@smilebebe619

Short-distance swimming is unquestionably an anaerobic sport. Besides technique, the ability to utilize oxygen effectively determines how fast one can swim. What carries oxygen? Hemoglobin. Thus, a higher level of hemoglobin, which carries more oxygen, can give a competitor a physical edge—this is an open secret in sports. Consequently, drugs that increase hemoglobin levels, such as erythropoietin and peginesatide, are banned as blood doping agents. After being utilized in large amounts in a short time, high levels of hemoglobin are reduced to a high concentration of reduced hemoglobin, resulting in methemoglobinemia. In clinical medicine, what color are the skin and visible mucous membranes associated with methemoglobinemia? The answer is purple. Therefore, please investigate the Americans.”

简言之：服用了增加血红蛋白的药物，增加携氧量，血红蛋白是红色的用完后，变成高铁血红蛋白。是紫色的，解释了为啥变脸，据此要求调查美国队。

这个感觉靠谱点！