A Polish Army tank takes part in the NATO Noble Jump exercise on a training range near Swietoszow Zagan, Poland, Thursday, June 18, 2015. (AP Photo/Alik Keplicz)

Green Bay Packers' Johnathan Calvin rides a bike to NFL football training camp on July 27, 2017, in Green Bay, Wis. (Photo by Morry Gash/AP Photo)

Heimana Reynolds of USA in action during a training session prior to the World Skate Park World Championships at the Parque Candido Portin​ari in Sao Paulo, Brazil, 11 September 2019. (Photo by Sebastião Moreira/EPA/EFE)

A couple shares a light moment in a Mass Transit Railway (MTR) subway train in Hong Kong, China on August 28, 2019. (Photo by Anushree Fadnavis/Reuters)

Two holidaymakers amuse themselves with a porter's trolley whilst waiting for their train at Euston Station, London, 5th August 1939. (Photo by A. J. O'Brien/Fox Photos/Getty Images)

A lenticular cloud is seen during sunrise from Gokmen Aerospace Training Center (GUHEM) in Bursa, Turkiye on January 19, 2023. (Photo by Halit Mirahmetoglu/Anadolu Agency via Getty Images)

Celera Barnes of the United States trains during a warm up session before the start of the World Athletics Indoor Championships at the Emirates Arena in Glasgow, Scotland, Thursday, February 29, 2024. (Photo by Bernat Armangue/AP Photo)

American paratroopers from the the 82nd Expeditionary Rescue Squadron take part in training for rescue operations in East Africa in the last decade of April 2024. (Photo by Senior Airman Olivia Gibson/US Air Force/CMA)