Olympic road cycling is a grueling, panoramic tour of Rio (The Associated Press)

Olympic road cycling races promise to be a grueling, 6-hour showcase featuring everything from the sun-splashed beaches of Copacabana and Ipanema to the squalor of the nearby slums. ”It’s the hardest course I’ve seen in a single-day race,” said American rider Megan Guarnier, who made a special trip to Brazil just to scout the course. Like the course in Rio, it then sent riders off into the countryside, though the elevation changes were nothing like they will face in Brazil.