Alternate Leg Raises (Modified)
The modified alternate leg raise keeps one foot planted with the knee bent while the other leg raises and lowers straight — halving the load on your abs while you learn the pattern. It is the right entry point for beginners and anyone whose lower back arches during full leg raises. Coached by Maddy (NASM-CPT) — these are the exact form cues he gives on every client's first week.
Muscles worked
Sets & reps by goal
| Goal | Sets × Reps | Rest |
|---|---|---|
| Strength | 3 × 3–6 per leg (slow 4 s lowering) | 60–90 s |
| Muscle | 3 × 9–12 per leg | 60 s |
| Endurance | 2–3 × 18–27 per leg | 45 s |
Rep ranges per Helms 2014 · Schoenfeld 2016.
Level — Beginner
The gentlest version of the leg-raise family — master it here before straightening both legs.
Proper form — 5 cues
- Bend the resting knee and plant that foot flat — it stays down for the whole side.
- Flatten your lower back against the floor before the working leg moves.
- Raise the straight leg to vertical, or as high as the knee stays locked.
- Lower it over 2–3 seconds until the heel hovers just above the floor.
- Finish the planned reps on one leg before switching, or alternate slowly and deliberately.
Breathing: Exhale as the leg lowers, inhale as it lifts — reverse of what most people guess.
The 3 mistakes Maddy corrects most
How to program alternate leg raises (modified)
| Goal | Phase | Sets | Reps | Tempo | Rest | RPE |
|---|---|---|---|---|---|---|
| strength | weeks 1–4 · build | 3 | 6 per leg | 4-0-2-0 | 60–90 s | 7 |
| strength | weeks 5–8 · intensify | 3 | 4 per leg | 4-0-2-0 | 60–90 s | 8 |
| strength | weeks 9–12 · peak | 3 | 3 per leg | 4-0-2-0 | 60–90 s | 9 |
| hypertrophy | weeks 1–4 · build | 3 | 12 per leg | 3-0-2-0 | 60 s | 7 |
| hypertrophy | weeks 5–8 · intensify | 3 | 10 per leg | 3-0-2-0 | 60 s | 8 |
| hypertrophy | weeks 9–12 · peak | 3 | 9 per leg | 3-0-2-0 | 60 s | 8–9 |
| endurance | weeks 1–4 · build | 2 | 18 per leg | 2-0-2-0 | 45 s | 6 |
| endurance | weeks 5–8 · intensify | 3 | 22 per leg | 2-0-2-0 | 45 s | 7 |
| endurance | weeks 9–12 · peak | 3 | 27 per leg | 2-0-2-0 | 45 s | 7–8 |
| beginner | weeks 1–4 · learn | 2 | 8 per leg | 3-0-2-0 | 60–90 s | 5 |
| beginner | weeks 5–8 · groove | 3 | 10 per leg | 3-0-2-0 | 60–90 s | 6 |
| beginner | weeks 9–12 · load | 3 | 10 per leg | 3-0-2-0 | 60–90 s | 6–7 |
Tempo = eccentric-pause-concentric-pause, seconds (X = explosive intent).
Common questions
Can complete beginners do modified leg raises?
Yes — this is precisely the version built for you. The bent, planted leg stabilises your pelvis so the working side can move through a full range without your lower back arching. Start with 8 slow reps per leg; when 15 feel controlled, straighten the resting leg along the floor as your next step.
When should I move to the full version?
When three things are true: 15 clean reps per leg here, a lower back that never leaves the floor, and a lowering phase you can genuinely slow down on command. Rushing to the straight-leg scissors early usually just teaches an arch — a habit that takes longer to unlearn than the strength takes to build.
Are leg raises better than crunches?
They bias different regions. Crunches shorten the upper portion of the rectus abdominis by curling the ribs down; leg raises challenge the lower portion and hip flexors by controlling the pelvis against the weight of the legs. Neither replaces the other — a complete core plan includes both patterns.
Why does my back still arch in the modified version?
The bent, planted leg should be taking half the load — if your back arches anyway, the working leg's lever is still too long for your current strength. Bend the moving knee slightly, shorten the range so the leg lowers only about halfway, and press your lower back into the floor before every rep. Exhale as the leg lowers, which helps the abs keep the pelvis pinned. Regressing the range for two weeks usually fixes the arch.
How should I breathe during modified leg raises?
Set your brace first: exhale firmly, feel the ribs drop and the lower back settle into the floor, then take a small breath and hold that tension. From there, exhale slowly as the leg lowers — the hardest phase — and inhale as it returns. Never hold your breath through multiple reps or let the belly balloon on the inhale, since both release the pelvic control this exercise is teaching. Rhythm matters more than volume of air.
Related exercises
Harder: Alternate Leg Raise (Advanced)
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