Aerobic exercise training is known to have beneficial impacts on numerous body functions. It’s the best pill on the market ! However, although a high aerobic fitness seems to be associated with higher cerebral blood flow in trained individuals vs. sedentary subjects (cross-sectional study), the influence of aerobic exercise training on cerebral blood flow remains ambiguous.
A recent study investigated the effects of 8 weeks of aerobic exercise training on cerebral blood flow velocity in post-menopausal women. Exercise training consisted in walking/cycling 3-6 days/week, 30-60 min/session at an intensity of 60 to 75% of maximal heart rate. A control group did not change their physical activity level during these 8 weeks.
Cerebral blood flow velocity in left and right middle cerebral arteries (transcranial Doppler), cerebrovascular resistance, arterial blood pressure (photoplethysmography), and blood biochemistry parameters were measured before and following aerobic exercise training.
The figures below show the main results of this study.
As you can see, blood flow velocity in the middle cerebral artery increased while cerebrovascular resistance lowered after 8 weeks of aerobic exercise training. The authors suggest that both structural (angiogenesis) and functional (improvement in endothelial function) changes in the brain vessels following aerobic exercise training could explain this elevation in cerebral blood flow velocity.
Since PaCO2 and cardiac output are important determinants of cerebral blood flow, it could have been interesting for the authors to include these measurements…especially cardiac output if they used the Finapres to measure arterial blood pressure !
But anyway, this is a good start and we definitely need to conduct further studies to better understand the impact of aerobic exercise training on cerebral blood flow !
Akazawa N, Choi Y, Miyaki aA, Sugawara J, Ajisaka R, Maeda S. (2012). Aerobic exercise training increases cerebral blood flow in postmenopausal women. Artery Research, 6(3), 124–129. doi:10.1016/j.artres.2012.05.003