Elevating your running speed with the Adjustable Weight Resistance Trainer. Professional sandbag trainer weight resistance trainer for professional sprinter workouts. This sandbag trainer comes with 3 weight sandbags, each is about 0.22lbs. Adjust weight option for variable weight resistance. Adjustable leash waist belt length to accommodate athletes of any size. Very suitable for fitness enthusiasts and sprinter, enhancing their physical conditioning, as well as professional athletes focused on developing explosively power and strength. Adjustable weight trainer for sprinters, football player and other athletes strengthen lower-body to improve speed and explosiveness by forcing you towing weight in the bag. Widely used for gym floor, sport field, or any flat terrain where athlete engages in weight resistance sprinting exercises.