Jackknife Sit-up
A guide to the Jackknife Sit-up. A bodyweight strength exercise to target the ab muscles.
| Main muscle worked | Abs |
| Equipment | Bodyweight only |
| Mechanics type | Compound |
| Also known as | Jackknifes |
How to do Jackknife Sit-ups
- Lie flat on the floor with your arms fully extended back behind your head and you legs straight.
- Bend at the waist and contract your abs whilst simultaneously raising your legs and arms to meet in a jackknife position above your stomach.
- Lower your arms and legs back to the starting position and repeat.
Beginning the Jackknife Sit-up
If you can't yet perform the Jackknife Sit-up try starting with the standard sit-up first or the plank and build up abdominal strength before progressing.
Advanced Jackknife Sit-ups
If you're starting to find the jackknife exercise particularly easy you can try introducng additional weight to the exercise. Holding a weight or medicine ball between your feet is an intense and effective technique for a seriously intense ab workout.
Disclaimer
Always consult your GP before undertaking any form of weight loss, fitness or exercise