When the Olympics open in Sochi later this week, a select few U.S. Olympians will be arriving with multimillion-dollar endorsement deals and promises of more fame and fortune to come.
But many of the nation's greatest athletes will be competing for love—and just hoping to scrape together enough money.
"There [are] very few people in curling for the money," said Allison Pottinger, 40, an Olympian who figures she may break even on the costs of competing this year.
"At best it's a zero sum [game], but there are so many things you gain that aren't monetary," she said.
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Pottinger will have plenty of company on the U.S. Olympic team. Many of the nation's top athletes are fulfilling their Olympic dreams thanks only to hard work and a mishmash of scant funding through athletic associations, small sponsorship deals and the generosity of family, friends and even strangers.
"It's a little bit of everything," said Doug Blais, a sport management professor at Southern New Hampshire University.
For some athletes competing in more obscure sports, even a place on the podium won't guarantee a payday.
"Even if they win gold, there is no pot of gold," Blais said.
That may come as a surprise to Americans watching the games on television and used to seeing the faces of high-profile athletes like Shaun White. His sponsor, GoPro, built him a private half-pipe, and his business ventures include an eponymous line of clothing.
While there's no question that White and other celebrity athletes have a passion for their sport, experts say it can be surprising to find out how difficult it is financially for some athletes to even get to the Olympics.
"It is really a disconnection between the enormous value of the games compared to the degree to which some portion of the competitors really continue to do this for love and not for money," said Ellen Staurowsky, a professor of sport management at Drexel University.
This year, Staurowsky said, many athletes turned to online fundraising sites like RallyMe and GoFundMe to ask friends and strangers for help, often in return for a personalized thank-you, poster or other trinket.
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The monetary struggles can be particularly tough for those who must train for years to reach the Olympic level and may be competing against athletes from countries whose governments provide funding or more generous sponsorship deals.
In Europe, the biathlon is among the most popular winter sports, said Max Cobb, president and CEO of the U.S. Biathlon Association.
In the U.S., however, the sport has been slower to catch on—and harder to make a living at. Cobb said the best American biathletes get a maximum stipend of $2,000 a month. They can receive extra money or get sponsorship deals if they win or place well in competitions.
Still, Cobb said, few U.S. biathletes are getting rich off the sport, and many spend their 20s and 30s competing instead of establishing themselves in another career.
"It's very impressive—the commitment that the athletes are willing to make just for the sake of success in the sport," he said.
Though the financial strain can put extra stress on athletes, Cobb said, the struggles also seem to bring the team closer together.
U.S. Olympian Lowell Bailey, 32, said being a full-time biathlete does sometimes mean getting a bit creative about funding, but he feels fortunate to have been able to make a career of it.
After all, he added, he wasn't looking to become a millionaire.
"It's never been why I do the sport," he said. "Honestly, I just love the sport of biathlon."
Pottinger said the curling association gives her team some funding to help cover travel and other expenses. It also gets in-kind donations, such as hotel discounts or donated uniforms, and some modest sponsorship deals.
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The "sponsorships definitely have a lot fewer zeroes than the other sponsorships you see," she said.
That means Pottinger, who is married with two young children, has to make a living at something else. She works in consumer insights for General Mills and uses vacation time and leaves of absence for competing. She squeezes in practice time and workouts late at night, early in the morning or whenever she can take a long lunch break.
She has no regrets, though.
"I was thinking about that the other night," Pottinger said. "I was leaving for practice late and it was cold, and I was like, 'You know what? It's worth it.' "
—By CNBC's Allison Linn. Follow her on Twitter @allisondlinn and Google or send her an email.
