Intermediate Isolation Core
Bench Jack Knife
Sit on bench edge, lean back and bring knees to chest simultaneously
Looping
HD video demonstration • Hover for controls
Primary Muscles
Abs
Secondary Muscles
Abs
Equipment Required
Flat bench
How to Perform
Sit on edge of flat bench, lean back slightly with hands gripping bench behind you. Draw knees toward chest while leaning back, then extend legs.
Form Cues
- Sit on edge of bench
- Lean back slightly
- Bring knees to chest
- Extend legs and lean back
Track This Exercise in RoyalFit
Log your sets, reps, and weight. Track your progress and hit new PRs with personalized workouts.
Download on App Store