Primary Muscles
Rectus abdominis (lower fibres), iliopsoas, rectus femoris
Core
Leg Raise
The most direct way to load the lower abs — works hip flexors and the lower fibres of the rectus abdominis.
3D animation — watch the full movement
Secondary Muscles
Transversus abdominis, internal/external obliques
Equipment
None (mat optional) / Pull-up bar (for hanging variation)
Location
Home / Gym
Difficulty
Beginner → Intermediate
How to Do It
- Lie on your back. Hands at your sides or under your lower back for lumbar support. Legs straight.
- Engage your core. Raise both legs together, straight, to 90° (2 s up).
- Pause briefly at the top — a small hip tilt off the floor is normal.
- Lower legs back down with control (3 s). Stop just before they touch the floor, then repeat.
- Lower back must stay neutral. If it lifts, soften the knee bend to reduce the lever.
Common Mistakes
- Letting legs drop to the floor — muscles rest and momentum is lost. Keep them suspended.
- Arching the lower back (hyperlordosis) — disc pressure. Tuck hands under hips, push back down.
- Lowering too fast — the eccentric is the most valuable phase. Take 3 s on the way down.
- Holding your breath — inhale on the way down, exhale on the way up.
- Bending the knees — reduces the load; fine for beginners but lower abs work less.
Beginner Tips
- Start with knee raises (both knees bent), then gradually straighten the legs over weeks.
- Back issues? Place hands under your lower back to press the lumbar spine toward the floor.
- 3×10 reps is a solid start. Ready for more? Add ankle weights or progress to hanging leg raises.
- Leg raises heavily recruit hip flexors — especially valuable for desk-bound individuals.
Frequently Asked Questions
Do leg raises really work the lower abs?
Yes. The lower fibres of the rectus abdominis and the iliopsoas are loaded. Strictly speaking, 'upper vs lower abs' is relative — rectus abdominis is one muscle, but different fibres are preferentially activated. Crunches emphasise upper, leg raises emphasise lower.
Leg raises hurt my lower back — should I keep going?
No. Pain signals a form error. Place hands under your hips and try bent-knee raises. If pain persists, seek physiotherapy assessment.
How many reps should I do?
3×10-15 is solid. Too easy? The hanging leg raise (from a pull-up bar) is the most challenging variation. Ankle weights, a ball squeezed between feet, or incline bench variations are also good progressions.
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