From the gymnasium to the pool, a roster of Olympians are sporting the ancient Chinese practice's characteristic large red spots

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When Michael Phelps joined the line-up for Sunday’s 4x100m men’s freestyle relay, there was one thing that everyone couldn’t help but notice - a number of large red circles on the athlete’s shoulders. The reason? Cupping. And he isn’t the only one going dotty for the trend.

What exactly is cupping? An ancient Chinese therapy, it’s believed to relieve muscle soreness, pain and stiffness and involves the use of special cups placed on different parts of the body to pull blood up to the skin’s surface to improve circulation and loosen joints. The trend has also garnered quite the celebrity following too, with Jennifer Aniston , Gwyneth Paltrow and Justin Bieber reportedly regarded as fans too. However, it seems the trend has made the leap from red carpet to Rio with a roster of Olympic athletes all having been spotted sporting its characteristic red circles on their bodies.

Fans include USA swimmer Natalie Coughlin and American gymnast Alexander Naddour. “That’s been the secret that I have had through this year that keeps me healthy,” says Naddour,  reports USA Today . “It’s been better than any money I’ve spent on anything else.” Traditionally, the cups are heated up by lighting a flammable liquid, with the decrease in temperature creating its distinctive suction action however, at-home kits are also available using a pump instead. A DIY approach has also been said to have been encouraged from team captain Chris Brooks: “You’re like, ‘OK, I’m sore here,’” he said. “Throw a cup on, and your roommate will help you or you can do it yourself.”

With Phelps already adding a 19th gold medal to his illustrious list of Olympic achievements, it looks like we won’t be seeing athletes changing their spots any time soon.

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