they don't last very long. I play a lot of tennis and even though they don't wear down because they have an incredible amount of guard against wear and tear, the comfort diminished very quickly because the shoe became super stiff and the cushion just collapsed. I used them for about 30 hours and then trashed it even though the sole and the outside looked like it could last much longer because the cushion, comfort, arch support, all the soft parts diminished so quickly.