A U.S. Marine leads training on a shooting range in France in an undated photo taken during the First World War. (Photo by Reuters/Courtesy Library of Congress)
A girl rides on a train as she takes part in the first edition of the No Pants Subway Ride in Bucharest, Romania, Sunday, January 11, 2015. The No Pants Subway Ride is an annual which was started in 2002 by Improv Everywhere in New York, the goal is for riders to get on the subway train dressed in normal winter clothes without pants and keep a straight face. (Photo by Vadim Ghirda/AP Photo)
In this picture taken on January 11, 2021, young gymnasts train at the Li Xiaoshuang Gymnastics School in Xiantao, Hubei province. This summer's delayed Tokyo Olympics, which are now due to start on July 23, 2021, will be the defining moment for Chinese gymnasts who have trained relentlessly since as young as age four in the pursuit of gold. (Photo by Nicolas Asfouri/AFP Photo)
Urszula Sidoruk, 19, from the paramilitary group SJS Strzelec (Shooters Association), trains her workout at a gym in Siedlce, eastern Poland March 18, 2014. Inspired by the war in Ukraine, growing numbers of Poles are joining volunteer paramilitary groups, where they receive basic army training and prepare to defend their homeland. (Photo by Kacper Pempel/Reuters)