Purple circles on Michael Phelps’ body are a result of an ancient healing practice

If you’ve watched swimming legend Michael Phelps at the Rio Olympics, you’ve likely noticed something odd. Those purple circles that are on his body in random spots, right?

That is a result of a technique called “cupping,” which dates back centuries. My friend Nichelle Nichols is a massage therapist and she’s been using cupping on patients for years. A glass cup is heated and placed on the body for up to several minutes, and it creates a suction on the body (yes, think hickies).

Nichols said the procedure helps release toxins in the body, calms the nervous system and helps inflamed connective tissue. It has been used as a healing practice, and she uses it on patients with muscle spasms. You can read much more about it here.

Cupping was part of an Under Armour commercial featuring Phelps and you can see it here (it’s at the 40 second mark of the video):

Last year, Phelps shared a photo on his Instagram account of the procedure:

It’s not just Phelps and his fellow swimmers who are doing it, either. This is a photo of gymnast Alex Naddour:

This story was originally published August 8, 2016 at 1:43 PM.