A dancer performs during the Gymnastics Rio Gala on Day 12 of the 2016 Rio Olympic Games on August 17, 2016 in Rio de Janeiro, Brazil. (Photo by Clive Brunskill/Getty Images)

A large sand sculpture is seen at the site of Yokohama Sand Art Exhibition – Culture City of East Asia 2014 on July 16, 2014 in Yokohama, Japan. Producer and sand sculptor Katsuhiko Chaen invited artists from around the world including South Korea and China, to recreate the World Heritage and historical buildings in China, Japan and South Korea. The exhibition will be open from July 19 to November 3, 2014. (Photo by Chris McGrath/Getty Images)

American model Isabella Khair Hadid is seen on March 13, 2018 in Los Angeles, California. (Photo by The Mega Agency)

Skeleton involves a person riding a small sled down a frozen track while lying face down. The sport is a more intense form of luge because skeleton competitors leap onto the sled and slide downhill head first. Skeleton athletes can reach up to 80 mph on straightaways, causing forces up to 5g, so the helmet is a critical component for attitude as well as safety.

Tao Xiangli gets out of his homemade submarine after operating it in a lake on the outskirts of Beijing September 3, 2009. Amateur inventor Tao, 34, made a fully functional submarine, which has a periscope, depth control tanks, electric motors, manometer, and two propellers, from old oil barrels and tools which he bought at a second-hand market. He took 2 years to invent and test the submarine which costs 30,000 yuan ($4,385). (Photo by Christina Hu/Reuters)

A health worker applies a dose of the AstraZeneca vaccine during the first day of a three-day COVID-19 vaccination campaign for people over age 35 in the Complexo da Maré favela of Rio de Janeiro, Brazil, Brazil, Thursday, July 29, 2021. Some recipients will be monitored to study the rate of protection the vaccines provide and the extent to which virus variants are circulating. (Photo by Bruna Prado/AP Photo)

A billboard depicting a soldier, with a slogan reading “Contract service. A real man's job”, in St. Petersburg, Russia, 02 June 2023. On 24 February 2022, Russian troops entered Ukrainian territory in what the Russian president declared a “Special Military Operation”, starting an armed conflict. (Photo by Anatoly Maltsev/EPA)

Participants bathe in ice-cold water during a ceremony at Teppozu Inari Shrine in Tokyo, Japan, 12 January 2025. 80 men and women took part in the ice water endurance ceremony to purify their souls and pray for good health in the new year. (Photo by Franck Robichon/EPA/EFE)