Because stretching and strengthening the torso is a crucial element in so many athletic endeavors, the Weight Ball is an ideal piece of equipment. No other device works as many parts of the body simultaneously. It is easily the most versatile and probably the most important single training tool you can use. The Weight Ball excels at developing the torso for rotation and explosive power. Many of the newer weight ball products on the market have some distinct disadvantages.
Some balls require inflation of air.
Many times the balls do not stay fully inflated during use, decreasing their effectiveness and function. An added piece of equipment, the air pump is required. These weights can shift or if the covering breaks, you've got a mess to clean up and no way to fix this ball. Some balls don't bounce, decreasing the ways in which they can be used. An added piece of equipment such as a rebounder board may be required.