The seated knee tuck "engages and strengthens the innermost core muscle, the transverse abdominus (TVA), that wraps around your torso," said NASM-certified personal trainer Chris Lee of Hau.fit. You can either hold the tucked position for a tough isometric move, or perform reps as explained below.
- 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.
Image Source: POPSUGAR Photography / Tamara Pridgett