Alternating Leg Raise
The alternating leg raise is a lying leg raise in which both legs come up with the knees bent and go back down with the knees straight. It works the hip flexors and abs, making the way down harder than the way up, and it is the step between knee raises and the full straight-leg raise.
Also called: Alternating Leg Raises, Bent-to-Straight Leg Raise · Equipment: bodyweight · Pattern: isolation
Step by step
- Lie flat on your back with your arms by your sides and your legs together.
- Bend both knees to about 45° and lift your heels just off the floor.
- Raise your legs together until your knees are over your hips, keeping the knee bend.
- At the top, straighten both legs and push them up, curling your hips slightly off the floor.
- Pause for a second, feeling your hips and abs working.
- Bring your straight legs back down slowly, keeping the small of your back on the floor, until your heels are about an inch above it.
- Pause for a second, bend your knees again and start the next rep with your heels still off the floor.
- Bend going up, straight coming down
- Both legs move together
- Back flat on the floor
- Heels hover above the floor
- Slow on the way down
In VALDA, these cues are one tap away on the exercise while you train.
What it trains
| Muscle | Role | Evidence |
|---|---|---|
| Hip flexors: iliopsoas | Prime mover | B |
| Hip flexors: rectus femoris | Prime mover | B |
| Rectus abdominis: lower | Secondary | C |
| Obliques (internal/external) | Stabiliser | C |
Evidence grades: A = strong research base · B = good · C = limited · D = coaching consensus.
What goes wrong, and the fix
Resting the heels on the floor
Fix: Pause with your heels about an inch above the floor instead.
Straightening too early
Fix: Keep the knees bent until they are over your hips.
Arching the back off the floor
Fix: Keep the small of your back on the floor as the legs come down.
Dropping the legs
Fix: Take two to three seconds to bring your straight legs down.
Swinging into the top
Fix: Raise your legs under control and pause for a second at the top.
What the research says
General fitnessEndurance
- Muscles worked — EMG research finds leg raises are led by the hip flexors, with less abdominal activity than the sit-up; hip-flexor activity is high only when the hip itself flexes.
- Slow way down — A meta-analysis found eccentric-weighted training at higher intensities built more strength and muscle than concentric training, which is the idea behind the straight-leg descent.
- Endurance — Reviews of loading find lighter loads with higher reps favour local muscular endurance, which bodyweight leg raises mainly train. There is no direct research on this variation.
- Standards — Hybrid Calisthenics uses 2 sets of as many good reps as possible with 2–3 minutes' rest, from 2 sets of 10 up to 2 sets of 25 before the full leg raise.
Log the alternating leg raise in VALDA, with these cues one tap away while you train and your history for it in one place.
General information about exercise technique, not medical advice. If you have an injury or a health condition, your healthcare provider is the right person to ask.