A participant of the Wild Sau Dirt Run 2015 passes a mud barrier in Obertriesting, Lower Austria, Austria, Saturday, April 4, 2015. The Wild Sau Dirt Run is a cross country and steeplechase race for men and women over the distances of 5, 10 and 20 kilometers (3.1, 6.2 and 12.4 miles). (Photo by Ronald Zak/AP Photo)

Some women doing yoga pose on the hammocks during the Anti-Gravity yoga class at Svarga e-Motion Sanctuary at Dharmawangsa Square, Jakarta, Saturday, April 18, 2015. Anti-Gravity Yoga or “aerial yoga”, is a new type of yoga, originating in New York but now being practised in several countries, which combines the traditional yoga poses, pilates and dance with the use of a hammock. (Photo by Jurnasyanto Sukarno/JG Photo)

Peter Ver Ploeg carries Virginia Petrovek through the mud pit during the North American Wife Carrying Championship, Saturday, October 8, 2016, at the Sunday River Ski Resort in Newry, Maine. (Photo by Robert F. Bukaty/AP Photo)

Members of La Legion, an elite unit of the Spanish Army, including a goat they use as a pet wait for the start of a military parade as they celebrate a holiday known as “Dia de la Hispanidad” or Hispanic Day in Madrid, Wednesday, October 12, 2016. (Photo by Daniel Ochoa de Olza/AP Photo)

Ave, 4 years-old, of the United States, paints on her father's hand during the International Tattoo Convention Bucharest 2016 in Bucharest, Romania, Sunday, October 16, 2016. Prominent tattoo artists from across the world displayed their skills in the Romanian capital over the weekend. (Photo by Vadim Ghirda/AP Photo)

People wearing costumes pose for a photograph as they participate in the annual “Zombie Walk” in Bordeaux, France on October 22, 2016. Several hundred people wearing costumes and makeup took part in the walk which was authorized despite the state of emergency. (Photo by Georges Gobet/AFP Photo)

Iranian Kurdish female members of the Freedom Party of Kurdistan (PAK) hold a position on November 6, 2016 in an area near the town of Bashiqa, some 25 kilometres north east of Mosul, during an operation against Islamic State (IS) group jihadists to retake the main hub city. (Photo by Safin Hamed/AFP Photo)

A Belarussian tourist crosses the river as he takes part in “Search and rescue operations – 2016”, a three-day competition, near the village of Priselki, Belarus, November 25, 2016. Photo taken November 25, 2016. (Photo by Vasily Fedosenko/Reuters)