U.S. Olympic Star Retires After Shocking Cardiac Arrest

David Ramos / Getty Images U.S. Olympic track athlete Jenny Simpson has revealed she will never run again after surviving a cardiac arrest during a training session in June. Simpson, 39, collapsed while running in North Carolina, requiring CPR and an automated external defibrillator before being rushed to the hospital. Doctors later diagnosed her with arrhythmogenic right ventricular…