AUTHOR=Kleinloog Jordi P. D. , Mensink Ronald P. , Ivanov Dimo , Adam Jos J. , Uludağ Kamil , Joris Peter J. 

TITLE=Aerobic Exercise Training Improves Cerebral Blood Flow and Executive Function: A Randomized, Controlled Cross-Over Trial in Sedentary Older Men

JOURNAL=Frontiers in Aging Neuroscience

VOLUME=11

YEAR=2019

URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2019.00333

DOI=10.3389/fnagi.2019.00333

ISSN=1663-4365

ABSTRACT=<sec><title>Background</title><p>Physical activity may attenuate age-related cognitive decline by improving cerebrovascular function. The aim of this study was therefore to investigate effects of aerobic exercise training on cerebral blood flow (CBF), which is a sensitive physiological marker of cerebrovascular function, in sedentary older men.</p></sec><sec><title>Methods</title><p>Seventeen apparently healthy men, aged 60–70 years and with a BMI between 25 and 35 kg/m<sup>2</sup>, were included in a randomized, controlled cross-over trial. Study participants were randomly allocated to a fully-supervised, progressive, aerobic exercise training or no-exercise control period for 8 weeks, separated by a 12-week wash-out period. Measurements at the end of each period included aerobic fitness evaluated using peak oxygen consumption during incremental exercise (VO<sub>2</sub><sub>peak</sub>), CBF measured with pseudo-continuous arterial spin labeling magnetic resonance imaging, and post-load glucose responses determined using an oral glucose tolerance test (OGTT). Furthermore, cognitive performance was assessed in the domains of executive function, memory, and psychomotor speed.</p></sec><sec><title>Results</title><p>VO<sub>2</sub><sub>peak</sub> significantly increased following aerobic exercise training compared to no-exercise control by 262 ± 236 mL (<italic>P</italic> &lt; 0.001). CBF was increased by 27% bilaterally in the frontal lobe, particularly the subcallosal and anterior cingulate gyrus (cluster volume: 1008 mm<sup>3</sup>; <italic>P</italic> &lt; 0.05), while CBF was reduced by 19% in the right medial temporal lobe, mainly temporal fusiform gyrus (cluster volume: 408 mm<sup>3</sup>; <italic>P</italic> &lt; 0.05). Mean post-load glucose concentrations determined using an OGTT decreased by 0.33 ± 0.63 mmol/L (<italic>P</italic> = 0.049). Furthermore, executive function improved as the latency of response was reduced by 5% (<italic>P</italic> = 0.034), but no changes were observed in memory or psychomotor speed.</p></sec><sec><title>Conclusion</title><p>Aerobic exercise training improves regional CBF in sedentary older men. These changes in CBF may underlie exercise-induced beneficial effects on executive function, which could be partly mediated by improvements in glucose metabolism. This clinical trial is registered on <ext-link ext-link-type="uri" xlink:href="https://clinicaltrials.gov" xmlns:xlink="http://www.w3.org/1999/xlink">ClinicalTrials.gov</ext-link> as NCT03272061.</p></sec>