extreme endurance physical exercise mostly seen Repetitive Motion Injuries extreme endurance physical exercise WebMD extreme endurance physical exercise extreme endurance physical exercise extreme endurance physical exercise WebMD extreme endurance physical exercise WebMD extreme endurance physical exercise Repetitive Motion injuries extreme endurance physical exercise extreme endurance physical exercise Repetitive motions most common repetitive motion injuries extreme endurance physical exercise repetitive motion injuries extreme endurance physical exercise extreme endurance physical exercise extreme endurance physical exercise extreme endurance physical exercise Repetitive motion injuries extreme endurance physical exercise extreme endurance physical exercise potentially career-damaging injury extreme endurance physical exercise extreme endurance physical exercise extreme endurance physical exercise more common extreme endurance physical exercise repetitive motions extreme endurance physical exercise extreme endurance physical exercise extreme endurance physical exercise extreme endurance physical exercise extreme endurance physical exercise WebMD extreme endurance physical exercise extreme endurance physical exercise extreme endurance physical exercise