RecruitingBehavioural interventionTBI Rehabilitation and Activation in VeteransThis trial will evaluate the impact of a multicomponent program (TBI Rehabilitation and Activation in Veterans; TRAIN-Vets) on improving cognitive function over an 8-month trial period in older Veterans with traumatic brain injury (TBI). Older Veterans with a history of TBI and subjective cognitive complaints will be enrolled and randomly assign to either the TRAIN-Vets intervention (consisting of aquatic-based exercise training, cognitive training, and lifestyle coaching) or the Health Education Control, where they will receive educational materials about brain health and healthy lifestyles.