Incorporating Gaiam's Strong Core and Back Kit into your weekly workouts will help you build up a stronger, healthier back and firmer midsection. The unique peanut-shaped ball is key to helping engage your core more efficiently with every exercise. Stretch and strengthen your spine while increasing your range of motion. Included in the kit is the anti-burst CoreFit Ab Ball that's free of 6 of the most harmful phthalates and a pump. The kit also comes with a DVD containing 2 10-minute workouts: “Core Focus” targets those hard-to-reach places helping you build strength throughout your midsection; “Strong Core and More” adds more challenge with standing moves requiring greater control and concentration. Plus, the bonus feature, “Back Pain Relief,” delivers a 10-minute stretch routine.