The effect of changes in cerebral blood flow on cognitive function during exercise

Abstract

No studies have identified the direct effect of changes in cerebral blood flow (CBF) on cognitive function at rest and during exercise. In this study, we manipulated CBF using hypercapnic gas to examine whether an increase in CBF improves cognitive function during prolonged exercise. The speed and the accuracy of cognitive function were assessed using the Stroop color‐word test. After the Stroop test at rest, the subjects began exercising on a cycling ergometer in which the workload was increased by 0.5 kilopond every minute until a target heart rate of 140 beats/min was achieved. Then, the subjects continued to cycle at a constant rate for 50 min. At four time points during the exercise (0, 10, 20, 50 min), the subjects performed a Stroop test with and without hypercapnic respiratory gas (2.0% CO2), with a random order of the exposures in the two tests. Despite a decrease in the mean blood flow velocity in the middle cerebral artery (MCA Vmean), the reaction time for the Stroop test gradually decreased during the prolonged exercise without any loss of performance accuracy. In addition, the hypercapnia‐induced increase in MCA Vmean produced neither changes in the reaction time nor error in the Stroop test during exercise. These findings suggest that the changes in CBF are unlikely to affect cognitive function during prolonged exercise. Thus, we conclude that improved cognitive function may be due to cerebral neural activation associated with exercise rather than global cerebral circulatory condition.

Cognitive performance is associated with cerebral oxygenation and peripheral oxygen saturation, but not plasma catecholamines, during graded normobaric hypoxia

“…() by providing the first experimental evidence, using a rigorous, within‐subject design, that n ‐back performance (a task requiring executive function) is associated with both peripheral arterial oxygen desaturation and oxygenation of the PFC. Oxygenation of the PFC is also affected by cerebral vasoconstriction caused by hypoxia‐induced hyperventilation (Ogoh et al., ; Steinback & Poulin, ). Although we observed a significant alteration in , the magnitude of change was small (3 mmHg).…”

Maintained exercise‐enhanced brain executive function related to cerebral lactate metabolism in men

“…On the day of the experiment, subjects had a standard light meal (580 kcal) 2 h before the first HIIE. Subsequently, the subject practiced the CWST 10-15 times to ensure that they were familiar with the test and then rested until the start of the experiment (9). Next, the subjects performed the preexercise CWST and, subsequently, the HIIE protocol (first HIIE).…”

The interactive effects of acute exercise and hypoxia on cognitive performance: A narrative review

“…However, several studies indicated that increases in middle cerebral artery (MCA) blood flow mean velocity, measured by transcranial Doppler, are not related to changes in cognitive performance. 22,[68][69][70] Although changes in MCA diameter under hypocapnic and hypercapnic conditions 71,72 might skew these results, it is likely that alterations in CBF are not directly associated with such improvements. 15 Nevertheless, given that CBF contributes to the increase in cerebral oxygen delivery during exercise, the absence of an association does not mean that increased CBF is not somewhat responsible for cognitive improvements.…”

“…One may argue that increased CBF contributes to cognitive improvement induced by acute exercise. However, several studies indicated that increases in middle cerebral artery (MCA) blood flow mean velocity, measured by transcranial Doppler, are not related to changes in cognitive performance . Although changes in MCA diameter under hypocapnic and hypercapnic conditions might skew these results, it is likely that alterations in CBF are not directly associated with such improvements .…”