If the modern Olympic Games ran true to the strict customs of ancient Greece, they might well today have been called the "Naked Games". From the early 8th century BC, Olympic athletes competed in the nude. There are indisputable records going back to Athenian philosopher Plato in the 5th century BC and even Homer's Iliad, as well as many explicit drawings that confirm it was common practice for all male track and field athletes to take part naked. This included the often-dangerous sports of discus throwing, wrestling, boxing, and horse racing without protective clothing.
There was a version of protection used by the Ancient Greeks, but one that would be odd to us today to be considered much protection. To protect the penis during wrestling matches and other contact sports, the men would tie a string known as a kynodesme around the tip of their foreskin enclosing their glans, thus keeping the glans safe. The kynodesme could then either be attached to a waist band to expose the scrotum or tied to the base of the penis so that the penis appeared to curl upwards.
The only exception to the nudity rule seems to have been for charioteers, who wore long white tunics. The words gymnastics and gymnasium are based on the Greek adjective gymnos, which means lightly-clad or naked. For non-charioteers, the only adornment on the athletes' bronzed, muscular torsos would have been the gleam of olive oil with which they ritually anointed themselves.
Some historians have believed that the reason for competing nude was to make sure that women did not compete. According to one legend, it was discovered that a woman had competed and won, so it was decreed that athletes would compete nude from that point on to make sure that only men competed in the Olympics. It was also said that this was done to make sure that non-Greeks, particularly Jews or others who practiced circumcision, could not compete. Only a man who was uncircumcised was allowed to compete.
According to Dionysius of Halicarnassus, a writer in the 1st century BCE, Greek athletes did not compete in the nude until the 15th Olympiad in 720 BCE, more than 2700 years ago. That was more than half a century after the birth of the first Olympic Games, which originated in Olympia, in southern Greece, in 776 BCE. A Spartan runner named Acanthus was said to have set the fashion by appearing without the customary loincloth. Two hundred years later, the origin of this practice of nudity was attributed to another sprinter, Osippus, who won the one-stade footrace (about 200 yards) at the Olympics of 720 BCE. It was said he realized that a naked man could run faster than one impeded by a loincloth.
In the 7th century CE, more than 1300 years later, writer Isidore of Seville suggested that during a race in Athens, one of the runners had the bad luck to trip over his own loincloth when it slipped down. A magistrate in charge of the games ordered a new ruling that athletes should compete in the nude. The historian Thucydides, who lived at the end of the 5th century BCE, wrote that it was the "Spartans who were the first to play games naked, to take off their clothes openly and to rub themselves down with olive oil after their exercise. In ancient times even at the Olympic Games the athletes used to wear coverings for their loins and indeed this practice was still in existence not very many years ago."
Women were not completely excluded from the Olympics. While married women were not allowed to participate in, or to watch, the ancient Olympic Games, unmarried women could attend the competition, and the priestess of Demeter, goddess of fertility, was given a privileged position next to the Stadium altar. During the classic period in Greece (500–323 BCE), women were allowed to participate in sporting events in Sparta, and there were two other events for sportswomen from other parts of Greece, Athens and Delos.
The closest thing to a women’s version of the Ancient Olympics were the Heraean Games, a separate festival honoring the Greek goddess Hera, which was held to demonstrate the athleticism of young, unmarried women. The athletes, with their hair hanging freely and dressed in special tunics that cut just above the knee and bared their right shoulder and breast, competed in footraces. The track shortened to about one-sixth the length of the men’s track in the Olympic Stadium. It’s uncertain if men were barred from these all-female races. Little is known about this festival other than what was written by Pausanias, a 2nd century CE Greek traveler. He mentions it in his description of the Temple of Hera in the Sanctuary of Zeus and says that it was organized and supervised by a committee of sixteen women from the cities of Elis. The festival took place every four years, when a new peplos, a body-length garment established as typical attire for women in ancient Greece, was woven and presented to Hera inside her temple.
It wasn’t that women were discouraged from sports in general; physical fitness was highly valued by women in Greece. A few women have been documented driving chariots, owning horses that won Olympic competitions, swimming, juggling, performing acrobatics, and potentially even wrestling. Spartan women were well-known for promoting physical education, believing good fitness assisted in healthy childbirth. By the first century CE, female athletic competitions were common under the Roman Empire. The first woman recorded to have won an event in the Olympics was Kyniska (or Cynisca) of Sparta, the daughter of Eurypontid king, Archidamus II, and the full sister of King Agesilaus (399–360 BCE). She won the four-horse chariot race in 396 and again in 392.