Cerebral blood flow regulation, central arterial stiffness and traumatic brain injury: Effects of aerobic exercise training.

Advanced age is the strongest risk factor for Alzheimer's disease and related dementias (ADRDs). Traumatic brain injury (TBI) has also been recognized as a risk factor for ADRD, potentially contributing to an earlier onset of the disease. Thus, elucidating the mechanisms underlying brain ageing and TBI is critical for developing strategies to preserve brain health. Accumulating evidence indicates that arterial ageing, manifested as increased central arterial stiffness, is closely associated with cerebral blood flow (CBF) dysregulation and brain ageing, whereas improvement of CBF regulation through aerobic exercise training contributes to brain health. Emerging studies suggest that central arterial stiffness is elevated after TBI but can be ameliorated by aerobic exercise training, which benefits TBI recovery. In this brief review, we summarize evidence demonstrating that (1) age- or TBI-related increases in central arterial stiffness are associated with CBF dysregulation, and (2) aerobic exercise training improves CBF regulation by reducing central arterial stiffness in both healthy older adults and individuals with chronic TBI. Collectively, these findings support the hypothesis that central arterial stiffness impacts CBF regulation and highlight aerobic exercise as a promising intervention for preserving brain health in ageing and after TBI.