The Bottom Line: Troponin increases were relatively common among marathon finishers and can reach levels typically diagnostic for acute myocardial infarction. Less marathon experience and younger age appeared to be associated with troponin increases, whereas race duration and the presence of traditional cardiovascular risk factors were not. Further work is needed to determine the clinical significance of these findings.
Summary: Of 766 runners enrolled, 482 had blood analyzed at the finish line. In all, 34% were women, 20% were younger than 30 years, and 92% had run at least 1 previous marathon. Most runners (68%) had some degree of postrace troponin increase, and 55 (11%) had significant increases. Running inexperience (5 previous marathons) and young age (30 years) were associated with elevated troponins. These correlates were robust throughout a wide range of troponin thresholds considered. Health factors, family history, training, race performance, and symptoms were not associated with increases.