Take crunches, bridges, push ups, squats and planks to the next level with the Lifeline 65 cm Exercise Ball by continually engaging your core and back muscles for improved strength and balance. Perfect for rehabbing, warming up and stretching or as a support tool to break plateaus in resistance and HIIT workouts, the exercise ball helps train and build the stabilizer muscles needed for functional strength and athletic performance. Lifeline 65 cm Exercise Ball Grey - Hand Exer. Equip. at Academy Sports