REVEALED - Why some Olympic athletes have those little red marks on them

Michael Phelps had the red marks on his right shoulder last night

Watched much of the Olympics recently? You may have noticed that several athletes - particularly the American ones - have small red circle marks on their body.

The marks as the result of a process known as 'cupping', an ancient form of acupuncture popularised by celebrities such as Gwyneth Paltrow and Jennifer Aniston, where hot cups are placed on the skin to create a vacuum. The suction is said to improve blood flow, and that's what creates those little marks.