Jackknife Sit Up
Trains the abdominals. No equipment needed. None of our programs use it yet, but you can add it to any session you build.
Free to use. The app works out every weight and times your rest.
In the programs
None of our programs use the Jackknife Sit Up
It is in the app, so you can add it to any session and log it like anything else. It is just not written into one of our 50 free programs. If you want a abdominals exercise that is, there are 9 on the Abdominals page.
Muscles worked
What Jackknife Sit Up trains
Technique
How to do the Jackknife Sit Up
- Lie flat on your back with your legs extended and your arms stretched overhead on the floor.
- In one motion, engage your core to lift your torso and legs simultaneously, reaching your hands toward your feet so your body forms a V shape.
- Pause briefly at the top of the movement.
- Lower your torso and legs back to the floor with control, returning to the fully extended position. Repeat for the desired number of repetitions.
Form cues
Getting it right
- Keep your legs as straight as possible and move both halves of your body in unison.
- Perform the movement with control rather than throwing yourself upward with momentum.
- Exhale as you fold into the V position and inhale as you lower back down.
- Bend your knees slightly if you cannot reach your feet with straight legs.
Substitutes
Swap Jackknife Sit Up for
The app's swap picker ranks these the same way: same muscles, similar movement, similar equipment.
Let the app run the Jackknife Sit Up for you
Durata picks the weight, times your rest and adds load when you earn it. That works on any of our 50 free programs, or on a session you put together yourself.