Abs exercise · body weight
Jackknife Sit-Up
The jackknife sit-up is a bodyweight exercise that targets the abs, with the hip flexors assisting.
- Target muscle
- Abs
- Also works
- Hip flexors
- Equipment
- Body weight
- Body part
- Waist
How to do the jackknife sit-up
- Lie flat on your back with your legs extended and your arms overhead.
- Engage your core and lift your legs and upper body simultaneously, reaching your hands towards your toes.
- Pause for a moment at the top, then slowly lower your legs and upper body back down to the starting position.
- Repeat for the desired number of repetitions.
Sets and reps
Start with 3 sets of 10–15 reps, resting 45–60 seconds. When every set feels easy, add reps, slow the lowering phase or move to a harder variation.
Muscles worked
The main muscle is the abs. The hip flexors work as secondary muscles. See all ab exercises or every bodyweight exercise.
