At first glance, it looks like Michael Phelps is competing in Rio for the red, white and bruised. Before America’s most decorated swimmer jumped in the water en route to his 19th Olympic gold medal, it was impossible to overlook the circular marks all over his back and shoulders and wonder if he was hit with a barrage of tennis balls.
The bruises, it turns out, are the result of the ancient Chinese medicine practice known as “cupping.” Using round thick glasses placed directly onto the skin, cupping is supposed to relieve pain by improving blood flow from the suction.
Phelps has been using the treatment for some time. And, if his Under Armour commercial is on any guide, it’s part of his regular training regiment.
It’s not only athletes sporting the circular bruises, either. Celebrities such as Jennifer Anniston and Gwenyth Paltrow have been spotted around town with the distinct marks.
So does it actually work? There’s not a ton of evidence to support cupping. A 2012 study that looked at 135 randomized controlled trials of cupping therapy—dating to 1992—found they were “generally of low methodological quality.” And while a study published earlier this year in the Journal of Bodywork and Movement Therapies found initial scientific evidence that dry cupping is able to reduce musculoskeletal pain, one of the studies co-author’s told the New York Times, “a placebo effect is present in all treatments, and I am sure that it is substantial in the case of cupping as well. A patient can feel the treatment and has marks after it, and this can contribute to a placebo effect.”
But their 2016 study also found few side effects from cupping if performed properly—that is, if the recipient overlooks the bruising, skin discolouration, and generally looking like a reddish-purple human Dalmatian for days (even weeks) afterward. Another gold medal around Phelps’s neck is a pretty good way to divert the eyes.