Short-term effects of marathon running: no evidence of cardiac dysfunction

Purpose: The purpose of this study was to analyze the short-term effects of a marathon race (Madrid Marathon) on both markers of cardiac damage and ec hocardiographic parameters in a group of 22 runners (17 male and 5 female: 34 +/- 5 yr; (V) over dotO(2max): 55.7 +/- 9.1 mL.kg(-1).min(-1)) with a wi de range of fitness levels. Methods: Venous blood samples were collected fr om each subject 48 h before the race, at race finish, and 6, 24, and 48 h p ostexercise for the determination of myoglobin, total creatine kinase catal ytic activity (total CK), mass concentration of creatine kinase isoenzyme M B (CK-MB mass), and cardiac isoforms of troponin T and I (TnT-c and TnI-c, respectively). in addition, echocardiographic parameters (M-mode two-dimens ional and Doppler analysis) indicative of both left ventricular (LV) systol ic and diastolic function were obtained three times from each runner: 2-5 d before the race, at race finish, and 24-36 h after exercise. Results: Exce pt in one subject, levels of TnT-c and TnI-c were within normal limits (<0. 1 ng.mL(-1)) in ail the samples collected before or after the race. Overall LV systolic function was not altered by marathon running. Finally, LV dias tolic function was transiently altered after the race since the ratio betwe en peak early and late transmitral filling velocities (E/A) was significant ly reduced at race finish (P < 0.01) and returned to resting levels after 2 4-36 h. Conclusions: Our findings suggest that marathon running does not ad versely affect the hearts of healthy individuals independently from their t raining status.