Flexion Leg Sit Up (straight Arm)
Use pure bodyweight leverage to build bracing strength that carries over: Flexion Leg Sit Up (straight Arm) closes out a session in minutes.
How to do Flexion Leg Sit Up (straight Arm)
- Lie flat on your back with your legs extended and arms straight above your head.
- Engaging your abs, lift your upper body off the ground while simultaneously lifting your legs towards your chest.
- Reach your hands towards your toes as you lift your upper body and legs.
- Pause for a moment at the top, then slowly lower your upper body and legs back down to the starting position.
- Repeat for the desired number of repetitions.
Flexion Leg Sit Up (straight Arm) Sets and Reps by Goal
Strength
3 sets of 6-8 hard reps with 2 minutes of rest. Change leverage or elevation before you add load.
Hypertrophy
3 sets of 10-15 reps with 60-90 seconds of rest. Hold the end position for a beat once reps come easily.
Endurance
2-3 sets of 20-25 reps with 45 seconds of rest. Add reps first, then slow the lowering phase.
Common Flexion Leg Sit Up (straight Arm) Mistakes
Shortening the range as soon as the set gets hard
End the set on the last full-range rep instead of grinding out halves.
Pulling with the hip flexors while the abs stay slack
Start every rep by flattening the lower back down, then move.
Easier and Harder Than Flexion Leg Sit Up (straight Arm)
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Flexion Leg Sit Up (straight Arm) — Frequently Asked Questions
How do you do the Flexion Leg Sit Up (straight Arm)?
Lie flat on your back with your legs extended and arms straight above your head. Engaging your abs, lift your upper body off the ground while simultaneously lifting your legs towards your chest. Reach your hands towards your toes as you lift your upper body and legs. Use your bodyweight only and keep the movement controlled through the full range. The animated GIF above shows the complete rep at normal speed.
What muscles does the Flexion Leg Sit Up (straight Arm) work?
The Flexion Leg Sit Up (straight Arm) primarily targets the abs. It is classified as a core exercise and is performed with your bodyweight only.
How many sets and reps of the Flexion Leg Sit Up (straight Arm) should I do?
For muscle growth: 3 sets of 10-15 reps with 60-90 seconds of rest. Hold the end position for a beat once reps come easily. Adjust the load rather than the rep target if form breaks down before the final rep.
Is the Flexion Leg Sit Up (straight Arm) good for beginners?
Yes. The Flexion Leg Sit Up (straight Arm) is a beginner-level movement, so it is a reasonable place to start. Keep the load light enough that you can control every rep and stop 2-3 reps short of failure while you learn the pattern.
What can I do instead of the Flexion Leg Sit Up (straight Arm)?
Try the Band Standing Crunch, Cable Seated Crunch or the Lever Seated Leg Raise Crunch. Each trains the abs with a similar movement pattern, so you can swap based on the equipment you have available.
