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Impact of aerobic fitness on cerebral blood flow and cerebral vascular responsiveness to CO 2 in young and older men
Author(s) -
Braz I. D.,
Flück D.,
Lip G. Y. H.,
Lundby C.,
Fisher J. P.
Publication year - 2017
Publication title -
scandinavian journal of medicine and science in sports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.575
H-Index - 115
eISSN - 1600-0838
pISSN - 0905-7188
DOI - 10.1111/sms.12674
Subject(s) - cerebral blood flow , aerobic exercise , medicine , cardiology , physical fitness , physical therapy , physical medicine and rehabilitation
We sought to test the hypothesis that brain blood flow and cerebral vascular responsiveness to carbon dioxide (CVR CO2 ) are greater in aerobically trained young and old individuals compared to their untrained counterparts. In 11 young trained {[23 (20–26) years] [mean (95% confidence interval)]}, 10 young untrained [25 (22–28) years], 8 older trained [65 (61–69) years], and 9 older untrained [67 (64–71) years] healthy individuals, Doppler ultrasound of the internal carotid ( ICA ) and vertebral ( VA ) artery blood flow were determined, along with middle cerebral artery mean flow velocity ( MCA V mean ). Bilateral ICA blood flow was higher in trained individuals when compared to untrained (≈31%, P < 0.05), but was not influenced by age. VA blood flow was not affected by age or cardiorespiratory fitness. MCA V mean was reduced with age [59.5 (55.0–64.1) cm/s young vs 43.6 (38.4–48.9) cm/s old, P < 0.05] with no significant effect of training observed. MCA CVR CO 2 were not significantly affected by either age or training status, while ICA CVR CO 2 tended to be elevated in the old trained group. These findings indicate that endurance training enhances bilateral ICA but not VA blood flow in both young and older individuals.