Ancient Greek athletes competed and trained completely naked in front of huge crowds.

The tradition of competing naked likely started at the 15th Olympic Games in 720 BC. A runner named Orsippus of Megara reportedly lost his loincloth during a race and won because he could move more freely. After that, male athletes decided that being naked was the best way to compete.Before training, athletes covered themselves in olive oil. This wasn't just for looks. The oil helped protect their skin from the hot sun and kept them from losing too much water through sweat. It also made their muscles pop, which was important because the Greeks believed physical beauty was linked to being a good person.The gymnasium was the heart of the city where people exercised and talked about big ideas. Every gym had a special room called an 'apodyterion' where athletes would take off their clothes. Researchers from the University of Pennsylvania found that being naked in public actually motivated people to stay in shape. This naked tradition lasted for over 1,000 years until the games were stopped in 393 AD.