Purpose: To measure endothelial function and oxidative stress immediately, 90 minutes, and three hours after exercise of varying intensities.
Methods: Sixteen apparently healthy men completed three exercise bouts of treadmill running for 30 minutes at 55% V̇O(2max) (mild); 20 minutes at 75% V̇O(2max) (moderate); or 5 minutes at 100% V̇O(2max) (maximal) in random order. Brachial artery flow-mediated dilation (FMD) was assessed with venous blood samples drawn for measurement of endothelin-1 (ET-1), lipid hydroperoxides (LOOHs), and lipid soluble antioxidants.
Results: LOOH increased immediately following moderate exercise (P < 0.05). ET-1 was higher immediately after exercise and 3 hours after exercise in the mild trial compared to maximal one (P < 0.05). Transient decreases were detected for ΔFMD/Shear(AUC) from baseline following maximal exercise, but it normalised at 3 hours after exercise (P < 0.05). Shear rate was higher immediately after exercise in the maximal trial compared to mild exercise (P < 0.05). No changes in baseline diameter, peak diameter, absolute change in diameter, or FMD were observed following any of the exercise trials (P > 0.05).
Conclusions: Acute exercise at different intensities elicits varied effects on oxidative stress, shear rate, and ET-1 that do not appear to mediate changes in endothelial function measured by FMD.