Hip flexors dominate — spine barely flexes
The sit-up becomes a pure hip flexor exercise with no true abdominal loading.
Overactive muscles
Hip flexorsRectus femoris
Corrective work
Foam RollHip flexors↗StretchHalf-kneeling hip flexor stretch↗Core · Core
Sit-Up (Standard)
Coaching cues
- Lie on your back; knees bent at 90°; feet flat; arms crossed
- Sit all the way up until the trunk is vertical
- Lower under control — 3-second eccentric
- Full range distinguishes the sit-up from a crunch
Common faults 2
Feet come off the floor at the top
The eccentric overloads the hip flexors without the feet being anchored.
Overactive muscles
Hip flexorsErector spinae
Corrective work
Foam RollHip flexors↗StretchHalf-kneeling hip flexor stretch↗