Bent Knee v Sit Up
The bent knee V sit-up is a bodyweight abdominal exercise that targets the abs by simultaneously raising the torso and bent knees to a balanced V shape. It develops core strength and hip flexor coordination.
How to do it
- Lie flat on your back with arms extended overhead and knees bent.
- In one motion, lift your torso and bring your knees toward your chest while reaching your hands forward.
- Balance on your tailbone in the V position, keeping your core tight.
- Hold briefly, then slowly lower both your torso and feet back to the starting position.
- Repeat for the desired number of repetitions.
Form cues
- Keep your core tight as you lift your torso and knees together.
- Balance smoothly on your tailbone at the top of the movement.
- Reach your hands forward toward your knees for stability.
- Lower your upper and lower body back down with control.
Breathing: Exhale as you lift your torso and knees into the V position, and inhale as you lower back down with control.
Common mistakes
- Using momentum to swing up, which reduces muscle engagement in the abs.
- Rounding the lower back excessively, which places unnecessary strain on the spine.
- Dropping the legs quickly instead of lowering them slowly, which shortens the time under tension.
Muscles worked
Primary: abs. Secondary: hip flexors, obliques.
Suggested sets & reps
Get fitter
3 sets x 10-12 reps, rest 60 s
Lose weight
3 sets x 12-15 reps, rest 45-60 s
Build muscle
3-4 sets x 8-12 reps, rest 60-90 s
Easier, harder & alternatives
Take care if…
- If you feel sharp lower back or hip pain, ease off and choose a gentler core movement.
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
What should I do if I feel this in my lower back?
If you feel discomfort in your lower back, your core may be fatiguing or your back is rounding. Try a regression like a half v-sit or focus on keeping a smaller range of motion.
How often can I do bent knee v sit-ups?
2 to 3 times per week is plenty for most beginners to allow for proper recovery of the abdominal muscles.
Can I do these on a hard floor?
It is best to perform this exercise on a yoga mat or a carpeted surface to protect your tailbone from discomfort against hard flooring.