Athlete's hepatitis is a rare form of ischemic hepatitis caused by hypoxic liver injury during extreme physical exertion. We present the case of a 25-year-old healthy male who developed severe transaminitis after completing a half-marathon. He presented with syncope, hypotension, and hyperthermia, followed by markedly elevated liver enzymes. An extensive evaluation ruled out viral, toxic, and structural causes of liver injury. Conservative management led to full recovery, with liver enzymes normalizing within one week. This case highlights the liver's susceptibility to ischemic injury during intense exercise due to blood flow redistribution to active muscles. Although rare, athlete's hepatitis should be considered in the differential diagnosis of acute liver injury in athletes. Early recognition and supportive care are essential for favorable outcomes.