The most significant difference between the Element Fitness Slam Ball and a medicine ball is that a slam ball is designed for throwing exercises. It has a harder shell typically made of a tough rubber so it can handle a high-velocity impact against a hard surface. Slam balls can be used for standard weight-lifting exercises in place of free weights and for dynamic exercises that involve an increased cardiovascular aspect. Slam balls are also effective for athletic training because they improve muscle mass, cardiovascular endurance and hand-eye coordination. Medicine balls are typically used only for standard lifting exercises because they are not meant to withstand impacts like slam balls do.