Soldiers of China's People's Liberation Army (PLA) jump as part of their winter training in temperature of negative 26 degrees Celsius at China's border with Russia in Heihe, Heilongjiang province, December 14, 2015. (Photo by Reuters/Stringer)

Students training to be flight attendants hold books on their heads, chopsticks in their mouths, and papers in between their knees, as they take part in a standing posture practice at a vocational school in Shijiazhuang, Hebei province, China May 4, 2017. (Photo by Reuters/Stringer)

Iranian women perform as they train Far East Fighting Arts to be able to defend themselves, at the Jughin castle which is located 40 km's far from Tehran, Iran on June 5, 2017. (Photo by Fatemeh Bahrami/Anadolu Agency/Getty Images)

People cool off in a fountain outside the Southbank Centre on June 30, 2015 in London, England. The UK is currently experiencing a heatwave, with temperatures of 35 degree celsius forecast tomorrow in some parts of the country. The extreme heat has already seen train cancellations and a health warning has been issued. (Photo by Rob Stothard/Getty Images)

Police officers introduce a litter of golden retriever puppies to be trained as police dogs during a ceremony at the National Police Academy in La Paz, Bolivia, Monday, August 16, 2021, the date of the feast day for Saint Roch, considered the patron saint of dogs, among other things. (Photo by Juan Karita/AP Photo)

Vapour bounced off the wings of the Lockheed Martin F-35 Lightning II as it sped over the Welsh mountains at a swift 575mph on February 10, 2022. The jet was taking part in a low-level training exercise through the Mach Loop – a series of valleys in North Wales. (Photo by Thomas Winstone/News Images)

A young fan watches as Green Bay Packers running back AJ Dillon (28) tries his best to ride her bicycle to training camp on Monday, August 1, 2022, at Ray Nitschke Field in Green Bay, Wis. (Photo by Dan Powers/USA TODAY Sports)

Professional dancer Sandy Lewis, from Louisiana, performs with his dance partner Marti Gasol, as they train in the street due to restrictions to do it indoor, in Barcelona on Wednesday, November 11, 2020 as Spain continue with new measures against the COVID-19. (Photo by Emilio Morenatti/AP Photo)