Neurovascular coupling and cerebrovascular hemodynamics are modified by exercise training status at different stages of maturation during youth.

Neurovascular coupling (NVC) is mediated via nitric oxide signaling, which is independently influenced by sex hormones and exercise training. Whether exercise training differentially modifies NVC pre- versus postpuberty, where levels of circulating sex hormones will differ greatly within and between sexes, remains to be determined. Therefore, we investigated the influence of exercise training status on resting intracranial hemodynamics and NVC at different stages of maturation. Posterior and middle cerebral artery velocities (PCA_v and MCA_v) and pulsatility index (PCA_PI and MCA_PI) were assessed via transcranial Doppler ultrasound at rest and during visual NVC stimuli. N ¼ 121 exercise-trained (males, n ¼ 32; females, n ¼ 32) and untrained (males, n ¼ 28; females, n ¼ 29) participants were characterized as pre (males, n ¼ 33; females, n ¼ 29)- or post (males, n ¼ 27; females, n ¼ 32)-peak height velocity (PHV). Exercise-trained youth demonstrated higher resting MCA_v (P ¼ 0.010). Maturity and training status did not affect the DPCA_v and DMCA_v during NVC. However, pre-PHV untrained males (19.4 ± 13.5 vs. 6.8 ± 6.0%; P ≤ 0.001) and females (19.3 ± 10.8 vs. 6.4 ± 7.1%; P ≤ 0.001) had a higher DPCA_PI during NVC than post-PHV untrained counterparts, whereas the DPCA_PI was similar in pre- and post-PHV trained youth. Pre-PHV untrained males (19.4 ± 13.5 vs. 7.9 ± 6.0%; P ≤ 0.001) and females (19.3 ± 10.8 vs. 11.1 ± 7.3%; P ¼ 0.016) also had a larger DPCA_PI than their pre-PHV trained counterparts during NVC, but the DPCA_PI was similar in trained and untrained post-PHV youth. Collectively, our data indicate that exercise training elevates regional cerebral blood velocities during youth, but training-mediated adaptations in NVC are only attainable during early stages of adolescence. Therefore, childhood provides a unique opportunity for exercise-mediated adaptations in NVC.