When Italian swimmer Nicolo Martinenghi won the 100m breaststroke on Sunday, he showcased some very eye-catching marks on his body. He is not the first athlete to show off these spots that almost look like bruises. Swimmer Michael Phelps also had them during various competitions, just like footballer Karim Benzema and boxer Floyd Mayweather. It is not only common among athletes, celebrities like Justin Bieber, Jennifer Aniston, and Gwyneth Paltrow have also shown the same marks. But what exactly are they? It’s the result of cupping therapy, an ancient Chinese technique often used to relieve pa…