Eight-year-old Niu Dongfang trains at the No. 2 Beijing Shuangqiao School January 13, 2005 in Beijing, China. Most of students in the gymnastics school have to study more than five years from as young as age six before they become athletes. (Photo by Guang Niu/Getty Images)

People board a train at the West Railway Station on January 7, 2012 in Beijing, China. China's railways are bracing themselves as millions of migrant labourers are set to leave cities for their native villages to celebrate the Chinese New Year. (Photo by Lintao Zhang/Getty Images)

Unloading a Cartopper from a UPRR work train at Port Barre Louisiana. Kinda scary to watch, but it worked like a charm.

Sergeant Andrew Garrett watches K-Dog, a bottlenose dolphin attached to Commander Task Unit 55.4.3, leap out of the water while training near the USS Gunston Hall March 18, 2003 in the Persian Gulf. (Photo by U.S. Navy/Getty Images)

Indian wrestlers Rashid Anwar (left) and Ajaib Singh in a training bout at Lane's Club in Baker Street London before the Empire Games, 19th July 1934. (Photo by Keystone/Hulton Archive/Getty Images)

Macaque monkeys crowd together in their cage at a monkey farm on February 3, 2016 in Xinye county, Henan province, China. The area boasts a centuries-long and lucrative history of raising and training monkeys for performance. In Xinye, villagers are seeing an increase in business with the lunar calendar's “Year of the Monkey”. Farmers say most of the monkeys are bred and raised for domestic zoos, circuses, and performing groups, but add that some are also sold for medical research in China and the United States. Despite the popularity of the tradition, critics contend the training methods and conditions constitute animal cruelty. (Photo by Kevin Frayer/Getty Images)

A woman poses as she has her picture taken amid 1600 panda bear sculptures in Berlin August 5, 2013. Marking the 50th anniversary of its existence, on Monday the German branch of the World Wide Fund for Nature (WWF) environmental conservation organisation placed 1600 panda bear sculptures on front of Berlin's main train station to draw attention to the plight of the endangered species that serves as the NGO's mascot. There are currently 1600 panda bears alive in the wild, the organisation said in a press release. (Photo by Thomas Peter/Reuters)

A Palestinian youth practices his Parkour skills over the ruins of houses, which witnesses said were destroyed during a seven-week Israeli offensive, in the Shejaia neighborhood east of Gaza City October 1, 2014. Some Palestinian youths aged between 13 and 17 years old, train in the devastated area as a personal initiative to develop their skills. Parkour is a physical discipline of movement focused on overcoming obstacles. (Photo by Mohammed Salem/Reuters)