The core disk is an excellent way to add a new level of difficulty to your workout. You can use this soft disk in Pilates, yoga or regular workouts to work your core muscles and increase balance and stability. You can easily inflate or deflate it to change the level of difficulty. You can also use it for push-ups, sit-ups and much more. The disk comes with a Core Performance training DVD, featuring Mark Verstegen from Athletes' Performance, the trainer to world-class athletes and author of the book, Core Performance. 13 inches in diameter.

(DVD) approx. 30 mins.