We examined two general measures of morbidity, musculoskeletal problems and respiratory symptoms, among participants of a 42 km race. We compared the morbidity experience of these participants to runners racing shorter distance events (5 km and 10 km) on the same day. Male marathon runners were almost twice as likely (and female marathon runners four times as likely) to report a lower extremity musculoskeletal problem in the month after the race as nonmarathon runners. Although adjusting for other factors did not change the crude odds ratio for either men or women, logistic regression results indicated that the strongest factor associated with lower extremity musculoskeletal problems in the month after the marathon was the report of a musculoskeletal problem in the year before the marathon. Neither male nor female marathon runners reported an excess of respiratory symptoms compared to those who ran shorter distances. However, a report of respiratory symptoms in the month before the race was statistically associated with respiratory symptoms in the month after the race. These results suggest that runners who have had lower extremity musculoskeletal problems in the year before, or those who have recently experienced respiratory symptoms, should use caution when preparing for and recovering from racing events.