This exercise provided courtesy of Billy Polson, founder and co-owner of DIAKADI Body, which was voted best personal training gym in San Francisco by CitySearch in 2006.
Knee tucks are more than an abs cruncher. The use of the stability ball trains your abs to have a greater degree of stability and control, while also improving your shoulder stability and endurance. For this variation on the exercise, you'll do the knee tucks with controlled speed, increasing the difficulty level.
Position yourself in a decline push-up position with your hands slightly more than shoulder-width apart on the floor and your shins and shoelaces resting on top of the stability ball. Your legs should be straight, your spine neutral, and your toes pointed.
- From the start-up position, bend your knees in towards your chest in a fast yet controlled manner. The ball will follow (see Photos 2 and 3).
- Once your knees are almost touching your chest, pause, and then reverse direction and extend your legs back to the starting push-up position. Keep you toes pointed throughout the exercise. Move in both directions as fast as you can go while maintaining form and control (see Photos 4 and 5).