Jackknife Sit-Up
Exercise Data
Main Muscle Worked: Abdominals
Other Muscles Worked: None
Equipment: BodyOnly
Mechanics Type: Compound
Tips: Lie on the floor on your back. Place your arms straight back behind your head. Bend at the waist while raising your legs and arms to meet in a jackknife position. Lower arms and legs back to the starting position. Keep your elbows and knees locked!