Seated Knee Tuck
If you want to get more ab definition, you've got to work your rectus abdominis muscles (aka the six-pack muscles). This move will definitely sculpt your abs.
- Start seated on the ground or on a weight bench. Place your hands about an inch behind your back with your fingers facing forward. Your feet should be on the ground.
- Lift both feet up off of the ground and extend both legs as you simultaneously lower your upper body. Be sure to get full extension at your hips and legs.
- With control, bring your legs back to your chest without touching the ground with your feet and return to the starting position.
- This counts as one rep.