Core · Bodyweight
Straight Leg Sit-up
How to do the straight leg sit-up, the muscles it works, and the mistakes to avoid. Pulled straight from the Kovo app's exercise library.
- Equipment
- Bodyweight
- Difficulty
- Intermediate
- Logged as
- Reps
- Movement
- Flexion
- Mechanic
- Isolation
How to do it
Lie flat on your back with your legs straight and together on the floor. Keep your legs down and sit all the way up by curling your torso toward your thighs, reaching for your toes, then lower back down with control.
- 1Your abs working hard to lift your torso without bent knees to help
- 2A smooth curl through the spine, one vertebra at a time
- 3Control on the way down rather than dropping flat
Common mistakes
- Yanking your head or neck to throw yourself up
- Letting your heels lift off the floor for leverage
- Bouncing off the floor at the bottom to start the next rep
Muscles worked
The straight 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
Kovo programs the straight 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.