Abs · Bodyweight
Straight Arm Crunch
The straight arm crunch is a core exercise that extends the body's lever arm to place targeted demand on the rectus abdominis. It suits practitioners of all fitness levels and works best toward the end of a session as an isolation movement.
- Muscles
- Abs
- Equipment
- Bodyweight
- Type
- Strength
- Animation
- Men and women
How to do it
- Lie on your back with your arms extended straight up toward the ceiling.
- Keep your knees bent and feet flat on the floor.
- Engage your core and keep your arms straight throughout.
- Crunch up by lifting your shoulders off the ground.
- Slowly return to the starting position while maintaining arm position.
Common mistakes
- Bending the elbows shortens the resistance lever and reduces tension on the abdominal wall.
- Swinging the arms forward uses momentum rather than core contraction to elevate the torso.
- Lifting the lower back off the floor shifts the workload onto the hip flexors and places unnecessary strain on the spine.
- Tucking the chin aggressively into the chest strains the neck instead of engaging the upper abs.
Tips
- Keep your eyes fixed on the ceiling to maintain a neutral cervical spine throughout the movement.
- Pause for a full second at the top of the crunch while exhaling completely to maximize peak contraction.
- Lower your shoulder blades back to the floor slowly to keep the core under continuous tension.
Sets and reps
Perform 3 to 4 sets of 12 to 20 controlled repetitions, resting 45 to 60 seconds between sets to build local muscular endurance and core stability.
Muscles worked
Your coach guides every set
Turn on the coach in Gloox: it asks how you feel, picks the weight from your history and cues technique and rest. Rate each set and the next one is tuned to you.
On a computer? Point your phone's camera here to get the app.
Questions
Is the straight arm crunch safe for the lower back?
Yes, provided the lower back stays pressed firmly against the floor while only the shoulder blades lift; if you experience sharp or lingering pain, stop and consult a qualified specialist.
How can you make this exercise harder without weights?
You can increase the difficulty by reaching your arms backward closer to your ears rather than straight up toward the ceiling, which further lengthens the lever arm.
