RIO DE JANEIRO — Olympics trivia: What has 19 gold medals and a bunch of purple circles?
If you watched a certain swimmer’s Rio Games debut on Sunday night, when he propelled the United States 4×100-meter relay team to a gold medal, you know the answer: Michael Phelps.
While it may look like Phelps and several other Olympians with those skin marks have been in a bar fight, the telltale dots actually are signs of “cupping,” an ancient Chinese healing practice that is experiencing an Olympic moment.
“Because this particular recovery modality shows blemishes on his skin, he walks around and looks like a Dalmatian or a really bad tattoo sleeve,” said Keenan Robinson, Phelps’s personal trainer. “It’s just another recovery modality. There’s nothing really particularly special about it.”
Practitioners of the healing technique — or sometimes the athletes themselves — place specialized cups on the skin. Then they use either heat or an air pump to create suction between the cup and the skin, pulling the skin slightly up and away from the underlying muscles.
The suction typically lasts for only a few minutes, but it’s enough time to cause the capillaries just beneath the surface to rupture, creating the circular, eye-catching bruises that have been so visible on Phelps as well as members of the United States men’s gymnastics team. If the bruising effect looks oddly familiar, it’s because it’s the same thing that happens when someone sucks on your neck and leaves a hickey.
“I’ve done it before meets, pretty much every meet I go to,” Phelps said on Monday. “So I asked for a little cupping yesterday because I was sore and the trainer hit me pretty hard and left a couple of bruises.”
Physiologically, cupping is thought to draw blood to the affected area, reducing soreness and speeding healing of overworked muscles. Athletes who use it swear by it, saying it keeps them injury free and speeds recovery. Phelps, whose shoulders were dotted with the purple marks as he powered the relay team, featured a cupping treatment in a recent video for a sponsor. He also posted an Instagram photo showing himself stretched on a table as his Olympic swimming teammate Allison Schmitt placed several pressurized cups along the back of his thighs. “Thanks for my cupping today!” he wrote.
“There is a psychological component where Michael has been doing this to feel good for a long time, about two years,” Mr. Robinson said. “Anything you can do to get the body to feel good — you have to use an educational assessment on it. You have to make sure that what you’re doing is causing a physiological intent to recover.
“I’m not just going to throw a stick of butter on him,” Robinson said, adding, “I’m going to make sure I have an educated approach to it.”
While there’s no question that many athletes, coaches and trainers believe in the treatment, there’s not much science to determine whether cupping offers a real physiological benefit or whether the athletes simply are enjoying a placebo effect.
One 2012 study of 61 people with chronic neck pain compared cupping to a technique called progressive muscle relaxation, or P.M.R., during which a patient deliberately tenses his muscles and then focuses on relaxing them. Half the patients used cupping while the other half used P.M.R. Both patient groups reported similar reductions in pain after 12 weeks of treatment. Notably, the patients who had used cupping scored higher on measurements of well-being and felt less pain when pressure was applied to the area. Even so, the researchers noted that more study is needed to determine the potential benefits of cupping.
Another experiment involving 40 patients who suffered from knee arthritis found that people who underwent cupping reported less pain after four months compared to arthritis sufferers in a control group who were not treated. But the cupped group knew they were being treated — it’s not easy to blind people about whether a suction cup is being attached to their leg or not — and so the benefits might have been due primarily to a placebo effect.