Brazilian natives of the Pareci tribe play head football with a hand-made ball for a demonstration, during the first day of the International Games of Indigenous Peoples, in Cuiaba, state of Mato Grosso, on November 10, 2013. 1500 natives from 49 Brazilian ethnic groups and from another 17 countries are gathering in Cuiaba until November 16 to compete in some 30 athletic disciplines, many of their own. (Photo by Christophe Simon/AFP Photo)

A female soccer player controls a ball during a training session at the Golab Trust Sport Complex in Kabul March 10, 2014. Despite decades of conflict in Afghanistan, and several recent militant attacks, the country's capital Kabul is home to a vibrant youth scene of musicians, artists, athletes and activists. Shopping malls and cafes stand in the city, which is nonetheless beset by infrastructure problems and instability. (Photo by Morteza Nikoubazl/Reuters)

Athletes of single bamboo drifting perform during the 9th National Traditional Games of Ethnic Minorities of the People's Republic of China on September 11, 2011 in Guiyang, China. (Photo by Feng Li/Getty Images)

Iranian athlete Maryam Toosi practises on the rooftop of her apartment building following the closure of sports facilities as part of measures aimed at containing the COVID-19 coronavirus, in Iran's capital Tehran on May 19, 2020. The coronavirus pandemic has forced the world's athletes to keep fit in confinement. The novel coronavirus has claimed the lives of nearly 7,200 people in Iran, making it the deadliest outbreak in the Middle East. The government ordered the closure of sports facilities in mid-March as part of measures aimed at containing the virus. (Photo by Atta Kenare/AFP Photo)

The beard of a skater, one out of some 1,100 athletes, is covered with ice and snow during the 200 km (124 miles) speed skating race in the Carinthian village of Techendorf January 30, 2015. Techendorf is hosting the Alternatieve Elfstedentocht Weissensee (Alternative Eleven City Races Weissensee) races, a traditional Dutch series of speed skating events for both professionals and amateurs with some 5,000 participants, until January 31, 2015. (Photo by Leonhard Foeger/Reuters)

An athlete dressed as a clown jumps into the Mediterranean sea as he takes part in the Copa Nadal in the Spanish port of Barcelona in Barcelona, Spain, Sunday, December 25, 2016. The Copa Nadal (Christmas Cup) is a traditional swimming competition that takes place in Barcelona every December 25th, where participants swim 200 meters in the open sea in the port of Barcelona. (Photo by Manu Fernandez/AP Photo)

Girls practice sit-ups during gymnastics lessons at the Shanghai Yangpu Youth Amateur Athletic School in Shanghai, China, on May 4, 2016. China's sports system has been enormously successful since the country returned to the Olympic fold in 1980, culminating with the host nation topping the medals' table at the 2008 Beijing Olympics. And yet, with the Rio de Janeiro Games less than three months away, the system is beginning to break down due to the shifting demographics of a more prosperous nation. (Photo by Aly Song/Reuters)

Anna Sloan and Vicki Adams of Britain sweep during a match against Olympic Athletes from Russia in Session 1 of the Women' s Round Robin curling competition at the 2018 Winter Olympic Games at Gangneung Curling Centre in Gangneung, South Korea on February 14, 2018. The British team won the match convincingly, 10-3. (Photo by Cathal McNaughton/Reuters)