Training and competing were done in the nude. Athletes would coat themselves in olive oil during training and competition, and scraped it off at the end. This used olive oil was highly valued by the Ancient Greeks for magical purposes.
The main games were intended for men only. Women were barred from competing with the men, though they were allowed to sponsor athletes and own animals. There were games held for women, but they were not as popular. Married women were not allowed to watch the games. Unmarried women and the Priestess of Demeter were allowed to attend some of the events and watch most of the competitions.
Today the Olympic Games are certainly the most well-known of all the ancient cometitions, though there were other games as well. The four main games in Ancient Greece were the Olympic Games, the Pythian Games, the Nemean Games, and the Isthmian Games.