Participants run at the “Half-Naked Marathon” at Olympic Forest park in Beijing, China, February 28, 2016. This annual running event which requires participants to run half-naked, was organized to promote environmentally friendly lifestyles. (Photo by Kim Kyung-Hoon/Reuters)

A genetically engineered featherless rooster struts around the campus of the Hebrew University of Jerusalem's Department of Agriculture May 22, 2002 in Rehovot, Israeli. After two years of research, departmental scientists announced the naked chicken, as it has been dubbed, as a low calorie bird because the lack of feathers means the chicken has less fat. It also matures earlier than its feathered counterparts. (Photo by Moshe Milner/GPO/Getty Images)

Runners cross the Verrazano-Narrows Bridge shortly after the start of the New York City Marathon in New York, November 2, 2014. (Photo by Lucas Jackson/Reuters)

This brave swimmer certainly has a brrracing workout each weekend she skinny dips in one of the coldest rivers in Europe which regularly plummets to temperaturess of –9C. Inna Vladimirskaya, 32, strips off on the banks of the Dnieper river, in Kiev, Ukraine, every Sunday morning, and takes a swim after jogging along the snowy banks of the river in the nip. (Photo by David Tesinsky/Caters News Agency)

Portuguese runner Adriele Silva gestures during the Great Wall Marathon at the Huangyaguan section of the Great Wall of China, in Jixian of Tianjin, China May 19, 2018. (Photo by Jason Lee/Reuters)

“A Hadaka Matsuri (“Naked Festival”) is a type of Japanese festival, or matsuri, in which participants wear a minimum amount of clothing; usually just a Japanese loincloth (called fundoshi), sometimes with a short happi coat, and rarely completely naked. Whatever the clothing, it is considered to be above vulgar, or everyday, undergarments, and on the level of holy Japanese shrine attire. Naked festivals are held in dozens of places throughout Japan every year, usually in the summer or winter. The most famous festival is held in Okayama, where the festival originated. Every year, over 9,000 men participate in this festival”. – Wikipedia

Photo: Japanese men wear loincloths as they splash about in freezing cold water during Saidaiji Naked Festival, at Saidaiji Temple on February 18, 2012 in Okayama, Japan. (Photo by Buddhika Weerasinghe/Getty Images)

Competitors take to the streets of the capital in fabulous fancy dress costumes during the Virgin London Marathon 2012 on April 22, 2012 in London, England. (Photo by Mirror.co.uk)

A woman leaves sauna during the sauna marathon in Otepaa, Estonia on February 2, 2019. Participants have to track down, locate and visit designated saunas in the Otepaa area as fast as possible during the event. The team that completed all of the saunas in the shortest time wins. (Photo by Ints Kalnins/Reuters)