When Michael Phelps carries the flag into the Olympic opening ceremony Friday, the oversized pony logo on his blazer will be the most obvious giveaway that there’s more at stake for the country than loads of gold medals.

He and the other members of Team USA will be a walking advertisement for U.S. fashion and apparel — in this case, Ralph Lauren, which designed the uniforms.

Over the next 16 days, the Olympics will be a global stage for brands to showcase the latest styles and technical innovations. The teams’ apparel choices may drive shopper traffic at a time when many Americans are more likely thinking about their final trip to the beach rather than a new Polo shirt or pair of running shorts.

For sports apparel retailers, “the Olympics are the new fashion week runway,” says Simeon Siegel, retail analyst with Nomura.

Nike, the official sponsor for the United States Olympic Committee, has more than 100 Team USA products for sale, plus more specialized merchandise such as the jackets athletes will wear on the medal stand. Stores will have Olympics gear front-and-center as the games get underway. Under Armour launched a “country pride” collection that includes T-shirts with phrases such as “Home of the Brave” and sports bras emblazoned with “USA.”

Retailers such as Dick’s Sporting Goods will have specific Olympics displays in stores. Macy’s, which has an exclusive partnership with Ralph Lauren to sell the opening and closing ceremony outfits, expects a surge in traffic this weekend after the athletes make their entrance in Maracana Stadium in Rio de Janeiro.

“Historically, as soon as the Olympics start we see a huge lift,” says Tim Baxter, Macy’s chief merchandising officer. That goes for athletic apparel too, particularly in the kids department as impressionable youngsters are inspired by Olympic competitors, Baxter says. Red, white and blue options will be especially popular, he says.

This Olympic year, the potential benefit for retailers may be more significant, as interest in athletic apparel has boomed. Sportswear and so-called “athleisure” clothing — casual and comfortable pieces that can just as easily be worn to happy hour as to the gym — have become big sellers at a time when the industry has otherwise been in a lull.

Sales of athletic apparel for the year ended May 31 spiked 14% to $45.7 billion, according to data from NPD Group. That follows a 15% rise in sales in the year prior. Meanwhile, total apparel sales in the U.S. in the past year were flat, at $214.4 billion.

Still, some say it’s difficult to determine a measurable impact from the Olympics. Macy’s and Dick’s declined to comment on how much the Olympics will contribute to overall sales. Nike said it doesn’t break out Olympics sales.

“It’s a great way to showcase products, but not one that turns into immediate sales,” says Matt Powell, sports industry analyst with NPD Group. “I have never seen the Olympics themselves get people up off the couch to go buy something.”

That won’t stop brands from putting their most sporty foot forward. It will be an especially influential games for Under Armour, the Baltimore-based company that’s made a rapid climb to recognition in recent years within the U.S. sports apparel industry. Under Armour sponsors Phelps, who’s won more Olympic medals than anyone in the world and is competing, and expected to medal, in three individual events in Rio. The company has also been angling to make a bigger name for itself outside the U.S.

“We hope to see an increased interest in the brand that translates to sales,” says Kevin Eskridge, senior vice president of global merchandising for Under Armour. “Anytime a large audience is focused on a global sporting event, it provides us with a great opportunity to broaden our consumer base.”

The Olympics can sometimes backfire on brands though, as they did for Under Armour during the 2014 Winter Games in Sochi after U.S. speedskaters complained that their Under Armour suits were to blame for their lack of medals in the competition. Under Armour was forced to play defense after touting the the uniforms as the fastest suits in the sport.

Some athletic gear makers, however, don’t prioritize the games. Adidas isn’t making a big push to sell Olympics-related merchandise and says soccer events like the FIFA World Cup and Copa America are more influential to Adidas sales than the Olympics.

But the company still recognizes the event as crucial to brand recognition and sponsors hundreds of athletes competing in Brazil.

“Having a presence and good visibility during the Olympic Games ensures that consumers are more likely to buy products from our brand afterwards,” says Adidas spokeswoman Maria Culp.

Follow Hadley Malcolm on Twitter @hadleypdxdc.