Leg Raises: How to Do Them Without Hurting Your Back
How to do lying leg raises correctly for lower abs: pelvic tilt, range of motion, common mistakes, bent-knee and advanced variations, and back-safety tips.
By Ayoub Farid · · 3 min read
Leg raises are a staple lower ab exercise, but many people feel them more in their lower back and hip flexors than their abs. The fix is all in the setup and range.
How to do a lying leg raise
- Lie on your back, legs straight, hands under your hips or by your sides.
- Press your lower back gently into the floor (a slight posterior pelvic tilt).
- Raise your legs until they're vertical.
- Slowly lower them, taking 2–3 seconds, only as far as your back stays down.
- Raise again. Breathe out as you lift.
For the lower abs to work, the pelvis must stay controlled. If your back peels off the floor, you've gone too low.
Common mistakes
| Mistake | Fix |
|---|---|
| Lower back arching | Shorten the range, bend knees |
| Swinging | Slow 3-second lowering |
| Neck straining | Rest your head down |
| Dropping legs to the floor | Stop a few centimeters above |
Variations
- Bent-knee leg raise: easiest
- Single-leg raise: one leg at a time
- Straight-leg raise: standard
- Leg raise with hip lift: at the top, lift hips slightly off the floor (a reverse crunch finish)
- Hanging leg raise: guide
- Bench leg raise: lying on a bench for more range
Sets and reps
Two to three sets of 8–15 reps. AbBlitz's lower ab library includes lying, bench, incline and hanging variations.
Leg raises and hip flexors
Your hip flexors lift your legs; your abs keep your pelvis from tipping. That's why leg raises work your abs isometrically, and why the reverse crunch (which actually curls the pelvis) is a great partner exercise. More in the lower ab workout.
Muscles worked
During a lying leg raise the hip flexors (iliopsoas, rectus femoris) lift the legs. The rectus abdominis, especially its lower portion, and the transverse abdominis work hard to stop your pelvis from tipping forward and your back from arching. So the abs are mostly working to hold position, which is why controlling the lowering phase matters so much.
A 4-week leg raise progression
| Week | Variation | Sets × reps |
|---|---|---|
| 1 | Bent-knee leg raise | 3 × 10 |
| 2 | Single straight-leg raise | 3 × 8 per side |
| 3 | Straight-leg raise, partial range | 3 × 10 |
| 4 | Straight-leg raise with hip lift at top | 3 × 8 |
Troubleshooting
- Feel it only in your hips? Add a small hip lift at the top (like a reverse crunch) and press your back down harder
- Feel it in your lower back? Stop higher, bend your knees, put hands under your hips
- Legs shaking? That's fatigue; finish the set with bent knees
Leg raise vs hanging leg raise
The lying version is easier to control and fine for most home routines. The hanging version adds range and grip demands, and is a big step up. Build to 3 × 15 controlled lying leg raises before trying hanging leg raises.
Frequently asked questions
Are leg raises bad for your back?
Not if your lower back stays down. If it arches, reduce the range or bend your knees.
Do leg raises burn lower belly fat?
No exercise burns fat in one spot. See the spot reduction myth.
How many leg raises should I do?
Two or three sets of 8–15 controlled reps.
Should I put my hands under my butt?
It can help keep the pelvis tilted. Move them to your sides as you get stronger.