When Olympic athletes strive to set sporting records, they are not only representing their country but also often advertising the brands that make the running shoes or swimsuits they compete in and the tracksuits they wear while not performing.

The sportswear brands which pay Olympians to market their clothing and footwear, say that their high-tech products improve performance, while at the same time trading off the star power of some athletes to market fashion apparel and shoes.

Because billions of people around the world will be watching these brand ambassadors, what they wear during the Olympics is highly regimented, leading to complicated wardrobe changes.

Where, when and why?

When competing, Olympic athletes wear clothing made by the brand sponsoring their sport’s national federation.

For example, Chinese volleyball players will wear Adidas when on the court, as the German sportswear brand sponsors the China Volleyball Association.

Most athletes competing at the Olympics are not household names and do not have individual sponsorship deals. Where an athlete does have a personal sponsorship contract, they will typically wear that brand’s shoes while competing, even if their outfit is by a different brand.

During the opening ceremony, in the Olympic Village, and on the podium, athletes’ outfits are determined by the brand sponsoring their country’s National Olympic Committee.

For example, Jamaican athletes at the Olympics wear Puma on the podium, because it is the official partner of the Jamaica Olympic Association.

For athletes, these rules mean multiple outfit changes during the event.

As an Adidas-sponsored athlete, German sprinter Gina Lückenkemper will compete in Adidas shoes, but she will wear Nike clothing, because Nike sponsors the German Athletics Association. If she wins a medal, she will wear an Adidas outfit on the podium, because Adidas is a partner of the German Olympic Committee.

It can get even more complicated.

French middle-distance runner Rénelle Lamote will wear Adidas clothing in the competition because Adidas is the official partner of the French athletics federation.

As a Nike athlete, she will compete in Nike shoes but in the Olympic village and on the podium, she will wear Le Coq Sportif, the French brand which is the official supplier for France at the Olympics.

(Reporting by Helen Reid; Editing by Alexander Smith)