How To Build More Muscle on Leg Day With the Lying Leg Curl — CPT Approved

There’s a recipe for a good leg workout that works every time — pick a squat variation you enjoy, pair it with a hinge like a deadlift or hip thrust, and do a single-leg something. Hit those beats and you’re 90% of the way there.

But what about the accessories; the machine isolation exercises you use to cap off your session and stumble out of the gym with a great pump? When it comes to your posterior chain, you can’t go wrong with the lying leg curl.

In fact, this hamstring isolation exercise, also called a prone leg curl or lying hamstring curl, is all you need.

Here’s how to do it, and why it works so well. 

How To Do Lying Leg Curls With Proper Form

The lying leg curl machine may look a bit wonky, but it’s really rather simple to operate. Most of the legwork (forgive the pun) happens before you even start lifting. Set up the correct way to have you tackling your reps with the right technique.

How to use a leg curl machine: Adjust the station such that the shin pad rests on the back of your ankles. Your knees should be just slightly off the thigh support. Most leg curl attachments also let you calibrate your starting position; the lower the shin pad is, the more hamstring flexibility you need.

How To Do It

• Lay face down on the pads and grab the handles underneath the torso support while placing the backs of your ankles against the shin pad. 
• Curl your hamstrings by pulling your feet against the pad, raising it up until your knee is bent at least 90 degrees. 

Lying Leg Curl Muscles Worked

If you’ve ever found yourself wondering, “What do leg curls work?” fret not. There are two major muscles in your thighs that perform opposite functions: the quadriceps and the hamstrings. Leg curls work your hamstrings, which lie on the backs of your upper legs.

Your hamstrings, or biceps femoris muscles, serve two important functions. During the leg curl, they pull your shins closer to your femurs, the large bones in your thighs. During other hamstring exercises, such as hip hinges where your torso tips over, your hamstrings also help pull your torso upright. To train this large and powerful muscle effectively, you must incorporate exercises that include both functions. 

Lying Leg Curl Benefits

• Easy & Convenient: Leg curl machines are found in just about every big box gym out there, which makes them a viable go-to if you travel frequently. They’re also straightforward to perform and don’t have a steep learning curve. 

• Isolated Stimulation: Compound, or multi-joint, exercises can target your hamstrings just fine. But for maximal muscle growth, you’ll want to isolate these tissues as well. A lying leg curl machine takes other muscles, like your glutes or lower back, out of the equation entirely when compared to seated leg curls.

• Reduces Injury Risk: Some studies have shown that hamstring exercises like the leg curl, where you resist a force trying to open your knee, to be productive in mitigating injury risk. (1)

Lying Leg Curl Alternatives & Substitutes

So, let’s say you don’t have this machine in your gym, but you’re sold on its benefits. You can make do — and make gains — by doing leg curls without the machine just fine. Try out some of these alternatives: 

Seated Leg Curl

Most gyms will have both a lying, or prone, leg curl station, and an upright, or seated leg curl machine. Both exercises work the hammies, but with one key distinction.

Remember: The hamstrings are a biarticular muscle, meaning the tissue crosses more than one joint. This expands its functionality, and also means your torso posture affects how the muscle does its job.

The big idea: Seated leg curls let you bend at the hips, stretching your hammies more than the lying leg curl. You’ll need more flexibility to do this variation. 

Resistance Band Leg Curl

You can tie a resistance band around a stable structure, like the frame of a squat rack, and lie on the floor to perform leg curls as well. Go for this option if you like to work out in a home gym or train in a facility with limited equipment. 

If you want to more closely replicate the design of the station itself, try resting your stomach on an exercise ball. Or consider snagging our Leg Extension Leg Curl Attachment to perform the exercise without taking up any extra space (if you’ve got a compatible weight bench at home).

Nordic Curl

Nordic curls are one of the few exercises out there that allow you to isolate your hammies without any equipment. This bodyweight exercise is deceptively challenging; most people can only perform the negative or lowering portion. 

Regardless, Nordics are a mainstay prehab move in collegiate and professional athletics and are absolutely worth trying. Be prepared to use accommodation, like holding a PVC pipe, wrapping a band around your torso, or pushing yourself back up with your hands. 

Gym Ball Leg Curl

This gym ball leg curl is a simple move, but you'll definetely feel the heat on your backside. All you need is an exercise ball — often found in commercial gyms and rehab facilities — and you're all set to isolate your hamstrings. 

After planting your feet on the ball and lifting your hips and lower back off the ground, try to keep your spine in a straight line through your reps. Also, if you're looking for more of a challenge, try this move unilaterally — working one leg at a time. To do this, lift one leg up into the air while the other leg remains planted on the exercises ball throughout your reps.

Lying Leg Curl Workout

So, you’re sold on lying leg curls. The next step is figuring out how to plug them into your workout routine. The workout below will do just that, while also giving you one heck of a leg day overall. Remember to start everything off with a proper warm up before you dive in.

• Back, Front, or Hack Squat: 3 x 6

• Romanian Deadlift or Good Morning: 3 x 8

• Lunge or Step-Up: 2 x 10 

• Lying Leg Curl: 2 x 15

• Leg Extension: 2 x 15

• Calf Raise: 2 x 20

The Truth About the Lying Leg Curl

No exercise is magic, but the lying leg curl gets pretty close. There aren’t many machines out there that so effectively isolate such a large and powerful muscle. For that reason, plus its practicality and injury prevention perks, it’s more than worth including in your next leg day. 

FAQs

Is the lying leg curl better than the seated leg curl? 

Not necessarily. Both machines work your hamstrings, but in slightly different ways. If you want to be comprehensive with your training, you can periodically rotate back and forth between the two, but either gets the job done just fine.

Is the lying leg curl bad for your knees?

No! That said, you should discuss any hesitations regarding strength training with your doctor before you get started. Beyond that, training your posterior chain is actually one of the best ways to mitigate injury risk and keep your knees strong. 

Do leg curls hit glutes?

No. Isolation exercises, which involve motion at only one joint, almost always work the target muscle and little else. With regard to the lying leg curl, your hips aren’t flexing and straightening, so your glutes have nothing to do. 

Can I do lying leg curls from home?

Yes! With the Leg Extension Leg Curl Attachment, you can set your bench up to tackle hamstring curls and more with plate loaded, banded, or cable resistance. This attachment works with REP®'s BlackWing™ and Nighthawk™ adjustable bench, the AB-5000 flat competition bench, as well as  REP®'s previous model the AB-5100, and is perfect for those with limited space.

What are hamstring curls?

Hamstring curls is just another name for a leg curl — an isolation exercise that targets the hamstrings. From a lying or seated position, the hamstrings are targeted as you flex your knee against resistance.

References

1. Ribeiro-Alvares JB, Marques VB, Vaz MA, Baroni BM. Four Weeks of Nordic Hamstring Exercise Reduce Muscle Injury Risk Factors in Young Adults. J Strength Cond Res. 2018 May;32(5):1254-1262. doi: 10.1519/JSC.0000000000001975. PMID: 28459795.

Jake Dickson holds a B.S. degree in Exercise Science and is a NASM-CPT. As a health & wellness writer, Jake focuses on making fitness practical and accessible for any audience. Off the clock, you can find Jake at the gym or unwinding by the beach.

This article was reviewed by Rosie Borchert, NASM-CPT, for accuracy.