Ebola, dynamin, and the Cordon Sanitaire of Dr. Adrien Proust

Dietary nitrate increases middle cerebral artery mean velocity (MCA Vmean) during aerobic exercise but it remains unclear if this is true with the simultaneous inclusion of a cognitively demanding task. Therefore, our aim was to investigate whether nitrate supplementation would influence exercise-induced changes in MCA Vmean, and cognitive performance. In a double blind randomized crossover design, 12 healthy adults consumed two 70 ml doses of either beetroot juice or placebo two hours prior to exercise. Subjects then completed four 8-min workloads of exercise set to elicit 30%, 50%, 70%, and 85% of heart rate reserve (HRR) on a cycle ergometer. Reaction time and accuracy was assessed during a modified version of the color Stroop task, with simple and complex (incongruent) response types, in the last 3 min of each workload. MCA Vmean (Transcranial Doppler) was monitored throughout. MCA Vmean displayed a typical relationship with exercise intensity, but was significantly elevated with beetroot, especially during the complex Stroop task, at 70% (p=0.001, d=0.47) and 85% HRR (p=0.027, d=0.74). Reaction time was not statistically different between conditions regardless of the difficulty level. However, beetroot may have contributed to increased accuracy in the complex task (p=0.059) whilst cycling. These preliminary results suggest that dietary nitrate elevates MCA Vmean during a combined exercise and cognitive challenge, which may be related to improved accuracy during the most demanding tasks.