[Barefoot runners wearing tunics take part in a footrace in the ancient stadium of Nemea, southwest of Athens on Saturday, June 11, 2016. Fifty-five days before the Games begin in Rio de Janeiro, participants from around the world are taking part in very different kind of sporting tournament. The races, only include a 90 meter sprint on a straight dirt course at the 2,300-year-old stadium and a 7.5 kilometer run through fabled olive groves and vineyards, where in ancient Greek mythology Hercules, god of strength, sport and fertility, slayed a fearsome lion. (AP Photo/Yorgos Karahalis)]NEMEA, Greece (AP) — Fifty-five days before the Games begin in Rio de Janeiro, athletes from around the world are taking part in a no-frills Olympics: No national teams. No medals. No shoes.