How hard do you want your heavy bag?

the cloth in my heavy bag has sunk towards the bottom, so i'm looking around the net for ideas of how best to fix it up.

i read that you should try to redistribute it by hanging it the other way and shaking it. the guy who wrote the article then said that you don't want to fill it too much because it messes up your wrist joints and gives early arthritis.

i want it as hard as it goes to toughen my wrists and make my strikes stronger, but now i'm hesitant because i don't wanna damage my wrists long term.

does anyone in the ug have some advice or experience they can share on this?