Jackknife Beginners
The jackknife beginners is a Pilates bodyweight exercise targeting the abdominal muscles and hip flexors. This entry-level variation focuses on controlled leg lifting and a gentle hip raise, building the core strength needed for the full jackknife movement.
How to do it
- Lie flat on your back with your arms by your sides and legs extended.
- Engage your core and slowly lift your legs to a 90-degree angle.
- Press your palms into the mat for support as you gently lift your hips off the mat.
- Slowly lower your hips and legs back to the starting position with control.
- Repeat for the desired number of repetitions.
Form cues
- Keep your lower back pressed into the mat
- Move slowly and with control
- Engage your core before lifting your legs
- Use your hands for gentle support
- Focus on the lift coming from your abs
Breathing: Exhale deeply as you lift your legs and hips; inhale slowly as you return to the starting position.
Common mistakes
- Using momentum to swing legs, which reduces core activation
- Arching the lower back, which can cause discomfort
- Lifting the head and neck, which adds unnecessary strain
Muscles worked
Primary: abs. Secondary: hip flexors, lower back.
Suggested sets & reps
Get fitter
3 sets x 10-12 reps, rest 60s
Lose weight
3 sets x 12-15 reps, rest 45s
Build muscle
3 sets x 8-10 reps, rest 60s
Easier, harder & alternatives
Make it harder
Take care if…
- If you feel sharp pain in your back, stop the movement immediately.
- If you have a history of back discomfort, choose a gentler option like a basic leg lift.
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
Should I feel this in my lower back?
You should feel this primarily in your abdominals. If you feel strain in your lower back, keep your legs at a lower angle or reduce the range of motion.
Can I do this if I don't have a mat?
Yes, but ensure you are on a flat, firm surface like a rug or carpet to keep your spine comfortable.
How often should I practice this?
2-3 times per week is a great starting point for beginners to build core consistency.