A man demonstrates outside Republican presidential candidate Donald Trump's news conference at Trump Tower in New York, U.S., May 31, 2016. (Photo by Shannon Stapleton/Reuters)

Participants run through coloured powder during the YARKOcross colour run race in Almaty, Kazakhstan, June 5, 2016. (Photo by Shamil Zhumatov/Reuters)

Spunky runs during the third heat of a dog race Monday, September 1, 2014, at Canterbury Park, in Shakopee, Minn. Canterbury Park hosted their annual Labor Day Wiener Dog Wars in which dogs competed in seven races on the horse track for the title of Grand Champion. (Photo by Jeff Wheeler/AP Photo/The Star Tribune)

A man dressed as zombie takes part in a zombie race to raise funds for children with cancer at the child Hospital Manuel de Jesus Rivera in Managua October 19, 2014. (Photo by Oswaldo Rivas/Reuters)

Dustin Murley (L) and Jessey Sisson race on their ostriches during the annual Ostrich Festival in Chandler, Arizona March 10, 2013. (Photo by Joshua Lott/Reuters)

Participants take part in an extreme run “Bison race” near the town of Logoisk, Belarus September 17, 2016. (Photo by Vasily Fedosenko/Reuters)

A participant competes in the “Farinato Race” winter extreme run competition in Gijon, northern Spain, January 31, 2016. (Photo by Eloy Alonso/Reuters)