How can you get athletes foot?

Contact. Athlete's feet is a fungal infection that comes from contact with a surface that has fungus on it. Usually a damp, porous surface like gym floor, pool deck, shower floor and even other people's shoes!
Fungus is. Ubiquitous, meaning it can be found almost anywhere. It particularly likes dark wet, environments, and under a toenail which resides in a sock in a shoe is a perfect breeding ground. As is the skin on the feet.
Exposure. Working barefoot on infected tiles in a locker room or bathroom where someone else with fungus has spread the fungus. Also from pedicure where the instruments or foot bath has not been disinfected. Treat early to prevent it from spreading.

Related Questions

How can you get rid of athletes foot in children 3 & 4 yrs?

Antifungal creams. Tinea pedis, or athlete's foot, is caused by a fungus (often by t. Rubrum fungus) that can be on locker room floors or other people's footwear. If the fungus is able to take hold on the skin cells and start growing, one will get the athlete's foot rash. Tinea pedis should be treated to relieve symptoms and also to prevent it from spreading to the toenails. Lotrimin (clotrimazole) af cream works for all ages.
Athlete's foot. First, it's important to keep their feet dry, especially between toes. Avoid sweaty or wet socks as much as possible. It's good to have at least 2 pairs of shoes so they can dry out for a day between wearings. Several nonrx creams are available, like clotrimazole, miconazole, terbinafine, and others. They're applied sparingly twice a day.
Topical antifungals. You have to be careful to make sure which are okay for kids. Some have studies with kids - others do not.

Is it possible to get athletes foot in one day?

Yes. If exposed to it the fungus can get into the skin in a day.
Yes. Exposure can lead to an infection, however it may take several days for you to become symptomatic.

Can I get/catch athletes foot through your sock?

Yes. If you have a fungus and don't practice good hygiene it's possible. Need to wash socks and never where same pair to days in a row. Try some otc anti fungals like lotromin ultra or see your podiatrist. Fungus likes to grow in dark damp, moist environment.