Racial Differences In Cardiovascular Responses Following Acute Bouts Of Anaerobic Exercise

Abstract

Despite the growing popularity of high-intensity anaerobic exercise, few studies have examined the acute effects of this form of exercise on cardiovascular hemodynamics, or potential racial differences in these responses. In addition, post exercise hypotension may be absent in African Americans (AA) following aerobic exercise, consistent with their higher risk for hypertension. It is unknown whether AA and Caucasian Americans (CA) would exhibit different blood pressures following acute bouts of anaerobic exercise. PURPOSE: To assess hemodynamic changes in healthy, young AA and CA women following repeated bouts (two) of maximal anaerobic exercise. METHODS: Eight young, healthy AA women and 9 CA women completed this study. Vascular and hemodynamic measurements were taken at rest, and 5 (P5-1st), 15 (P15-1st), and 30 minutes (P30-1st) following a maximal anaerobic exercise test on cycle ergometer, and 5 (P5-2nd), 15 (P15-2nd), and 30 (P30-2nd) minutes following the second maximal anaerobic exercise test. Brachial systolic (SBP), diastolic (DBP) blood pressures, central aortic SBP, DBP and mean arterial blood pressure (aortic MAP) were measured. Carotid arterial stiffness (beta-stiffness index) were obtained using ultrasonography. RESULTS: Data were presented in Table 1 as mean ± standard error. Resting DBP and aortic DBP were significantly different between AA and CA (§ p<0.05). There was a significant race by time interaction for aortic MAP (* p<0.05). And there was a trend towards significance in race by time interaction for beta stiffness index (p=0.06). CONCLUSION: Acute bouts of anaerobic exercise increase aortic MAP in young AA but not in CA, and it may be related to increases in arterial stiffness in AA. The heightened BP and vascular responses to exercise stimulus may play a role in the pathogenesis of hypertension in AA. Supported by New England ACSM New Investigator Award to HY.Table 1: Hemodynamic responses to two acute bouts of maximal anaerobic exercise.