Having been in the fitness arena for decades, sandbags have been proved to be an effective way to train. The filler sand inside shifts and moves when you move, giving your clients a much more dynamic and challenging training regimen. If you ask someone to throw a kettle bell you will likely be left with a broken kettle bell, a dent in your floor, and possibly an injury. With sandbags, all of that goes away. Sandbags are a live weight, meaning it moves with the movement, instead of a stiff, dead weight. You also have the ability to ask for multiple exercise drills to be done while standing in one position.