The star health fad of the 2016 Olympics was definitely cupping, in which a trainer attaches a glass or plastic bell to an athlete's skin by heating the cup or using a suction device. The idea is that the suction from the cup pulls blood to the surface of the skin, breaking capillaries. According to Brian Resnick at Vox, practitioners believe that it helps in recovery and reduces pain. medicine practitioners believe it opens up qi channels.