What is cupping and why are so many Olympians trying it?

Aug 8, 2016 at 1:20 p.m. ET
Image: Julian Finney/Getty Images Sport

Crop circles? Paintball bruises? Overly aggressive hickeys? As Olympic swimmers racked up medals and destroyed world records last night, much of the world was more fascinated by the purple circles on their backs than the gold circles on their chests. So what are those things and why would anyone do that to themselves?

Swim king Michael Phelps, along with teammate Natalie Coughlin and gymnast Alex Naddour looked like they'd been attacked by an extra-large bingo marker this weekend as they competed in the 2016 Rio Olympics, sporting circular red and purple bruises on their arms, shoulders and backs. But they're not the result of chicken pox on steroids, rather they're the marks left from cupping, an ancient healing art with roots in traditional Chinese, Egyptian and Middle Eastern medicine.

Cupping involves placing 1- to 3-inch cups over parts of the body that are sore or injured and then using either heat or mechanical suction to briefly suck the skin and muscle up inside the cup. When the cup is released it leaves those funny-looking circles on the skin, courtesy of broken blood vessels and bruising, which can last up to two weeks after the treatment.

More: What is cupping?

But while it may sound (and look) agonizing, it's actually quite relaxing says certified and licensed acupuncturist Lisa Alvarez, co-founder of Healing Foundations, an Oriental medicine practice. "In brings a sense of relaxation and overall well-being," she explains, adding that many of her clients actually fall asleep on the table.

"Think of it like a reverse massage," she explains. "Instead of pushing the muscles into the body to get them to relax, suction is used to gently pull the muscle tissue upward to help it release."

And it's perfect for athletes, she says, as the practice increases circulation to the muscles. According to Alvarez, cupping can help improve performance and speed recovery after a tough workout. Plus, it can provide pain relief from injury or sore muscles.

Alex Naddour, for one, says it definitely works. "Cupping provides relief from the soreness and pounding that come from gymnastics. That's been the secret that I have had through this year that keeps me healthy," he told USA Today. "It's been better than any money I've spent on anything else and it has saved me from a lot of pain."

Not everyone is such a fan, however. There isn't much scientific research into cupping therapy and what little there is relies primarily on anecdotal evidence or is of poor methodological quality, as shown in this 2012 meta-analysis.

"There’s no science behind it whatsoever," David Colquhoun, professor of pharmacology at University College London told the Independent. "It’s not for scientists to show how it can’t work, but it’s [practitioners’] business to prove that it does work, which they haven’t done. But it’s desperately implausible, how the hell should sucking up a bit of skin in a cup do anything to your athletic performance? If it’s done enough to cause bruising, it is [breaking blood vessels], and that’s not going to help anybody is it?"

Still, there aren't any lasting negative side effects to cupping so it seems like one of those things that can't hurt to try and if it helps you feel better then who cares if it's legit or the placebo effect? At any rate, who are we to argue with the best athletes in the world?

More: U.S. Olympics men's swim team: Get to know the 24 men in the Speedos