This 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.

The purpose of the proposed trial is to evaluate the impact of a multicomponent training program (TRAIN-Vets) on improving cognitive function and other outcomes over an 8-month period in older Veterans with TBI and cognitive complaints. The primary aim of the trial is to evaluate the efficacy of the TRAIN-Vets intervention to improve cognitive function in Veterans with TBI. Secondary aims of the proposed research are to evaluate the efficacy of TRAIN-Vets to improve: 1) individual cognitive domain scores, 2) psychological and social measures (sleep, mood, social and community engagement, diet, and life satisfaction), and 3) physical fitness.

The investigators will randomize 120 older Veterans with TBI and cognitive complaints aged 50 or older to TRAIN-Vets or Health Education Control (HEC). Participants randomized to the TRAIN-Vets group will engage in aquatic-based exercise training and cognitive training combined with personalized risk factor reduction related to their brain health risk factors. This intervention entails 6 months of thrice-weekly aquatic-based exercise training at Veterans Affairs Palo Alto Health Care System (VAPAHCS). After completion of the 6-months of exercise training, Veterans in this condition will participate in 2 months of weekly structured on-line cognitive training focused on improvement of executive function and attention based out of the San Francisco Veterans Affairs Health Care System (SFVAHCS). Over the 8 months, Veterans in TRAIN-Vets will also participate virtually in monthly personalized risk reduction sessions based at SFVHCS focused on improving other risk factors and symptoms. Participants in the HEC group will be mailed educational materials about brain health and dementia risk factor reduction throughout the 8 months. HEC participants will be contacted monthly through phone calls to check in and maintain interest. All participants will complete a phone screening, baseline in person and virtual visits, and follow-up visits with blinded assessors (to assess outcomes) at approximately 6 and 8 months.

Inclusion Criteria:

• Veteran, age 50-89 years
• History (more than 6 months post injury) of mild or moderate TBI defined by the Ohio State University TBI Identification Method and DOD/VA Clinical Practice Guidelines for Definition of TBI
• Sufficient vision and hearing to allow cognitive testing
• Willingness to participate in water-based exercise program + cognitive training program for eight months
• Approval of primary medical provider to participate in a water-based exercise program
• Subjective cognitive complaints as evidenced by self-report
• English proficiency to allow for cognitive testing
• Internet connected device to participate in testing and cognitive training

Exclusion Criteria:

• Current severe and unstable psychiatric disorder
• Diagnosis of dementia, Montreal Cognitive Assessment score less than 18, or delirium
• TBI within the past 6 months
• Acute illness or unstable chronic illness
• Current severe cardiac disease
• Severe TBI or open head injury
• Inability to exercise consistently
• Inability to read, verbalize understanding, and voluntarily sign the Informed Consent