Twisting Crunch (Straight Arms)
- Target muscle
- Obliques, Rectus Abdominis
- Equipment
- Body weight
- Body part
- Waist
- Type
- Strength
The twisting crunch with straight arms is a bodyweight core exercise that targets the obliques and rectus abdominis simultaneously. By extending the arms overhead and rotating at the top of each crunch, you increase the load on the obliques while keeping the rectus abdominis under tension throughout the movement. It requires no equipment and is an effective choice for building rotational core strength.
How to do the Twisting Crunch (Straight Arms)
- 1Lie flat on your back on a mat with your legs bent, feet flat on the floor roughly hip-width apart.
- 2Extend both arms straight overhead, keeping them close to your ears and parallel to each other.
- 3Brace your core and press your lower back gently into the mat.
- 4Begin the crunch by curling your chin toward your chest and lifting your shoulder blades off the mat.
- 5As your torso rises, rotate through your waist so your arms and chest angle toward your right knee.
- 6Hold the twisted position for a brief pause, feeling the contraction in your obliques and rectus abdominis.
- 7Slowly lower your torso back to the mat under control, returning your arms to the overhead starting position.
- 8Repeat the movement, this time rotating toward your left knee.
- 9Continue alternating sides for the full set.
Form tips
- Drive the rotation from your waist, not your shoulders — keep your arms passive and let your core initiate the twist.
- Exhale fully as you crunch and rotate; inhale on the way back down to maintain intra-abdominal pressure.
- Keep your chin lifted slightly away from your chest throughout the rep to avoid straining your neck.
- Move slowly on the descent — resisting gravity on the way down increases time under tension for both the obliques and rectus abdominis.
- Anchor your feet under a stable object only if you cannot stop your legs from lifting; if your hip flexors are taking over, slow the tempo instead.
Common mistakes
- Pulling on the neck or swinging the arms to gain momentum, which takes load off the core and risks cervical strain.
- Rotating the hips instead of the waist, which turns the movement into a hip roll rather than an oblique contraction.
- Crunching only a few inches and not lifting the shoulder blades fully off the mat, which reduces the range of motion and the stimulus on the rectus abdominis.
- Holding the breath throughout the rep, which raises blood pressure unnecessarily — exhale on the way up.
- Rushing through reps to hit a number, which sacrifices the controlled descent and removes much of the oblique workload.
Frequently asked questions
What muscles does the twisting crunch with straight arms work?
It primarily works the obliques and rectus abdominis. The straight-arm reach extends the resistance arm of the crunch, and the rotation at the top specifically emphasizes the obliques on each side.
How is the twisting crunch different from a regular crunch?
A standard crunch flexes the spine forward to work the rectus abdominis. Adding a twist engages the obliques on top of that, making it a more complete abdominal exercise without needing any equipment.
Is the twisting crunch with straight arms suitable for beginners?
Yes, with care. Because the extended arms increase the difficulty compared to a standard crunch, beginners should focus on controlled movement and a full range of motion rather than high rep counts. Reduce rep speed if you feel your neck straining.
How many sets and reps should I do?
Two to four sets of 10–20 reps per side is a practical starting range. Prioritize quality of rotation and control over volume — once form breaks down, stop the set.
Where should I feel this exercise?
You should feel the contraction in the front of your abdomen (rectus abdominis) throughout the crunch and a distinct squeeze along the side of your torso (obliques) at the peak of each twist. If you feel it primarily in your neck or hip flexors, slow the tempo and focus on initiating the movement from your core.
