Seated Knee-to-chest Crunch v Hold
The seated knee-to-chest crunch V hold is an isometric chair-based core exercise that holds the knees toward the chest from a seated position. The sustained contraction intensifies the demand on the abs and hip flexors compared to the standard knee-to-chest crunch variation.
How to do it
- Sit on the edge of a chair and grip the sides of the seat for support.
- Lean back slightly and lift both feet off the floor, drawing your knees toward your chest.
- Hold the knees-to-chest position for the desired duration.
- Keep your core fully contracted and your lower back from rounding excessively.
- Lower your feet and return to the starting position before repeating.
Form cues
- Sit tall on the edge of the chair and grip the sides firmly.
- Lean back slightly while keeping your chest open.
- Draw your knees toward your chest using your abs.
- Hold the position steadily without holding your breath.
Breathing: Inhale deeply to prepare, then exhale steadily as you lean back and hold your knees up, breathing smoothly throughout the hold.
Common mistakes
- Rounding the lower back excessively, which places unnecessary pressure on your spine.
- Using momentum to swing your knees up instead of engaging your abs.
- Holding your breath during the hold, which raises blood pressure and tires you out faster.
Muscles worked
Primary: abs. Secondary: hip flexors, lower back.
Suggested sets & reps
Get fitter
3 sets × 20-30 seconds hold, rest 60 seconds
Lose weight
3 sets × 20-30 seconds hold, rest 45 seconds
Build muscle
3-4 sets × 30-45 seconds hold, rest 60 seconds
Easier, harder & alternatives
Make it easier
Make it harder
Take care if…
- If you feel sharp lower back pain, ease off and choose a gentler option.
General educational guidance, not medical advice. Stop on sharp pain and check with a qualified professional if unsure.
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Start free →Frequently asked questions
Where should I feel this exercise?
You should feel your abdominal muscles working to keep your legs elevated, and potentially some mild tension in your hip flexors.
What if I feel it in my lower back?
This usually happens if your lower back rounds too much. Sit up a bit taller, lean back less, and brace your core.
Can I do this exercise every day?
It is generally fine to do a few times a week, but your core needs recovery time just like any other muscle group.