Lying Single Straight Leg Hip Extension
- Target muscle
- —
- Equipment
- Body weight
- Body part
- Thighs
- Type
- Strength
The lying single straight leg hip extension is a bodyweight floor exercise that works one hip at a time, lifting the straight leg back and up behind you to load the glutes and hamstrings. Keeping the knee locked out lengthens the lever arm, so the hamstrings share more of the work than in a bent-knee version. It suits beginners building unilateral glute and hamstring strength, evening out side-to-side differences, and grooving hip extension without loading the spine.
How to do the Lying Single Straight Leg Hip Extension
- 1Lie face down on a mat with both legs extended, hips flat on the floor, and your forehead resting on your stacked forearms.
- 2Brace your core and tuck your pelvis slightly so your lower back stays flat rather than arched.
- 3Keep the working leg completely straight with the knee locked and the foot in a neutral position; leave the other leg relaxed on the mat.
- 4Squeeze the glute of the working side and lift that straight leg toward the ceiling, stopping the moment your pelvis or lower back starts to move — for most people that is roughly 10–20 cm off the floor.
- 5Hold the top position for one count, feeling the contraction in your glute and the back of your thigh.
- 6Lower the leg slowly and with control until it hovers just above the mat; do not let it drop or rest between reps.
- 7Complete all reps on one side, then switch legs and repeat.
Form tips
- Judge the top of the rep by feel, not height: if you feel the lift in your lower back rather than your glute, you have gone past your hip's range — shorten it.
- Keep both hip bones pressed into the mat so the pelvis stays square; letting the working side roll up turns the lift into trunk rotation.
- Keep the knee straight for the whole set — as soon as it bends, the lever shortens and the hamstrings unload.
- Breathe out as you lift the leg and breathe in as you lower it to keep your core braced and your lower back stable.
- Place a folded towel under your hips if lying flat feels uncomfortable on your lower back.
Common mistakes
- Arching the lower back to lift the leg higher — the extra height comes from the lumbar spine, not the hip, which loads the low back instead of the glutes and can cause pain.
- Rolling the pelvis so the working hip lifts off the mat, which lets the trunk do the work and takes tension off the glute you are trying to train.
- Swinging the leg up with momentum instead of a controlled glute squeeze, which bypasses the target muscles and cuts the training stimulus.
- Letting the knee bend on the way up, which shortens the lever and turns a straight-leg hip extension into an easier bent-knee version.
- Resting the leg fully on the floor between reps, which releases tension and shortens the effective time under load — stop just short of the mat instead.
Frequently asked questions
What muscles does the lying single straight leg hip extension work?
It works the glutes and hamstrings of the working leg, which extend the hip to lift the leg behind you. Keeping the knee straight lengthens the lever arm and increases hamstring involvement. The core and low-back muscles work isometrically to keep the pelvis still.
What is the difference between a straight-leg and a bent-knee hip extension?
A straight leg creates a longer lever arm, making the movement harder and sharing the work between the glutes and hamstrings. Bending the knee shortens the lever and biases the glutes with less hamstring involvement.
How high should I lift my leg?
Only as far as your hip will travel with the pelvis flat on the mat — usually a fairly small range. If your lower back arches or your hip rolls up to gain height, you have gone too far and should lower the leg.
How many sets and reps should I do per side?
Three to four sets of 10–15 reps per side is a sensible default. Because it is a bodyweight movement, higher reps (15–20+) with a slow tempo and a pause at the top also work well.
How can I make the lying single straight leg hip extension harder?
Hold the top position longer (3–5 seconds), slow the lowering phase to a 3–4 second count, or add reps — all of which raise time under tension with no equipment. If you want more resistance, an ankle weight on the working leg is the simplest progression.
