absband
band jack knife sit-up
band jack knife sit-up is a common strength training exercise. Below are form tips, steps, and demos.
Steps
Step 1. Lie flat on your back with your legs straight and your arms extended overhead, holding the band.
Step 2. Engage your abs and lift your legs and upper body simultaneously, bringing your hands towards your feet.
Step 3. Pause for a moment at the top, then slowly lower your legs and upper body back down to the starting position.
Muscles & body parts
Primary muscles
abs
Secondary muscles
hip flexors
Primary body parts
core
Common mistakes & warnings
Form & control
Avoid momentum and excessive swing; keep core stable; match breath to movement; control the eccentric phase.
Control breathing and core; keep a steady tempo.
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