You may have noticed several members of the U.S. Olympic team with red circles on their shoulder or arms.

The red circles are the result of an ancient Asian therapy called cupping. Cupping therapy involves placing cups on the skin to create suction, which then releases the toxins deep in the muscles. The suction leaves behind some intense purplish red circles.

The dots were visible Sunday when swimmer Michael Phelps helped lead the U.S. men's 4x100 freestyle relay team to a gold medal. Several members of the men's gymnastics team also use cupping. Athletes say it helps the muscles recover.

Acupuncturist Sarah Swanberg, of Fairfield Family Acupuncture in Stamford, says putting the suction cups on targeted areas increases blood flow and oxygen to that spot, which can reduce pain and inflammation. She says cupping is a great alternative to pain medication.

Swanberg also says it doesn't hurt and the large red circles typically fade in about a week.