Laying Leg in and Out
Lying leg in-and-outs tuck both knees to the chest and shoot them back out while the shoulders stay grounded, hammering the lower abdominal region through repeated compression and extension. They suit floor-core circuits where the seated version bothers the tailbone or balance. 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 | 4 × 5–6 (legs extending low and slow) | 90 s |
| Muscle | 3–4 × 9–12 | 60–90 s |
| Endurance | 3 × 18–27 | 45–60 s |
Rep ranges per Helms 2014 · Schoenfeld 2016.
Level — Beginner
Beginner — extension height is the difficulty dial; lower legs mean a harder set.
Proper form — 5 cues
- Lie back with shoulders relaxed on the mat and hands anchored beside the hips.
- Tuck both knees in toward the chest until the lower back gently rounds.
- Extend the legs out long and low — the lower, the harder — without the back arching.
- Keep the heels off the floor for the entire set; hovering is the contract.
- Move with rhythm but never bounce — each tuck and each extension is deliberate.
Breathing: Exhale as the legs shoot out — the moment of truth for the brace — inhale on the tuck.
The 3 mistakes Maddy corrects most
Common questions
Lying vs seated in-and-outs — which is better?
The lying version anchors the shoulders and spine, which makes back position easier to monitor and removes the balance demand, so it is usually the better teaching version. The seated version adds a hip-hinge balance element and hits the hip flexors harder. Both are legitimate; sequence lying first.
How low should my legs extend?
Exactly as low as your lower back can stay quietly pressed toward the mat — that height is different for everyone and it improves with training. Forty-five degrees is a common starting angle. Chasing a lower extension while the back arches is trading progress for strain.
Can I do these every day?
The abs recover like any muscle: they adapt between sessions, not during them. Two to four focused core sessions per week with progression beats daily repetition of the same sets. If you love daily floor work, rotate this with planks and anti-rotation drills instead of repeating it.
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