Racial Differences in Arterial Stiffness During Recovery Following Repeated Bouts of Maximal Anaerobic Cycling Exercise in Young Women

African Americans (AA) experience a differential cardiovascular response during recovery from aerobic exercise compared to Caucasian Americans (CA). There is also evidence that local and systemic vasculature responds differently to aerobic exercise stimulus. No study has examined racial differences in arterial stiffness following maximal anaerobic exercise in AA and CA women. Purpose: To compare local and systemic arterial stiffness during recovery from repeated bouts of maximal anaerobic exercise in young, healthy AA and CA women. Methods: Twenty (AA=8; CA=12) young, healthy women without hypertension completed two bouts of maximal anerobic exercise on a cycle ergometer with 30 minutes of recovery between bouts. Brachial blood pressure and hemodynamic measurements were taken at rest and 5-, 15- and 30- minutes following each bout of exercise. Arterial compliance (AC) was assessed using ultrasound to evaluate local carotid arterial stiffness. Systemic arterial stiffness measured by augmentation index (AIx@75) and segmental arterial stiffness measured by central Pulse Wave Velocity (cPWV) were assessed with SphygmoCor. Two-way repeated measures ANOVA was used to test for possible race (two levels) and time (7 levels) differences between AA and CA. Results: There was a significant race by time interaction for AC and MAP (P ≤ 0.5). There was a main effect of time for AIx@75, which increased immediately following exercise and returned to baseline 30 minutes following exercise, regardless of race (P ≤ 0.05). There was no change in cPWV in response to exercise in either group. Conclusion: Local carotid arterial compliance and brachial blood pressure respond differently in AA women compared to CA women following repeated bouts of maximal anaerobic exercise, despite similar systemic or segmental arterial stiffness. Racial differences in arterial distensibility between AA and CA women in response to maximal anaerobic exercise may be limited to localized changes in the predominantly elastic carotid artery. In addition, while no racial differences were observed in systemic arterial stiffness, repeated maximal anaerobic exercise induces peripheral arterial stiffness but does not induce changes in central arterial stiffness in all participants