The MYO Slam ball design will build explosive strength, improve muscular endurance, increase speed and response time as well as strengthen and tone a wide variety of muscles including the glutes, quads, calves, hamstrings, biceps, triceps, deltoids, trapezius and core abdominalsThe MYO Strength Slam Balls are made with just the right balance of comfort, control and grit. Strong enough to endure the most vigorous of workouts.The soft rubber exterior is cushioned to prevent blisters and irritation, whilst the strong rubber lined interior is durable and reliable ensuring there will be less damage and the ball will keep its shape for much longer.