Cupping involves having hot suction cups applied to the skin for several minutes, leaving what appears to be a circular love bite on the surface, which can take over two weeks to fade.
The technique has been used for millennia, but it shot to prominence in 2004, when US actor Gwyneth Paltrow attended a film premiere with circular marks peppering her skin.
Cupping is claimed by its practitioners to treat an array of ailments, including muscular pain, joint pain, skin problems including eczema and acne, respiratory disorders, including the common cold, pneumonia and bronchitis, and has also been used as an alternative treatment for cancer.
What does athlete say?
The athletes are among the latest adherents to the traditional Chinese medicine treatment known as “cupping”.
But the Rio Olympics provides us with growing evidence that athletes are turning to the alternative medicine in an attempt to boost their performance.
According to Mr Naddour he has found the treatment “provides relief from the soreness and pounding that come from gymnastics”.
He told USA Today: “That’s been the secret that I have had through this year that keeps me healthy. It’s been better than any money I’ve spent on anything else.”
“It has saved me from a lot of pain.”