Post-exercise hypotension in central aortic pressures following walking and its relation to cardiorespiratory fitness.

BACKGROUND: Central aortic blood pressure (BP) is reduced after exercise. The aim of this study was to determine whether cardiorespiratory fitness relates to post-exercise reductions in aortic BP.

METHODS: Sixteen young adults completed maximal exercise testing for peak oxygen uptake (VO2). Participants walked at a slow (80 steps/min, ~47% maxHR) and fast (125 steps/min, ~65% maxHR) stepping cadence for 3,000 steps on two nonconsecutive days. Before and after each walking condition, radial tonometry was used to derive aortic pressures. Measurements after walking were taken after 30 and 60 min of supine recovery.

RESULTS: The change in aortic BP was similar between walking cadences. Aortic systolic BP (-2.3 mmHg, p=0.03) and pulse pressure (-3.2 mmHg, p<0.001) were significantly reduced after 60 min of recovery as compared to baseline. The reduction in aortic pulse pressure was associated with decreased forward (r=0.69, p<0.001) and backward wave pressure (r=0.70, p<0.001). Peak VO2 was not associated (p>0.05) with these changes, but was strongly associated with non-significant changes in aortic systolic BP (30min: r= -0.54, p=0.03) and diastolic BP (30min: r= -0.64, 60min: r= -0.77; both p<0.01) after slow walking only.

CONCLUSIONS: These results indicate that cardiorespiratory fitness associates with aortic pressure reductions after walking dependent on exercise intensity.