Can I use a towel instead of a slider disc?

Yes. A folded towel works on hardwood, tile or laminate, and a sock works on very smooth floors. On carpet, use a slider disc made for carpet or a furniture slider, because a towel will not glide.

Can it replace the Nordic hamstring curl?

It can load the hamstrings to a similar level. In a study of 20 resistance-trained adults, a single-leg slider with a slow, three-second slide-out produced peak biceps femoris long head force similar to the Nordic hamstring curl and to full-speed sprinting, and, like the Nordic, it stretched the hamstrings less than nearly every other exercise tested. That makes it a practical option when no partner or anchor is available for a Nordic.

When am I ready to switch from two legs to one?

Move on once you can do 10 to 12 smooth two-leg Sliding Leg Curls with a slow slide-out and the hips staying up. A good bridge between the two is sliding out on one leg and pulling back in with both.

What should the raised leg do?

Keep it lifted with the hip and knee bent and hold it still for the whole set. It should not touch the floor or swing, since either one lets you push or rock the hips up instead of curling with the working leg.

Why do my hamstrings cramp during this exercise?

The hamstring is working hard in a short position, with the knee bent and the hip lifted, which makes cramps common when you are new to the exercise. End the set, stretch gently, and shorten the range or return to the two-leg version until you adapt.

Single-Leg Sliding Leg Curl

What Is the Single-Leg Sliding Leg Curl?

Single-Leg Sliding Leg Curl is an isolation exercise that primarily targets the hamstrings and also engages the glutes, calves and core. It is an advanced-level movement in which you lie on your back with one heel on a towel or slider, lift your hips, and curl that heel toward your glutes while the other leg stays raised off the floor. Nothing more than a smooth floor and a folded towel is needed, so it is a demanding hamstring exercise that needs no gym.

The exercise trains the hamstrings at both of their jobs at once: they bend the knee to pull the heel in, and they help the glutes hold the hips up off the floor. The slow slide back out is where most of the work happens, because the hamstrings have to brake the heel as the knee straightens. That lowering phase is why sliding curls show up in hamstring injury prevention and return-to-sport programs, usually as an accessory after the main lifts of a lower-body session.

The hamstrings carry the load, with the glutes working hard to keep the hips lifted. In a study of 12 healthy adults, hamstring activity exceeded gluteus maximus activity during a one-leg supine sliding bridge, and that slider ranked with banded standing hip extension as the highest hamstring activation of the four exercises tested. Working one leg at a time also makes the gluteus medius and the obliques stop the pelvis from tipping toward the raised leg, and it shows quickly if one hamstring is weaker than the other.

This variation suits trained clients who already handle the two-leg Sliding Leg Curl through its full range with control. If it is too hard, build up with the Glute Bridge and the Single-Leg Glute Bridge, then the two-leg slider curl, then single-leg slide-outs where both feet pull the towel back in. It is often programmed alongside the Nordic Hamstring Curl, another bodyweight hamstring exercise built around a slow lowering phase, which needs a partner or a fixed anchor for the feet.

Muscles Worked

MuscleActivation

Biceps Femoris: Primary
Semimembranosus: Primary
Semitendinosus: Primary
Gluteus Maximus: High
Gastrocnemius (Lateral Head): Medium
Gastrocnemius (Medial Head): Medium
Gluteus Medius: Medium
Adductor Magnus: Low
External Oblique: Low
Rectus Abdominis: Low

Instructions

Fold a towel and place it on a smooth, hard floor, or use a slider disc.
Lie on your back with your arms on the floor by your sides.
Rest the heel of your working leg on the towel with that leg almost straight and your toes pointing up.
Lift your other leg with the hip and knee bent, and keep it raised for the whole set.
Brace your core, squeeze your glutes and press your heel down to lift your hips off the floor. This is the start position.
Dig your heel in and bend your knee, pulling the towel toward your glutes as your hips rise into a straight line from shoulders to knee.
Stop when your knee is bent to about 90 degrees and pause briefly with your hips level.
Slide your heel back out slowly, taking about three seconds, and keep your hips lifted.
Stop just before the knee locks straight, then begin the next rep.
Finish all reps, lower your hips to the floor, and switch legs.

Common Mistakes

Letting the hips drop
Sinking toward the floor as the heel slides out takes load off the hamstring, so keep the hips lifted until the set is finished.
Tipping the pelvis toward the raised leg
When the free side drops or the hips rotate, the working hamstring and glute lose tension, so keep both hip bones level throughout.
Arching the lower back
Pushing the hips up by arching the spine shifts the work from the glutes and hamstrings to the lower back.
Rushing the slide-out
Letting the heel shoot out skips the controlled lowering phase that does most of the hamstring work and raises the risk of a cramp or strain.
Pushing through the toes
Driving with the ball of the foot instead of the heel moves the effort into the calf and makes the towel slip.

Injuries

Single-Leg Sliding Leg Curl is a low risk exercise when performed with proper technique. It uses no external weight and keeps the spine on the floor, but it asks a lot of one hamstring, so the risks come from doing too much too soon rather than from the setup itself.

The most common problems are hamstring cramps and strains when the heel slides out faster than the hamstring can control it, lower-back strain from arching to keep the hips up, and a jolt at the knee when the leg snaps straight at the end of the slide-out. Keep the slide-out slow, hold the ribs down, and stop the heel while the knee is still slightly bent. Expect muscle soreness for a few days after the first sessions; soreness that builds over a day or two is normal, while pain that starts suddenly during a rep is not.

If you cannot keep the hips up for the full set, regress to the two-leg Sliding Leg Curl, shorten the range, or slide out on one leg and pull back in with both. Progress by slowing the slide-out, adding reps, then adding a small weight held on the hip of the working leg.

Stop if you feel sharp pain in the back of the thigh, behind the knee or in the lower back. Anyone returning from a hamstring strain should add single-leg sliding work only when their clinician or physical therapist clears it.

Overview

Primary Focus: Hamstrings
Equipment: Body weight and other
Modality: Strength
Difficulty: Advanced

Alternative Exercises

Other Names for the Single-Leg Sliding Leg Curl

The Single-Leg Sliding Leg Curl is also known as:

Single-Leg Slider Hamstring Curl

Frequently Asked Questions

Q: Can I use a towel instead of a slider disc?: Yes. A folded towel works on hardwood, tile or laminate, and a sock works on very smooth floors. On carpet, use a slider disc made for carpet or a furniture slider, because a towel will not glide.
Q: Can it replace the Nordic hamstring curl?: It can load the hamstrings to a similar level. In a study of 20 resistance-trained adults, a single-leg slider with a slow, three-second slide-out produced peak biceps femoris long head force similar to the Nordic hamstring curl and to full-speed sprinting, and, like the Nordic, it stretched the hamstrings less than nearly every other exercise tested. That makes it a practical option when no partner or anchor is available for a Nordic.
Q: When am I ready to switch from two legs to one?: Move on once you can do 10 to 12 smooth two-leg Sliding Leg Curls with a slow slide-out and the hips staying up. A good bridge between the two is sliding out on one leg and pulling back in with both.
Q: What should the raised leg do?: Keep it lifted with the hip and knee bent and hold it still for the whole set. It should not touch the floor or swing, since either one lets you push or rock the hips up instead of curling with the working leg.
Q: Why do my hamstrings cramp during this exercise?: The hamstring is working hard in a short position, with the knee bent and the hip lifted, which makes cramps common when you are new to the exercise. End the set, stretch gently, and shorten the range or return to the two-leg version until you adapt.