Habitual exercise provides repeated episodes of elevated vascular shearstress (SS), which may be a mechanism for repair of endothelial dysfunction in disease.Our aim was to determine the brachial artery SS during the 3–hour period followingsingle bouts of low, moderate, and high-intensity walking exercise. In a randomized crossover design, 14 men walked for 45 minutes on a treadmill at 25%, 50% and 75% of VO2peak separated by 2–7 days. Using Doppler ultrasonography, brachial artery SS was assessed immediately after exercise and then hourly for 3 hours. Highintensity walking elicited greater (p <0.05) post-exercise SS compared with low and moderate intensity. In addition, a 3 × 4 (intensity × time) ANOVA indicated an absence of interaction (p = 0.369) and a decline in post-exercise SS over time (p <0.0001) which was abolished after 2 hours. Thus, we found that brachial artery SS is greatestfollowing high-intensity walking and that the rate of decline in SS is similar across allwalking intensities.
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- Doppler ultrasonography
- endothelial function
- exercise intensity