The unexpected reason Olympic athletes bite their medals

Al Bello/Getty Images

US swimmer Ryan Lochte bites one of his Olympic medals in 2012.

Olympic athletes have a habit of biting their medals on the podium - but nobody really knows why. In fact, it's such an enduring mystery that even Olympic historians don't understand it.

"We have no idea why they do it,"Anthony Bijkerk, secretary-general of the International Society of Olympic Historians told INSIDER in an email. "As far as I know, it is an old habit."

But NBC recently posed the question to two Olympians, and the athletes finally revealed the secret behind all the medal-biting.

The photographers tell them to do it.

In a video shared by NBC last week, former Olympic swimmer Natalie Coughlin and former Olympic hurdler Dawn Harper-Nelson said that, after winning their medals, they were faced by a mob of press photographers who demanded they bite their newly acquired hardware.

"They're screaming, 'Look at me!' You just have everyone yelling demands of 'Smile!' and 'Bite your medal!'" Harper-Nelson explained.

"They wear you down and they make you bite it," Couhglin agreed.

The video also debunks the theory that biting gold medals is a way to test their authenticity. (Gold is so soft that a bite will leave marks, meaning it's easy to tell when it's real and when it's not.) But Olympic gold medals haven't been made of solid gold since 1912, CNN reports.

Funnily enough, today's gold medals are made of 99% silver.