From gymnastics to track, soccer to sailing, the Games are a showcase for the world's greatest athletes. Some are first-time Olympians like Simone Biles, a 19-year-old gymnast from Texas. Standing at just 4 ft. 8 in, she has won the past three world championships and is favored to lead the U.S. women to another team gold.
Others are veterans, including U.S. swimmers Michael Phelps, the most decorated Olympian of all time, and Katie Ledecky, 19, who made history last summer at the World Championships as the first to swim, and win, all four freestyle -distances—200 m, 400 m, 800 m and 1,500 m—at the same meet. They are just three of the people you'll meet in our 60 Athletes to Watch in Rio guide.