A sinking punching bag is annoying - the bottom is hard and the top is empty. I show you an effective filling method that stops sinking and gives a good shape.
SEEUTEK Ellis Boxing Bag Speed Trainer Swing Set Adjustable Height Training Boxing Bag with 12 oz. Boxing Gloves BZ-1260 - The Home Depot
A Guide to Filling a Heavy Bag, TITLE Boxing
Best way to make a heavy bag stand outdoors? - Community Forums
How to Fill a Punching Bag: 12 Steps (with Pictures) - wikiHow
How to Fill a Punching Bag: 12 Steps (with Pictures) - wikiHow
How to fill a punching bag - Punching Bag Factory
A Guide to Filling a Heavy Bag, TITLE Boxing
How to Hit the Heavy Bag Properly (So It will not Swing)
A 20-Minute Punching Bag Workout