Bintiva Slam Balls Slam balls can be used for standard weight-lifting exercises in place of dumbbells, or kettlebells, and for dynamic exercises that cannot be obtained with traditional gym equipment. They are a great addition to any gym because they are so versatile and durable. The Bintiva Slam balls are designed to withstand hard impacts from throwing exercises. Throwing exercises are seen as effective for athletic training because they build strength in the core, back, leg, and shoulder muscles. These exercises also improve cardiovascular endurance and hand-eye coordination. Professional Grade-Bintiva slam balls are manufactured from professional grade materials, and are designed to withstand the most rigorous routines. High Density - The slam ball is sand filled, and is designed to prevent the ball from bouncing off surfaces Strength Builder - The slam balls are recommended by health and fitness professionals for building strength in the core, back, leg, and shoulder muscles.