Impact of a Single Bout of Aerobic Exercise on Regional Brain Perfusion and Activation Responses in Healthy Young Adults

Abstract

PurposeDespite the generally accepted view that aerobic exercise can have positive effects on brain health, few studies have measured brain responses to exercise over a short time span. The purpose of this study was to examine the impact within one hour of a single bout of exercise on brain perfusion and neuronal activation.MethodsHealthy adults (n = 16; age range: 20–35 yrs) were scanned using Magnetic Resonance Imaging (MRI) before and after 20 minutes of exercise at 70% of their age-predicted maximal heart rate. Pseudo-continuous arterial spin labeling (pcASL) was used to measure absolute cerebral blood flow (CBF) prior to exercise (pre) and at 10 min (post-10) and 40 min (post-40) post-exercise. Blood oxygenation level dependent (BOLD) functional MRI (fMRI) was performed pre and post-exercise to characterize activation differences related to a go/no-go reaction time task.ResultsCompared to pre-exercise levels, grey matter CBF was 11% (±9%) lower at post-10 (P<0.0004) and not different at post-40 (P = 0.12), while global WM CBF was increased at both time points post-exercise (P<0.0006). Regionally, the hippocampus and insula showed a decrease in perfusion in ROI-analysis at post-10 (P<0.005, FDR corrected), whereas voxel-wise analysis identified elevated perfusion in the left medial postcentral gyrus at post-40 compared to pre (pcorrected = 0.05). BOLD activations were consistent between sessions, however, the left parietal operculum showed reduced BOLD activation after exercise.ConclusionThis study provides preliminary evidence of regionalized brain effects associated with a single bout of aerobic exercise. The observed acute cerebrovascular responses may provide some insight into the brain’s ability to change in relation to chronic interventions.

Exercise intensity modulates the change in cerebral blood flow following aerobic exercise in chronic stroke

“…The novel finding that this response is intensity dependent is in accordance with the notion that somatosensory activity is directly related to the effort of the task (Dettmers et al 1995). We did not observe changes within the insula, a region consistently shown to be particularly sensitive to moderate-intensity exercise (Williamson et al 2004;MacIntosh et al 2014a). The insular effect may be directly related to changes in activation during post-exercise hypotension (Halliwill 2001;Williamson et al 2004), which was not observed in the current study.…”

“…Smith et al (2010) reported a 20 % increase in global CBF up to 30 min following exercise. While our group observed a 33 % increase in white matter CBF within a similar time frame, gray matter CBF was reduced transiently and was unchanged from baseline only 30 min after exercise (MacIntosh et al 2014a). Voxelwise analysis, in the same group of young adults, found increased sensorimotor cortex CBF following moderate exercise (MacIntosh et al 2014a).…”

“…While our group observed a 33 % increase in white matter CBF within a similar time frame, gray matter CBF was reduced transiently and was unchanged from baseline only 30 min after exercise (MacIntosh et al 2014a). Voxelwise analysis, in the same group of young adults, found increased sensorimotor cortex CBF following moderate exercise (MacIntosh et al 2014a). In the current study, we observed exercise effects in the sensorimotor cortices, which were intensity dependent.…”

“…More frequent heart rate and blood pressure measurements, consideration of arterial carbon dioxide (Ito et al 2000), and exercise-related changes in resting-state functional networks (Rajab et al 2014) may help to further establish links between intensity, post-exercise CBF, and acute changes in cognition and motor function. Finally, while there was no spatial overlap between infarcted areas and CBF responses, lesions may have influenced the results by preventing the detection of exercise-sensitive areas previously identified in healthy adults, including the insula (Williamson et al 2004;MacIntosh et al 2014a). Normalized CBF in regions co-registered to ischemic lesions was lower at rest and did not change following exercise.…”

“…Post-exercise, however, CBF is transiently reduced in the insula, anterior cingulate, hippocampus, and thalamus (Williamson et al 2004;MacIntosh et al 2014a). These acute responses in the insula and anterior cingulate, in particular, have shown intensity-dependent characteristics (Williamson et al 2004).…”