How to Do Lying Leg Raises: Proper Form & Modifications

Lying leg raises are a bodyweight exercise performed on your back. You lift and lower both legs while your abdominal muscles help keep your pelvis and torso controlled.

The movement mainly involves hip flexion, so your hip flexors do much of the work. Your abdominal muscles create the important stability challenge by limiting unwanted movement through your pelvis and lower back.

Straight legs and a low bottom position make the exercise much harder. You do not need to lower your feet close to the floor for a repetition to count.

This guide explains how to do lying leg raises with proper form, count each repetition and make the exercise easier with bent knees, a smaller range or one leg at a time.

Written by Eric Mathura, B.Sc. Kinesiology and CSEP-CPT, with more than 10 years of experience as a personal trainer and group fitness instructor. Updated August 19, 2026.

Watch: How to Do Lying Leg Raises

Table of Contents

• What Are Lying Leg Raises?
• How to Do Lying Leg Raises
• How to Count Repetitions
• Range, Back Position and Breathing
• Muscles Worked
• Benefits
• Bent-Knee and Reduced-Range Modifications
• Variations and Progressions
• Common Mistakes
• Group Coaching Tips
• Lying Leg Raises in BoardGains
• Frequently Asked Questions

What Are Lying Leg Raises?

A lying leg raise begins with your back supported by the floor. You raise both legs toward the ceiling and lower them while keeping your pelvis and torso steady.

The exercise becomes harder as:

• Your legs become straighter.
• Your legs move farther away from your torso.
• Your feet lower closer to the floor.
• The lowering phase becomes slower.
• Your arms provide less support.

The goal is not to lower your feet as far as possible. Your lowest useful position is the point where you can still control your pelvis, ribs and lower back without pain.

How to Do Lying Leg Raises With Proper Form

1. Lie on your back on a mat or comfortable floor.
2. Extend your legs and bring them close together.
3. Place your arms beside your body with your palms facing down.
4. Gently brace your abdominal muscles.
5. Keep your head, neck and shoulders relaxed on the floor.
6. Raise both legs toward the ceiling with control.
7. Stop when your legs are close to vertical or when you reach a comfortable position.
8. Slowly lower your legs without letting them drop.
9. Stop lowering as soon as your pelvis shifts or your lower back begins to lift or arch.
10. Raise your legs again and continue for the required repetitions.

A slight bend in your knees is fine. Do not force your legs to remain perfectly straight.

How to Count Lying Leg-Raise Repetitions

Raising both legs and lowering them to your controlled bottom position equals one repetition.

1. Begin with your legs raised.
2. Lower them through a controlled range.
3. Raise both legs back toward the ceiling.
4. Count one rep when the lift and lower are complete.

Your legs do not need to touch the floor. The bottom position can be different for each participant and may become higher as fatigue builds.

During BoardGains, complete the number shown on the board. Bent-knee repetitions and controlled reduced-range repetitions still count.

Lying Leg-Raise Form Tips

How Low Should You Lower Your Legs?

Lower only as far as you can while keeping your pelvis and lower back controlled.

One person may lower their legs until the heels are close to the floor. Another may need to stop with the legs at a much higher angle. Both can be correct.

Stop the lowering phase if:

• Your lower back begins to lift or arch more.
• Your ribs flare upward.
• Your pelvis shifts suddenly.
• You feel pressure or pain in your lower back.
• You begin holding your breath.
• Your legs drop instead of lowering smoothly.

Should You Press Your Lower Back Into the Floor?

The goal is to maintain control rather than allowing your back to arch more as the legs lower. A helpful cue is to bring your ribs gently toward your hips and keep your back supported by the mat.

Do not press so hard that you create pain or excessive tension. If you cannot hold the position, bend your knees or reduce the range instead of forcing it.

Where Should You Put Your Hands?

Start with your arms beside your body. Pressing your palms lightly into the floor can provide extra stability.

Placing your hands underneath your hips or glutes may make the movement feel easier, but it should not be used to force your legs through a range you cannot control.

Do not place your hands behind your head or pull on your neck.

Should Your Knees Be Locked?

No. Keep your legs long without forcing your knees into a hard lock. A small bend is acceptable and can reduce tension behind the knees.

The straighter the legs, the longer the lever and the more difficult the movement becomes. Bend your knees more when you need an easier version.

How Should You Breathe?

Use steady breathing instead of holding your breath. You can exhale while lifting and inhale during the controlled lower.

Some people prefer to exhale slowly through the hardest part of the lowering phase. The exact pattern matters less than continuing to breathe while your torso stays controlled.

What Muscles Do Lying Leg Raises Work?

Hip Flexors

The hip flexors lift your thighs toward your torso. This group includes the iliopsoas and the rectus femoris.

Rectus Abdominis

The rectus abdominis helps control the pelvis and limit unwanted arching through the lower back while the legs move.

Obliques and Deeper Abdominal Muscles

The internal and external obliques assist with trunk and pelvic stability. Deeper abdominal muscles also contribute to bracing and control.

Quadriceps

The quadriceps help keep the knees extended during the straight-leg version.

Lying leg raises are often called a “lower-ab exercise,” but the rectus abdominis is one continuous muscle. The movement does not isolate a separate lower-ab muscle, and the hip flexors remain major contributors.

Benefits of Lying Leg Raises

Challenges Core Control

The abdominal muscles work to keep your pelvis and torso steady while the weight of your legs moves away from your body.

Trains Hip Flexion

The hip flexors raise the legs and control their position during the lowering phase.

Requires No Equipment

You need only enough space to lie down. An exercise mat can make the position more comfortable.

Offers Clear Progressions

You can change the difficulty by bending your knees, adjusting the range, alternating legs or slowing the movement.

Works Well in Circuits

Lying leg raises can be used as a floor-based core station in bodyweight workouts, PE classes and group fitness games.

Makes Rep Counting Simple

One controlled lift and lower equals one repetition, so coaches can organize the exercise by reps or time.

Lying leg raises can support hip-flexion strength and trunk control, but they cannot remove fat from one area, create visible abs on their own or treat lower-back pain.

Lying Leg-Raise Modifications

Modification 1: Bent-Knee Leg Raise

Bending the knees shortens the lever and makes the exercise easier to control.

1. Lie on your back with your knees bent and feet on the floor.
2. Place your arms beside your body.
3. Brace your abdominal muscles.
4. Lift both feet and bring your knees toward your torso.
5. Keep your knees bent throughout the movement.
6. Slowly lower your feet toward the floor.
7. Touch down lightly or stop before contact.
8. Raise your knees again.

Lifting and lowering both bent legs equals one modified repetition. Avoid pulling your knees so far toward your chest that your hips roll sharply off the floor.

Modification 2: Reduced-Range Leg Raise

Begin with your legs raised and lower them only a short distance before lifting again. Your controlled range may be small, especially near the end of a set.

Modification 3: Single-Leg Raise

Keep one foot supported on the floor while raising and lowering the other leg. Complete the required reps, then switch sides.

Modification 4: Alternating Heel Taps

Start with your hips and knees bent to approximately 90 degrees. Lower one heel toward the floor, return it and switch sides. Each heel tap can count as one rep.

Lying Leg-Raise Variations and Progressions

Slow Leg Raise

Take three to five seconds to lower your legs. Avoid letting them fall toward the floor.

Paused Leg Raise

Pause briefly at the lowest position you can control, then lift your legs without using momentum.

Alternating Leg Raise

Keep both feet off the floor and alternate raising one leg while lowering the other. This creates a continuous trunk-control challenge.

Flutter Kicks

Hold both legs off the floor and use small alternating up-and-down kicks. Keep your legs higher or bend your knees if your lower back begins to lift.

Scissor Kicks

Move your legs across each other in a controlled pattern while maintaining your pelvis and torso position.

Reverse Crunch With Leg Raise

At the top of the leg raise, gently curl your pelvis and lift your hips a small distance. Lower your hips before lowering your legs. This is a separate, more advanced movement.

Hanging Leg Raise

Performing leg raises while hanging from a bar adds major grip and shoulder demands. It is much more advanced than the lying version and should be progressed separately.

Progress range, leg position or tempo before adding ankle weights. Extra resistance should not replace pelvic and lower-back control.

Common Lying Leg-Raise Mistakes

1. Lowering the Legs Too Far

The problem: You force your feet toward the floor while your lower back arches.

The fix: Stop your legs higher and use only the range you can control.

2. Allowing the Lower Back to Lift

The problem: A larger space develops under your lower back during the lowering phase.

The fix: Brace gently, bend your knees or shorten the range.

3. Moving Too Quickly

The problem: Your legs swing upward and drop toward the floor.

The fix: Slow both directions and pause briefly before changing direction.

4. Using Momentum

The problem: You throw your legs upward or bounce them from the bottom.

The fix: Begin every repetition from a stable position and lift smoothly.

5. Forcing the Knees Straight

The problem: You lock the knees aggressively and create excess tension.

The fix: Keep the knees soft. A slight bend is acceptable.

6. Lifting the Head and Shoulders

The problem: Your neck strains as your head leaves the floor.

The fix: Relax your head and keep your neck supported. Do not pull on your head with your hands.

7. Holding Your Breath

The problem: Breathing stops during the difficult part of the movement.

The fix: Use a steady exhale during the lift or controlled lowering phase.

8. Continuing After Form Breaks

The problem: You keep going while your back arches and your legs drop.

The fix: End the set or switch immediately to bent knees or a smaller range.

9. Adding Ankle Weights Too Soon

The problem: Extra load is added before the bodyweight version is controlled.

The fix: Improve your range, tempo and repetition quality before considering resistance.

How Many Lying Leg Raises Should You Do?

The best number depends on your ability to keep your pelvis and lower back controlled.

• Beginners: 2 sets of 5 to 8 bent-knee repetitions
• General fitness: 2 to 3 sets of 8 to 12 repetitions
• Timed circuit: 15 to 30 seconds of controlled movement
• BoardGains: Complete the number shown on the board

Stop when your lower back begins to lift, your breathing stops or your legs can no longer move smoothly. Good repetitions matter more than reaching a high number.

How to Teach Lying Leg Raises in a Group

Leg-raise range will vary across a class, so teach control instead of giving everyone the same bottom target.

1. Give every participant enough room to lie down without contacting another person.
2. Use mats when the floor is hard or uncomfortable.
3. Demonstrate the bent-knee version first.
4. Show how to brace without holding the breath.
5. Explain that the legs stop when the back begins to lose control.
6. Demonstrate the straight-leg option for participants who are ready.
7. Confirm that one controlled lift and lower equals one rep.
8. Allow participants to make the range smaller as they fatigue.

Lying Leg Raises in BoardGains

Lying leg raises are one of the 20 bodyweight exercises included in the BoardGains Pro game. They add a floor-based hip-flexion and core-control challenge to the mix of cardio, lower-body and upper-body movements.

When a player lands on the exercise, one controlled lift and lower counts as one repetition. Players can keep their legs straight, bend their knees or use a smaller range based on their ability.

Teaching the modification before gameplay helps everyone stay active. Players can switch to bent knees during the set without waiting for the coach or leaving the game.

Lying Leg-Raise FAQs

Are lying leg raises an ab exercise?

Your abdominal muscles help stabilize your pelvis and torso, but your hip flexors create much of the leg movement. It is best described as a hip-flexion exercise with a strong core-control demand.

Do lying leg raises work the lower abs?

The exercise challenges the rectus abdominis, but there is no separate lower-ab muscle to isolate. You may feel more tension toward the lower part of the abdominal area during the movement.

Should my legs touch the floor?

No. Lower only as far as you can without losing control of your pelvis and lower back. A higher bottom position is still a complete repetition.

Should my lower back stay on the floor?

Keep your pelvis and lower back supported. Stop lowering when your back begins to lift or arch more. Do not forcefully flatten your back if that position is uncomfortable.

Can I bend my knees?

Yes. Bending your knees shortens the lever and is a useful modification. It does not make the exercise pointless.

How do you count lying leg raises?

Raising both legs and lowering them through your controlled range equals one repetition.

Why do I feel lying leg raises in my hip flexors?

Your hip flexors are supposed to work because they lift the thighs. Bend your knees, shorten the range or end the set if the front of your hips becomes uncomfortable.

Why does my lower back hurt?

Your range may be too large, your legs may be too straight or your torso may no longer be controlled. Stop the exercise rather than pushing through pain. Try bent knees or a shorter range, and seek professional guidance if pain continues.

Can lying leg raises reduce belly fat?

No exercise can remove fat from one body area. Leg raises train muscles involved in hip flexion and trunk control, while body-composition changes depend on many factors.

Are leg raises better than crunches?

They are different exercises. Leg raises involve hip flexion and resisting unwanted pelvic movement. Crunches involve bending the trunk. The better choice depends on the person and the training goal.

Can I perform lying leg raises every day?

Daily practice is not required. Program them according to your total training load and allow recovery after challenging sets.

Are lying leg raises appropriate during pregnancy?

Exercise needs can change during pregnancy. Anyone who is pregnant should follow guidance from their healthcare professional, especially for exercises performed flat on the back.

Final Form Checklist

• Head, neck and shoulders relaxed
• Arms beside the body for support
• Core gently braced
• Knees straight or softly bent
• Legs raised and lowered without swinging
• Bottom position chosen by back and pelvic control
• Smaller range used when needed
• One complete lift and lower counted as one rep

The hardest version is not always the best version. Bend your knees and reduce the range until you can keep your torso controlled throughout every repetition. Lift with control, and lower until your back says stop.

Sources and Further Reading

• Mayo Clinic: Abdominal Ball Raise and Core Control
• National Academy of Sports Medicine: Dead Bug and Anti-Extension Core Control
• Mayo Clinic: Supine Active Straight Leg Raise and Lumbopelvic Stability