The documentary Back On Board follows the career of four-time Olympic champion Greg Louganis. HBO hide caption

itoggle caption HBO

Concerns about pollution in the waters around Rio have prompted the world sailing federation to take action ahead of next year's Olympic Games. Here, garbage is seen on Bica Beach, on the banks of the Guanabara Bay, with the Sugar Loaf mountain in background, earlier this year. RICARDO MORAES/Reuters /Landov hide caption

itoggle caption RICARDO MORAES/Reuters /Landov

The Olympic flag flutters near the Cauldron at the Olympic Park during the 2014 Sochi Winter Olympics. Adrian Dennis/AFP/Getty Images hide caption

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"Rowdy" Roddy Piper, clad in his trademark kilt, speaks in 2009 at the WrestleMania 25th anniversary press conference at Hard Rock Cafe in New York City. Piper fought in the main bout at the first WrestleMania in 1985, losing a tag-team match to Hulk Hogan and Mr. T. Andrew H. Walker/Getty Images hide caption

itoggle caption Andrew H. Walker/Getty Images