Easy to fill with PLAY SAND.
"Great exercise bag. Well made and soft enough not need gloves. I read Some reviews about being very difficult to put sand in the base. It took me 40 minutes to put 100 lbs play sand, clean the carpet and assembly the shaft on the base. I use PLAY SAND because it is dry and. Flow easily (do not use the cheaper sand for concrete, that does not flow), I use a flex funnel from Autoparts store for transmissions fluids and cut the first section to fit exactly in the base fill hole, and used a plastic large plastic cup. Tilt the base in 45 degree angle, hole funnel straight up and start filling with sand."
