A participant runs through colored powder as she takes part in the Get Rainbowed run in Prague May 23, 2015. Get Rainbowed is a five-kilometre race with the aim of promoting a healthy lifestyle. (Photo by David W. Cerny/Reuters)

A participant sets off on a penny-farthing bicycle at the start of the The Tweed Run in central London, Britain, May 14, 2016. The Tweed Run, a very British public bicycle ride through London's streets, with a prerequisite that participants are dressed in their best tweed cycling attire. (Photo by Hannah McKay/Reuters)

Brides-to-be participate in the "Running of the Brides" race in a park in Bangkok November 28, 2015. A hundred husbands and wives-to-be wore their wedding dresses and running shoes and competed in an event for a combined prize worth 1 million Thai baht ($27,928), according to the organisers. (Photo by Athit Perawongmetha/Reuters)

A man takes pictures at the finish line during the Colour Run at Centennial Park in Sydney August 25, 2013. According to organizers, 15,000 runners registered to complete the 5km (3 miles) course in Centennial Park on Sunday, being covered in blue, pink, orange and yellow powder on their way to the finish line. (Photo by Daniel Munoz/Reuters)

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)

This picture taken on February 23, 2014 shows participants wearing dresses running half-naked in the annual 3.5 km Undie Run held in the Olympic Forest Park smog-covered Beijing. Some 200 participants took part in this event, many of them with gas masks, as dangerous smog blighted swathes of northern China in recent days. (Photo by AFP Photo/STR)

Participants take part in the Color Run near the Eiffel Tower in Paris April 19, 2015. The Color Run is a five-kilometre race, held in cities across the U.S. and also worldwide, with the aim of promoting healthy living and to benefit a charity that organizers choose in each of the cities that the run visits. Participants are doused from head to toe in different colors at each kilometre. (Photo by Benoit Tessier/Reuters)

Competitors take part in the Christmas Really Wild Mud Run on a 4.6 miles course across undulating farm land at Celtic Camping, St David's, Pembrokeshire, Wales, December 12, 2015. (Photo by Rebecca Naden/Reuters)