Core · Bodyweight
Straight Arm Flexion Leg Sit-up
How to do the straight arm flexion leg sit-up, the muscles it works, and the mistakes to avoid. Pulled straight from the Kovo app's exercise library.
- Equipment
- Bodyweight
- Difficulty
- Beginner
- Logged as
- Reps
- Movement
- Flexion
- Mechanic
- Isolation
How to do it
Lie on your back with your knees bent and feet flat, arms extended straight overhead on the floor. Keeping your arms straight, swing them forward as you curl your torso up into a full sit-up, reaching toward your knees or feet. Lower back down under control to the start.
- 1Feel your abs pull your torso up as your arms swing forward
- 2Curl your spine up one segment at a time rather than yanking
- 3Keep your feet planted and core braced through the full rep
Common mistakes
- Don't throw your arms to fling yourself up with momentum
- Avoid pulling from your hip flexors and arching your back
- Don't drop back down flat; lower with control
Muscles worked
The straight arm flexion leg sit-up mainly works the upper abs, with the lower abs, hip flexors, and obliques assisting.
- Upper AbsPrimary
- Lower AbsSupport
- Hip FlexorsSupport
- ObliquesSupport
- QuadsMinor
- Front DeltsMinor
Kovo programs the straight arm flexion leg sit-up for you and tracks it every session.
We build your whole program, drop the right lifts into each workout, and adjust your weights as you get stronger. Free on iOS and Android.
More abs & core exercises
- How to do the ab wheel rollout
- How to do the ankle tap plank
- How to do the ankle taps
- How to do the resistance band dead bugs
- How to do the resistance band pallof press
- How to do the rollout
Last reviewed June 2026.