstring isolation. With your hips fixed by the seat and thigh pad, all the effort goes into the hamstrings.
• Easy single-leg option. Most seated leg curl machines make it simple to train one leg at a time to address side-to-side imbalances.
• Simple progressive loading. A weight stack allows small, controlled increases over time.

Seated leg curl proper form

Adjust the seat and back pad on the machine so your knees line up with its pivot point, and set the thigh pad so it holds your legs down firmly without pinching. Lean back against the pad and hold the side handles for stability, rather than gripping and pulling to help move the weight. Curl your heels down and back through a full range of motion, squeezing your hamstrings at the bottom of the curl, then let the pad return slowly rather than allowing it to snap back. Keep your hips flat against the seat throughout — leaning forward or arching to help move the weight is the most common way lifters cheat extra load through the set.

How to program seated leg curls

Use the seated leg curl as an accessory after your main compound squat or hip-hinge lift, once or twice a week, and increase the weight in small steps once every rep feels controlled through a full range. Training one leg at a time occasionally is a simple way to check for and correct any left-right strength difference.

Seated leg curl vs lying leg curl

The lying leg curl is done face down with your hip fully extended, which some lifters feel more through the middle of the hamstring, while the seated version starts from a hip-flexed position that some feel more toward the top of the hamstring near the glute. Neither position is clearly superior for building hamstring size or strength — using whichever machine is available, or rotating between both over time, works well for most people.

Alternatives without a leg curl machine

If a seated leg curl machine is not available, a resistance band looped around a sturdy anchor and your ankle can mimic the same knee-flexion pattern seated in a chair. A glute bridge trains the hamstrings through hip extension rather than knee flexion, which is a different pattern but still a useful hamstring exercise for a home program without machines.

Safety and who should modify it

Set the thigh pad firmly but comfortably, and keep your hips flat against the seat throughout the set rather than arching to move more weight.

Use a weight you can control through the full range of motion without your torso lifting off the pad. Stop if you feel sharp pain behind the knee or in the hamstring itself, and check with a doctor or physiotherapist before this exercise if you have a current hamstring strain or a knee condition that limits bending.