Core Training Ball. 300 calories. Perfect Ab Crunches Every Time. Targets All of the Ab Muscles- Upper, Lower and Side. Build core strength and increase flexibility. The Core Training Ball properly postitions your body for the perfect Ab crunch. Helps build core strength and increases your body's flexibility. 9" Latex-Free inflatable Ball. Straw for quick inflation. Non-slip texture for stability. Benefits: The Core Training Ball puts your body in the ideal position for doing Ab crunches and lower back exercises. Lying on the ball gives you a greater range of motion to strengthen your muscles for flat sculpted abs. The most effective fitness routine combines strength, cardio and flexibility exercises. Target training by Valeo can help you create a personalized fitness program that suits your needs. What's your ultimate goal -firming up, losing weight, building muscle? The fitness tools in our Target Training system are grouped by color and designed to work together.