Ibtihaj Muhammad, the Muslim fencer from Maplewood, New Jersey, faces as much as $20,000 a year in expenses to participate in her sport, for example. So she and other athletes have to get their money from a wide-ranging network of private entities, nonprofits, generous businesses, sponsors, family support, and everyday donations.

“There are a few people at the top who have true brand power, and can move product and make a difference for a brand,” Jack Wickens, a board member of the USA Track & Field Foundation, told The Week. “And they get paid pretty well. But the pyramid is very steep.”

Sponsorship numbers can be hard to come by. But in an interview with The Week, Adam Nelson — a gold medal shot putter who went to the 2000, 2004, and 2008 Olympic Games — estimated that maybe 100 to 120 athletes globally are able to make over $15,000 from their sponsorships.

Those opportunities can also come and go, as corporate interest waxes and wanes. The result is an often cutthroat sponsorship environment. Even those athletes who do get sponsors can, perversely, find their duties eating into their training. (The hardships athletes often face making a living after their Olympic days are done is a whole other topic.)