Lying Leg Raise

Learn lying leg raise form, how to control the posterior pelvic tilt, protect the lower back, and progress to a full straight-leg raise.

Quick answer: Lie flat with your lower back gently flattened into the floor, keep the legs straight or slightly bent, and lower them only as far as you can control that flattened position before raising them back up.

Bodyweight beginner Core, Hip Flexors

How to Do It

  1. Lie on your back on a mat with your legs extended and your arms resting flat at your sides or tucked lightly under your lower back for feedback.
  2. Gently flatten your lower back toward the floor by tilting the pelvis posteriorly, and hold that position before you move your legs.
  3. Keeping the legs straight (or slightly bent if that is more controllable), raise them together until just before the lower back starts to arch away from the floor.
  4. Pause briefly at the top of your controlled range, then lower the legs slowly, stopping the descent the moment the pelvis starts to tip forward or the back arches.
  5. Stop the set when you can no longer keep the lower back flattened through the full range, rather than continuing to a fixed rep count.

Technique

  1. Treat the lower back's contact with the floor as the main checkpoint; the legs are only allowed to move as far as that contact stays intact.
  2. Use a slower lowering phase than lifting phase so a loss of pelvic control is visible before it becomes a habit.
  3. Keep the neck relaxed and the shoulders down; the work should come from the hips and trunk, not from straining the upper body.

Key Cues

  • Flatten the back first, then move the legs.
  • Lower only as far as the back stays down.
  • Quality over range: a smaller controlled rep beats a longer arched one.

Common Mistakes

  • Lowering the legs all the way to the floor once the pelvis has already tipped forward and the lower back has arched off the mat.
  • Using momentum to throw the legs upward instead of raising them with a controlled hip-flexion action.
  • Holding the breath or bracing so hard that the ribs flare, which makes the pelvic tilt harder to maintain.
  • Chasing a longer range of motion than the trunk can currently control, especially when fatigue increases through the set.
  • Placing the hands under the hips instead of the lower back, which removes useful feedback about pelvic position.

The lying leg raise is a floor-based core exercise that trains controlled hip flexion while the lower back stays in contact with the ground. It is distinct from the hanging leg raise, which uses a bar, a longer lever, and a grip demand. The floor version removes those extra requirements so you can focus on one thing: keeping the pelvis and lower back organised as the legs move.

How to Do a Lying Leg Raise

  1. Set the starting position. Lie on your back on a mat with your legs extended and your arms resting at your sides, or tuck your fingertips lightly under your lower back so you can feel whether it lifts.[1][2][3]
  2. Flatten the back first. Before moving the legs, gently tilt the pelvis so the lower back presses into the floor. This is the checkpoint you will return to throughout the set.[1][2][3]
  3. Raise with control. Lift the legs together, straight or slightly bent, only as far as you can keep the lower back flattened. The moment the back starts to arch away from the floor, you have reached your usable range for that rep.[1][2][3]
  4. Pause and lower slowly. Hold briefly at the top of your controlled range, then lower the legs with a slower tempo than you used to lift them. Stop the descent as soon as the pelvis tips forward or the back lifts.[1][2][3]
  5. Reset between reps. Let the legs settle without letting the lower back arch or the hips rock, then begin the next repetition from the same flattened starting position.[1][2][3]

Posterior Pelvic Tilt: The Core Control Checkpoint

The single most useful skill in a lying leg raise is not how high the legs travel; it is whether the pelvis and lower back stay organised while they do. A posterior pelvic tilt (gently flattening the lower back into the floor) is the checkpoint that tells you whether the trunk, rather than momentum, is controlling the movement.

Use these checkpoints during a set:[1][2][3]

  • Before you move: Can you flatten the lower back and hold that position for a moment before the legs start moving? If not, the starting brace needs work before you add leg movement.[1][2][3]
  • On the way down: Does the back stay flat as the legs lower, or does it lift the moment the legs pass a certain height? That height is your current controlled range, not a limitation to fight through.[1][2][3]
  • At the bottom: If your goal is to lower the legs close to the floor, only go as low as the flattened position allows. A shorter range with a flat back is more useful practice than a full-range rep with an arched lower back.[1][2][3]

This distinction matters because two people can look like they are doing “the same” leg raise while one is training controlled hip flexion and the other is repeatedly loading an unsupported lumbar extension. The visible range is not the target; the maintained pelvic position is.

Bent-Knee to Straight-Leg Progression Ladder

Build the movement in stages rather than starting with a full straight-leg range.[1][2][3]

  1. Bent-knee lying leg raise: Bend the knees to about 90 degrees and raise the thighs toward the chest, keeping the lower back flat throughout. The shorter lever reduces the demand while you learn the pelvic-control checkpoint.[1][2][3]
  2. Single-leg lying leg raise: Keep one foot flat on the floor for support and raise the other leg, straight or bent, through a controlled range. Switch sides after each set.[1][2][3]
  3. Partial straight-leg raise: Extend both legs and raise them through a smaller range that keeps the back flat, rather than trying to reach full extension immediately.[1][2][3]
  4. Full lying leg raise: Use the longest range you can control with both legs straight, adding a pause at the top before considering more repetitions or a slower tempo.[1][2][3]
  5. Hanging leg raise: Once the floor version is fully controlled, the hanging leg raise is a logical next step that adds a longer lever and a grip demand.[1][2][3]

Stay at each stage until the flattened-back checkpoint holds for every repetition in the set, not just the first few.[1][2][3]

Muscles Worked and Programming

The hip flexors do most of the work of lifting the thighs, while the abdominal and other trunk muscles are responsible for keeping the pelvis and lower back from tipping forward as the legs move. These roles work together rather than in isolation: strong hip flexors without adequate trunk control usually shows up as an arched lower back partway through the range.

For a general strength and control focus, 3-4 sets of 6-10 controlled repetitions is a reasonable starting point. For muscular endurance or higher-volume core work, 2-3 sets of 12-20 quality repetitions can work well once the movement is consistent. Leave the set before the flattened-back checkpoint fails, rather than continuing until the legs simply cannot move any higher.

Pair the lying leg raise with the core exercise hub to compare it against planks, dead bugs, and cable-based options, or use the home ab workout to see how a floor-based hip-flexion exercise fits alongside anti-extension and anti-rotation work.[1][2][3]

Common Mistakes and Alternatives

The most common mistake is lowering the legs to a fixed target, such as touching the floor, regardless of what the lower back is doing. Other frequent errors include using momentum to fling the legs upward, holding the breath so tightly that the ribs flare and the pelvis loses its position, and placing the hands under the hips instead of the lower back where the feedback is most useful.

If the flattened-back position is difficult to find or hold, use the dead bug to practise trunk control with reciprocal limb movement, or a plank to build isometric bracing before returning to the leg raise. Stop if you feel sharp or unusual pain, and seek qualified clinical advice for persistent symptoms or questions about whether this exercise suits you.

Regressions

  • Bent-knee lying leg raise: Bending the knees shortens the lever and reduces the demand on pelvic control while you learn the flattened-back position.
  • Single-leg lying leg raise: Keeping one foot on the floor for support while raising the other leg reduces the load on the trunk and pelvis.
  • Dead bug: Use this option to practise keeping the ribs and pelvis controlled during limb movement before adding the two-leg raise.

Progressions

  • Bent-knee to straight-leg ladder: Move from a bent-knee raise to a partial straight-leg raise, then a full-range straight-leg raise as each stage stays controlled.
  • Paused lying leg raise: Add a brief pause near the top and bottom of the controlled range before adding repetitions or a slower tempo.
  • Hanging leg raise: Progress to the hanging variation once the floor version is fully controlled and you want a longer lever with a grip demand.

Alternatives

  • Hanging leg raise: Choose the hanging version when you want a longer lever and added grip and shoulder demand rather than a floor-supported movement.
  • Dead bug: Use the dead bug when you want an anti-extension core exercise with reciprocal arm and leg movement instead of a two-leg raise.
  • Plank: Use a plank when the goal is isometric bracing rather than a repeated hip-flexion movement.

References

  1. National Strength and Conditioning Association. Anaerobic and Muscle Endurance Development: Lifting Guidelines. National Strength and Conditioning Association (2017)Back to claim
  2. Brad S Currier, Alysha C D'Souza, Maria A Fiatarone Singh, Caroline V Lowisz, Eric S Rawson, Brad J Schoenfeld, Abbie E Smith-Ryan, Jeremy P Steen, Gwendolyn A Thomas, N Travis Triplett, Tyrone A Washington, Timothy J Werner, Stuart M Phillips. American College of Sports Medicine Position Stand. Resistance Training Prescription for Muscle Function, Hypertrophy, and Physical Performance in Healthy Adults: An Overview of Reviews. Medicine & Science in Sports & Exercise (2026)Back to claim
  3. Deborah Riebe, Barry A Franklin, Paul D Thompson, Carol E Garber, George P Whitfield, Melissa Magal, Linda S Pescatello. Updating ACSM's Recommendations for Exercise Preparticipation Health Screening. Medicine & Science in Sports & Exercise (2015)Back to claim
  4. American College of Sports Medicine. ACSM’s Guidelines for Exercise Testing and Prescription. Wolters Kluwer / American College of Sports Medicine (2021)Back to claim
  5. Brad J Schoenfeld, Jozo Grgic, Dan Ogborn, James W Krieger. Strength and Hypertrophy Adaptations Between Low- versus High-Load Resistance Training: A Systematic Review and Meta-analysis. Journal of Strength and Conditioning Research (2017)Back to claim
  6. Brad S Currier, Alysha D’Souza, Maria A Fiatarone Singh. American College of Sports Medicine Position Stand. Resistance Training Prescription for Muscle Function, Hypertrophy, and Physical Performance in Healthy Adults: An Overview of Reviews. Medicine & Science in Sports & Exercise (2026)Back to claim

See our exercise methodology for how this evidence is applied and its limits.

Frequently Asked Questions

What is the difference between a lying leg raise and a hanging leg raise?
A lying leg raise is performed on the floor, where the surface supports the trunk and gives direct feedback through the lower back. A hanging leg raise is performed from a bar, using a longer lever and adding a grip and shoulder demand. The floor version is usually the more approachable starting point, and the two are complementary rather than interchangeable.
How do I stop my lower back from arching during leg raises?
Flatten the lower back into the floor before you start moving the legs, and only lower them as far as that flattened position holds. If the back lifts away from the mat, the range was too large for your current control; use a bent-knee version or a smaller range until the flattened position can be maintained through the full set.
Are leg raises bad for the lower back?
Leg raises are not inherently harmful, but lowering the legs beyond the point where the pelvis and lower back stay controlled can load the spine in a position it is not ready for. Use the range you can control, stop if you feel sharp or unusual pain, and seek qualified clinical advice for persistent symptoms or questions about whether this exercise suits you.
How many leg raises should a beginner do?
Start with 2-3 sets of a bent-knee or single-leg regression, focusing on keeping the lower back flattened through the whole set rather than reaching a specific number. Add repetitions or move to a straight-leg version only once the controlled range feels consistent across every rep.