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Flexion Leg Sit Up (Straight Arm)
A sit-up performed with legs flexed and arms held straight overhead-forward, lengthening the lever to make the trunk flexion harder without external load.
AbsBodyweightTrunk flexion
GoLightWeight mediaflexion-leg-sit-up-straight-arm
Demonstration coming soon
Primary
Rectus abdominis
Secondary
Hip flexorsObliquesSerratus anterior
Equipment
Bodyweight
Pattern
Trunk flexion
Setup
- 01Lie on your back on a mat with knees bent and feet flat on the floor.
- 02Extend both arms straight overhead so they are in line with the torso.
- 03Press the lower back gently toward the floor and set the ribs down.
- 04Keep the feet unanchored or lightly anchored, whichever lets the abs lead.
Execution
- 01Exhale and sweep the straight arms forward as the trunk curls off the floor.
- 02Roll up one segment at a time until the torso is upright over the hips.
- 03Keep the arms straight and reaching toward or past the knees at the top.
- 04Lower back down under control, letting the spine uncurl vertebra by vertebra.
Checkpoints
- -Arms stay straight for the entire rep, not bending to cheat momentum.
- -The trunk curls segmentally rather than hinging as one stiff plank.
- -Feet stay quiet; the heels do not slam down to counterbalance.
- -The lowering phase takes at least as long as the way up.
Common mistakes
- -Throwing the arms to generate momentum instead of curling with the abs.
- -Yanking the neck forward at the sticking point.
- -Letting the lower back arch off the floor at the start position.
- -Dropping back to the floor instead of controlling the eccentric.
Programming notes
- -Use 2 to 4 sets of 8 to 15 controlled reps as a main trunk flexion exercise.
- -If full reps are too hard, shorten the arm lever by crossing arms on the chest, then progress back.
- -Slow 3 second eccentrics add difficulty without adding load.
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