Background: Regular aerobic exercise has beneficial effects on the cardiovascular system. Marathon running is an aerobic and extremely vigorous exercise. Arterial stiffness and wave reflections are independent predictors of cardiovascular risk. We investigated the acute effect of marathon race on aortic stiffness and wave reflections, as well as possible chronic alterations of these indexes in marathon runners.
Methods: We studied 49 marathon runners (age 38 +/- 9 years) and 46 recreationally active control subjects (age 37 +/- 5 years). To investigate the acute effect of marathon race, a subgroup of 20 runners was evaluated after the race as well. Aortic stiffness was evaluated with carotid-femoral pulse wave velocity (PWV) and wave reflections with augmentation index (AIx).
Results: Marathon runners had significantly higher systolic, diastolic, pulse (both aortic and brachial), and mean pressures compared to controls (P < 0.05 for all). Marathon runners had significantly higher PWV (6.89 m/s vs. 6.33 m/s, P < 0.01), whereas there was no difference in AIx and AIx corrected for heart rate (AIx@75) compared to controls (13.8% vs. 13.9%, P = 0.985 and 8.2% vs. 10.3%, P = 0.340, respectively). Marathon race caused a significant fall in both AIx (12.2% vs. -5.8%, P < 0.001) and AIx@75 (7.0% vs. 0.0%, P = 0.01), whereas PWV did not change significantly (6.66 m/s vs. 6.74 m/s, P = 0.690). Aortic and brachial systolic, diastolic, and mean pressures were also decreased (P < 0.05).
Conclusions: A significant fall in wave reflections was observed after marathon race, whereas aortic stiffness was not altered. Moreover, marathon runners have increased aortic stiffness and pressures, whereas wave reflections indexes do not differ compared to controls.