Starting Position
1. Grab a pull-up bar with both hands shoulder-width apart.
2. Let your body hang fully so your arms are completely extended.
3. Keep your legs naturally together.
During the Exercise
1. Use your abdominal muscles to lift your knees towards your chest.
2. Slowly lower your legs back to the starting position.
Breathing Tips
Exhale as you lift your knees, and inhale as you lower your legs.