Why do Olympic medalists bite their medals?

It has deeply impressed us that almost every medalist will bite down on his/her medal. It seems to be a standard pose for photos – a more common pose than just kissing the medal. But why do the Olympians feign chomping on their medals, anyway?

One obvious fact is that it's a pose photographers really like to capture. "It's become an obsession with the photographers," David Wallechinsky, the president of the International Society of Olympic Historians, told the CNN. "I think they look at it as an iconic shot, as something that you can probably sell. I don't think it's something the athletes would probably do on their own."

Some say that the practice is related to money counterfeiting. Money handlers would bite down on coins to test the purity, as gold is a relatively soft metal. When Olympians bite their medals, it harkens back to the notion that they're testing the "purity" of the gold, even though today they all realize that their medals are not solid gold. This year, each Olympic gold medal only contains 1.34 percent gold, and the rest is sterling silver. The proportion makes the 2016 Rio medals "the most sustainable ever made."

However, traditions die hard. This tradition should pay tribute to Matt Biondi, who won a gold medallion with his team in the 4×100-meter freestyle relay at the 1984 Los Angeles Olympics. Matt was believed to be the first Olympian to bite the gold medal, and the practice has been imitated by the subsequent Olympic winners since then. Without the trend, we would never have known about Ryan Lochte's diamond grill. The American swimmer won a gold medal in the men's 400 Individual Medley at the FINA Swimming World Championships in Rome in 2009. Gnawing on his gold prize while posing for photos, the winner made his diamond grill known to the world.

It's not just an Olympic phenomenon, though. Spanish tennis player Rafael Nadal famously gnaws his trophies when he wins.