A female swimmer reacts after finishing the competition in a pool carved from thick ice covering the Songhua River during the Harbin Ice Swimming Competition in the northern city of Harbin, Heilongjiang province, January 5, 2016. The swimming competition was held on the official launch day of the Harbin International Ice and Snow Sculpture Festival. (Photo by Aly Song/Reuters)

Elise Graham takes part in the World Bog Snorkelling Championships 2017 with a rubber duck on her back on August 27, 2017 in Llanwrtyd Wells, Wales. The competition draws competitors from all over the world and is now in its 32nd year. (Photo by Matthew Horwood/Getty Images)

Regina Halmich and Sergiy Plyuta perform during the 'Let's Dance' TV show at Coloneum on March 23, 2011 in Cologne, Germany.

A woman takes part in an extreme run competition in Zhodino, east of Minsk, September 26, 2015. (Photo by Vasily Fedosenko/Reuters)

The Economic and Social Research Council (ESRC) has announced the winners of a UK national photography competition in which we challenged young people aged 14–18 for their unique take on society and the social sciences by asking them to take a picture on the theme of “Where Do I Belong?” – ESRC Press Office. Photo: “Society hurts”. (Photo by Grace Ridge/ESRC)

Nic Lamb rides a wave during the third heat of the first round of the Mavericks Invitational big wave surf contest Friday, January 24, 2014, in Half Moon Bay, Calif. (Photo by Eric Risberg/AP Photo)

Children, wearing traditional Bavarian folk costumes specific to their region, prepare for the competition in the “Schuhplattler” style of Bavarian folk dancing for the Bavarian Lion Award at the Huosigau Heimat and Folklore Society on May 28, 2011 in Weilheim, Germany. (Photo by Johannes Simon/Getty Images)

Jordanian soldiers pose after the opening ceremony of eighth annual Warrior Competition at the King Abdullah Special Operations Training Center (KASOTC) in Amman, Jordan, May 2, 2016. Twenty Seven Teams from Eleven countries are participating in a competition to test their military skills. (Photo by Muhammad Hamed/Reuters)