Table 1.

Potential association between physical activity and cerebral collateral circulation recruitment.

Factors influencing cerebral collateral circulation	Proposed benefits of physical activity
Collateral vessel anatomical variations, size, number, and distribution (27, 29)	Promoting growth of new arteriole blood vessels via vascular endothelial growth factors (52, 53)
Capacity to vasodilate (30) • Endothelial function and nitric oxide bioavailability (26)	Cerebrovascular adaptations • Increase nitric oxide bioavailability (54, 55) • Increased cerebral blood flow and reactivity (56)
Individual risk factors • Older age (13, 29) • Metabolic syndrome (16) • Hypertension (47) • Pre-stroke statin treatment (48)	Reduce individual risk factors (57) • Hypertension • Type 2 diabetes • Cardiovascular disease • Obesity