Jack Knife Floor
Description
The jack knife floor is a classic V-up ab exercise performed on the floor. The lifter starts flat on the back with arms overhead and legs straight, then lifts the legs and torso at the same time to meet in a V shape. The move loads the entire core hard.
Muscle Group
Equipment Required
Jack Knife Floor Instructions
- Lie flat on your back on the floor.
- Extend your arms overhead and your legs straight.
- Brace your core hard.
- Lift your legs and torso off the floor at the same time.
- Reach the hands toward the toes in a V shape.
- Pause at the top with the body folded.
- Lower the legs and torso back down with control.
- Avoid letting the lower back arch off the floor.
Jack Knife Floor Form & Visual
Jack Knife Floor Benefits
- Strong full ab builder
- No equipment needed
- Trains hip flexors
- Easy to scale
- Useful core finisher
- Builds abdominal strength
Jack Knife Floor Muscles Worked
- Rectus abdominis
- Hip flexors
- Obliques
Jack Knife Floor Variations & Alternatives
- V Up
- Toe Touch Crunch
- Hollow Hold
- Sit Up
