Body Solid Tools - Medicine Balls. The ball"s in your court for upper body, lower body and core exercises! Body Solid Tools Medicine Balls add resistance to a variety of exercises and can be used to activate and strengthen core muscles that can be difficult to target during traditional training routines. Body Solid adds a textured grip and adjustable air pressure to bring modern functionality and flexibility to time-tested medicine ball exercises. Body Solid Tools. A good fit for your life. A great fit for your space.