Workout Sandbags filler bags do NOT leak. They have been proven so by pro and college teams, gyms, boxes, and individuals from here to there. They are of an original design that holds all of the sand capacity of the outer bag in one filler bag. This is done to allow the sand to shift as a whole with the outer bag. This gives you the best sandbag training workout. We highly recommend getting our filler bags with the same size outer bag for any team, gym, box, or any other commercial usage that has many people a day using it. For individuals who will be using it themselves only at home, it is an option to go with contractor bags. But for the optimum sandbag training effect, even home users will do best with our filler bags.
Above photo taken at CrossFit Games of our "Snake" bag in action. These bags are made the same as our filler bags, but are longer and slimmer.