Constructed from high-quality, durable material, the Aktiv® Stability Ball is a great tool to increase core stability, posture, balance and flexibility. Use it for exercises such as sit ups, push-ups, squats. planks, hamstring curls and hip lifts. The unbalanced surface forces deep stabilizing muscles to engage throughout every movement, effectively enhancing and increasing muscle tone all over. The Aktiv® Fitness premium line of functional exercise tools inspire and support today’s high-demand dynamic training environments.