Athlete's foot back again every time I start using the gym

Every time I get back into going to the gym regularly, within about a month I have itchy, flaky skin between my toes again. Then I stop going for a while, it clears up, and the whole cycle starts over the next time I get motivated.

I do use the cream from the pharmacy and it does work, so it is not that the treatment fails. It just always comes back. I shower at the gym most days and I change my socks.

Is there something obvious I am not doing? I would rather fix the cause than keep buying the same tube four times a year.