Cows rush through mud and water while jockey holds onto their tails, on March 12, 2016 in Padang, West Sumatra, Indonesia. For hundreds of years these farmers have competed in one of the worldís most oddest races in the hopes of showing off their cattle. Known as Pacu Jawi the traditional cow race takes place in Padang, West Sumatra, and has become the highlight of the year for locals. (Photo by Teh Han Lin/Barcroft Images)

Melissa Stewart's team competes in the official restart of the Iditarod, a nearly 1,000 mile (1,610 km) sled dog race across the Alaskan wilderness, in Fairbanks, Alaska, U.S. March 6, 2017. (Photo by Nathaniel Wilder/Reuters)

Ahmed, a 10-year-old jockey, looks on during the opening of the International Camel Racing festival at the Sarabium desert in Ismailia, Egypt, March 21, 2017. (Photo by Amr Abdallah Dalsh/Reuters)

Participants arrive at the finish line during the annual Maldon Mud Race in Maldon, east England on May 7, 2017. Originating in 1973, the race involves competitors racing around a course through the River Blackwater in Essex at low tide. (Photo by Daniel Leal-Olivas/AFP Photo)

A participant competes in the “Nostalgic Ski Race” in the western town of Neuastenberg February 8, 2015. The “Nostalgic Ski Race” is held every two years with about 40 participants and is organized by the ski club of Neuastenberg, a town which was founded in 1713. The conditions for the participation in the race are vintage skis and dresses. (Photo by Ina Fassbender/Reuters)

Participants compete during the Strong Race event near Tukums, Latvia, May 3, 2015. More than 4,000 people participated in this 9 km endurance race with 33 different obstacles. (Photo by Ints Kalnins/Reuters)

A cloud of black smoke billows out the exhaust pipe of John Robertson's diesel dragster as he runs down the track during the 2015 NHRA Kansas Nationals, Friday, May 22, 2015, at Heartland Park in Topeka, Kan. (Photo by Chris Neal/The Topeka Capital-Journal via AP Photo)

Sebastien Bourdais, of Colombia, makes a corner during practice for the IndyCar auto race Saturday, June 13, 2015, in Toronto. (Nathan Denette/The Canadian Press via AP)