Watching US swimmer Michael Phelps in the Rio 2016 pools, is it possible to see some dark red circle on his body.

What is the cause of these marks?

In the picture below you can see those marks on the right shoulder:

Phelps red cirlce

1 Answer 1


The circles are actually the result of a purported recovery practice called cupping. Practitioners claim that it aids in blood flow and recovery to various body parts. Considered a form of alternative medicine, there’s no study evidence for its efficacy. It seems to be the latest fad for high level athletes.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.