Post-Exercise Cardiac Troponin Release is Related to Exercise Training History

Marathon running can increase circulating cardiac troponin above the diagnostic criteria for myocardial infarction. We determined whether prior-exercise experience (training history) might be related to the magnitude of immediate post-race troponin release following completion of the London Marathon in a group of non-elite runners. Using a prospective study design, 52 runners were recruited into either HIGH T-E (trained-experience) (n = 27) or LOW T-E (n = 25) groups. Cardiac troponin I (cTnI) release following race completion was compared between these 2 groups. To examine relationships between cTnI release and participant demographic and indices of prior training experience an additional 52 runners who did not meet the criteria for either the HIGH T-E or LOW T-E groups were also recruited. The combined data from all 104 runners was analysed using multivariate linear regression analysis. The results revealed a significant difference in post marathon circulating cTnI between LOW T-E runners (median: 0.11 mu g/L; interquartile range [IQR]: 0.030.18 mu g/L) and HIGH T-E runners (median: 0.03 mu g/L; IQR 0.02-0.057 mu g/L) (p < 0.05). Average miles run per week in the last 3 years, a marker of total training experience, encompassing training volume and duration, was negatively associated with post-marathon cTnI release (p < 0.001). In conclusion, exercise-induced cTnI release is strongly related to previous training experience.