An aerial view shows the the Mountain Bike course at the X-Park at Deodoro Olympic Park ahead of the 2016 Rio Olympics in Rio de Janeiro, Brazil, July 16, 2016. (Photo by Ricardo Moraes/Reuters)

A man covered with mineral-rich mud smiles on a bank of lake Tus in Khakassia region, southwest of the Siberian city of Krasnoyarsk, Russia, July 16, 2016. (Photo by Ilya Naymushin/Reuters)

Libyan forces allied with the U.N.-backed government fire weapons during a battle with IS fighters in Sirte, Libya, July 21, 2016. (Photo by Goran Tomasevic/Reuters)

Commuters use a plastic sheet to take shelter from rain as they ride through a waterlogged road in Ahmedabad, India, July 27, 2016. (Photo by Amit Dave/Reuters)

A fighter of Libyan forces allied with the U.N.-backed government runs for cover during a battle with Islamic State fighters in Sirte, Libya, July 31, 2016. (Photo by Goran Tomasevic/Reuters)

A Mongolian wrestler adjusts her hair before a match during the 2016 World Sumo Championship on July 30, 2016 in Ulaanbaatar, Mongolia. (Photo by Taylor Weidman/Getty Images)

Indian policewomen perform a stunt on their motorbikes during the full-dress rehearsal ahead of India's Independence Day celebrations in Srinagar, August 13, 2016. (Photo by Danish Ismail/Reuters)

Two race pigs jump over an obstacle during a rural festivity in reference to Maria Ascension in San Bernardino, Switzerland on Monday, August 15 2016. (Photo by Samuel Golay/Keystone/TI-Press via AP Photo)