Last year, it wasn't just Michael Phelps' big win in the Rio Olympics that had people talking about the U.S. swimming star. It was also the dark purple circles on his shoulders. Phelps, who won the 19th Olympic gold medal of his career in Rio and helped the U.S. men's team to victory in the 4x100 meters freestyle relay, is one of a number of Olympic athletes practicing "cupping," an ancient Chinese healing practice.

During the therapy cups are placed on the section of the body in need of repair to create suction. The method is said to draw out any toxins, mobilize blood flow, soothe sore muscles and even help cure insomnia.

Actresses Gwyneth Paltrow, Jennifer Aniston and pop star Justin Bieber have also been photographed with the distinctive large circles on their backs and chest.

Watch this video demonstration by a Chinese Foot Reflexology and Cupping expert Deng Rong to know more about the soothing and calming technique.

(With inputs from Reuters)

Video Editor: Purnendu Pritam