Butterfly Crunches
Butterfly crunches put your legs in the soles-together diamond position and crunch from there — taking the hip flexors mostly out of the movement and leaving the abs to do the lifting alone. It is a smart pick for people who feel ordinary crunches in their hips or thighs instead of their midsection. 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 (3 s up, 3 s down) | 60–90 s |
| Muscle | 3 × 9–12 | 60 s |
| Endurance | 2–3 × 18–27 | 45 s |
Rep ranges per Helms 2014 · Schoenfeld 2016.
Level — Beginner
Beginner-friendly — and often the version that finally teaches people what abs working feels like.
Proper form — 5 cues
- Lie back, press your soles together, and let the knees fall open wide.
- Rest your fingertips behind your ears with elbows wide.
- Curl the ribs toward the pelvis, lifting the shoulder blades off the floor.
- Pause at the top and squeeze for one full second.
- Lower slowly until the shoulder blades — not the head — touch down.
Breathing: Exhale fully as you curl up, inhale on the slow lower.
The 3 mistakes Maddy corrects most
Common questions
Why do the legs go in the butterfly position for crunches?
With the soles together and knees dropped wide, the hip flexors are placed in a position where they cannot pull effectively — so they stop helping. Whatever curls your torso up has to be abdominal muscle. If ordinary crunches always end up burning your hips or thighs, this leg position usually solves it in one session.
How high should I crunch up?
Only until the shoulder blades clear the floor — roughly 30 degrees of trunk curl. Higher than that recruits the hip flexors and adds nothing for the abs. The quality markers are a one-second squeeze at the top and a slow lowering, not altitude. Small and strict beats big and swingy every time.
Butterfly crunches vs regular crunches — which should I do?
If regular crunches give you clean ab work with no hip or neck complaints, either is fine. Choose the butterfly version when you want to isolate the abs harder, when your hip flexors dominate everything, or simply for variety across the week. Many programs use both — same movement skill, different leg position.
Related exercises
Easier: Crunches · Harder: Butterfly Crunches (Advanced)
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