The Knee Lift strengthens your lower abdominal muscles, helping you keep your pelvis and back stable.
Lie on the floor with both knees bent. Put your feet flat on the floor and your arms by your sides. Tighten your abdominal muscles.
Lift one bent knee and move it toward your upper body. Make sure you tighten your abdominal muscles before you lift your knee, and keep your abdominal muscles tight and your back flat on the floor.
Hold for 10 seconds.
Repeat three times.
Then, switch legs.