Lying Leg Raise: Form Guide for Lower Abs
The lying leg raise is one of the best floor exercises for your lower abs, as long as you keep your back from arching. Here's exactly how to do it right.
The lying leg raise is a floor exercise where you lie on your back and lift your legs from the floor to vertical, then lower them under control. Done well, it works your whole rectus abdominis with extra emphasis on the lower portion, plus your hip flexors. The single most important form point is keeping your lower back pressed toward the floor as your legs lower. If your back arches, the exercise shifts away from your abs and toward your hip flexors and spine.
Here's how to do it, the mistakes to avoid, and how to make it easier or harder.
What muscles the lying leg raise works
- Rectus abdominis. Your "six-pack" muscle works to stop your pelvis tipping forward as your legs lower, and to curl your pelvis up at the top.
- Hip flexors (iliopsoas, rectus femoris). These lift your legs. They do a lot of the work, which is fine, as long as your abs are controlling your pelvis.
- Deep core (transverse abdominis). Helps keep your trunk braced and stable.
- Obliques. Assist with stabilization.
You can't isolate the "lower abs" as a separate muscle, since the rectus abdominis is one long muscle. But exercises that move your pelvis toward your ribs, like leg raises and reverse crunches, tend to emphasize the lower region more than crunches do. For more on this, see our lower ab workout.
How to do a lying leg raise
- Lie on your back on a mat with your legs straight and arms by your sides, palms down. Some people prefer hands slightly under their hips or gripping something behind their head for stability.
- Exhale and gently press your lower back toward the floor. Your ribs should feel "down," not flared up.
- Keeping your legs straight (or slightly bent), lift them until they point roughly at the ceiling.
- At the top, optionally curl your hips an inch off the floor by tilting your pelvis back. This extra bit is where your abs work hardest.
- Lower your legs slowly, taking 2-3 seconds, only as far as you can while keeping your lower back in contact with the floor.
- Stop just before your heels touch, then repeat.
Breathing: exhale as you lift, inhale as you lower, or keep a steady brace and breathe at the top. Don't hold your breath for the whole set.
The most common mistakes
Letting your lower back arch
This is the big one. As your legs get close to the floor, they act like a long lever pulling your pelvis forward. If your abs can't resist, your lower back arches off the mat. Fix it by stopping higher, bending your knees, or going back to an easier variation.
Dropping the legs too fast
The lowering phase is the hard part and the most useful part. If you let gravity take your legs down, you skip most of the benefit.
Swinging up with momentum
Bouncing off the floor to get your legs up turns the set into a hip flexor exercise. Start each rep from a controlled position just above the floor.
Craning your neck
Keep your head resting on the floor and your chin slightly tucked. Lifting your head doesn't add ab work; it just strains your neck.
Going straight to straight legs
Straight legs make the lever longer and much harder. Most people should start bent-knee and earn the straight-leg version.
Progressions from easiest to hardest
| Level | Variation | Target |
|---|---|---|
| 1 | Bent-knee leg raise (knees at 90 degrees, heels tap floor) | 3 x 12-15 |
| 2 | Single-leg lowers (one leg stays up) | 3 x 8-10 per side |
| 3 | Straight-leg raise, partial range | 3 x 10-12 |
| 4 | Straight-leg raise, full range, 3-second lower | 3 x 10-12 |
| 5 | Leg raise with hip lift at the top | 3 x 8-12 |
| 6 | Leg raise with light ankle weights or a held dumbbell between feet | 3 x 8-10 |
| 7 | Hanging leg raise | See our hanging leg raise guide |
Move to the next level once you can complete all sets at the top of the rep range while keeping your lower back down on every rep. The progressive overload for abs guide explains why tempo and range changes work so well for bodyweight core exercises.
Sample lower-ab session using leg raises
Rest 45-60 seconds between sets.
- Lying leg raise (your level): 3 sets x 10-12 reps
- Reverse crunch: 3 sets x 12-15 reps
- Dead bug: 3 sets x 8 reps per side
- Hollow body hold: 2 sets x 20-30 seconds
This covers lower-ab emphasis, anti-extension control and deep core work in about 12-15 minutes. Pair it with an upper-ab or oblique exercise on another day for a balanced week. If you want to swap in alternatives, the ab exercise finder lets you search by target and equipment.
Lying leg raise vs similar exercises
- Reverse crunch: shorter lever, more focus on curling the pelvis up. Easier on the lower back and often better for beginners.
- Flutter kicks: small alternating movements held near the floor. More of an endurance and anti-extension drill. See our guide to flutter kicks.
- Hanging leg raise: much harder, adds grip and a full-body hang, and lets your pelvis curl through a bigger range.
- V-ups: combine a leg raise with a crunch for a full-range, more explosive movement.
A good program often includes the lying leg raise as a stepping stone to hanging variations.
Is the lying leg raise bad for your back?
It doesn't have to be. Problems usually come from letting the back arch under a long lever, especially with fast reps. Keep the range within what you can control, start bent-knee, and focus on slow lowering. If you have existing lower back pain or a back condition, talk to a doctor or physical therapist before adding leg raises, and stop if an exercise causes pain rather than muscular effort.
Will leg raises give you visible lower abs?
They'll make the muscle stronger and better developed. Whether you can see it depends on your body fat, and the lower belly is often the last area to lean out for many people. That's normal and not a training failure. Our article on stubborn lower belly fat covers what actually helps, and the body fat calculator can give you a rough starting estimate.
Where AbShred fits
AbShred is an iPhone app (currently on a waitlist) that scores your Lower Abs, along with five other zones, from a single photo, then builds a weekly plan starting with your weakest zone, with exercise demos. It's an AI estimate for motivation, not a medical measurement. Join the waitlist at abshred.com.
FAQ
How many lying leg raises should I do?
Start with 3 sets of 10-15 reps of whichever variation you can do with your lower back staying down. When that's easy, make the variation harder rather than doing 30 or 40 reps.
Why do I feel leg raises in my hip flexors?
Your hip flexors do lift your legs, so some sensation there is normal. If it's mostly hip flexors and little ab work, you're probably letting your back arch or swinging. Shorten the range, bend your knees, and add a small pelvic curl at the top.
Should my feet touch the floor between reps?
Usually no. Stopping just above the floor keeps tension on your abs. Beginners doing bent-knee versions can tap their heels lightly.
Are lying leg raises better than crunches?
Neither is better; they emphasize different areas. Crunches favor the upper abs, while leg raises and reverse crunches favor the lower region. Using both gives a more complete result.
Can I do lying leg raises every day?
You can do a few easy sets often, but hard sets are better spread over two to four sessions a week so you can recover and keep form sharp.