Inclusion Criteria:  ≥50 years of age; females must be post-menopausal Presence of cerebrovascular and/or cardiovascular risk factors or coronary artery disease Montreal Cognitive Assessment (MoCA) <27 Sufficiently proficient in English Must be able to exercise at a moderate intensity level Presence of modest deficits (1 standard deviation below population norm) in one of the following domains: executive function, verbal memory, working memory, or visuospatial memory  Exclusion Criteria:  History of stroke Change in psychotropics within the last 4 weeks Current benzodiazepine use due Metal implants that would preclude safe use of tDCS or neuroimaging Significant neurological or psychiatric conditions (current major depressive disorder, bipolar disorder, schizophrenia) MoCA <18 and/or clinical diagnosis of dementia Any medical contraindications to exercise