The investigators propose a Stage-I randomized controlled trial (RCT) of a remotely-delivered, 16-week social-cognitive theory-based behavioral intervention focusing on combined exercise (aerobic and resistance) training for yielding increases in device-measured physical activity and improvements in cognitive function, symptoms, and quality of life (QOL), and social-cognitive theory (SCT) outcomes among physically inactive persons with Parkinson's disease (PD). Participants (N=50) will be randomly assigned into exercise training (combined aerobic and resistance exercise) condition or active control (flexibility and stretching) condition. The 16-week intervention will be delivered and monitored remotely within a participant's home/community and supported by Zoom-based chats guided by SCT via a behavioral coach. Participants will receive training materials (e.g., prescriptive manual and exercise equipment), one-on-one coaching, action-planning via calendars, self-monitoring via logs, and SCT-based newsletters. The investigators hypothesize that the home-based exercise intervention will yield improvements in cognitive, symptomatic, and QOL outcomes.

Parkinson's disease (PD) is a neurodegenerative disorder of the dopamine-producing nerve cells in the basal ganglia, and age is a primary risk factor for PD. Cognitive impairment is prevalent, disabling, and poorly managed among the 1 million adults living with PD in the United States. Indeed, cognitive impairment begins early in PD, and dementia develops in 80% of persons with PD. Cognitive impairment is further associated with worse fatigue, depression, anxiety, pain, and quality of life (QOL) in PD. Those observations underscore the importance of identifying efficacious approaches for managing cognitive impairment and its consequences, and promoting additional health benefits among those with PD. To date, researchers have examined the benefits of supervised, structured exercise training for managing outcomes of PD, but this approach has clear barriers associated with travel, transportation, and participation (i.e., loss of driving ability, social isolation, and lack of community integration) that are common in PD. The investigators believe that there is merit in the promotion of physical activity for managing cognitive dysfunction and other symptom and QOL outcomes in PD. The investigators offer a novel and innovative approach for promotion of physical activity in PD based on their extensive experiences from Phase I, II, and III randomized controlled trials (RCTs). Those RCTs indicate that the remotely-delivered, social-cognitive theory-based behavioral intervention has successfully increased self-reported and device-measured physical activity in persons with multiple sclerosis (MS). This approach has further resulted in improvements in cognition and walking outcomes, symptoms of fatigue, depression, anxiety, and pain, and QOL among persons with MS. The investigators leverage their experiences and preliminary results in MS, and propose a Stage-I RCT that examines the feasibility and efficacy of a remotely-delivered, theory-based behavioral intervention focusing on combined exercise (aerobic and resistance) training for yielding immediate improvements in device-measured physical activity (primary outcome) among persons with PD who are physically inactive. The investigators further examine the efficacy of this behavioral intervention for improvements in cognitive function, symptoms, and QOL (secondary outcomes). The proposed study, if successful, will provide experiences and pilot data necessary for the design of a subsequent Stage-II RCT that examines the efficacy of the behavioral intervention for immediate and sustained improvements of outcomes in an appropriately-powered and clearly-demarcated sample of adults with PD (i.e., those 50+ years of age who are prescreened for cognitive impairment). This line of research may yield "real-world" guidelines for physical activity that can be implemented for the treatment of cognitive dysfunction and other outcomes in PD. Such an opportunity for rehabilitation of cognitive function using an approach with broad reach and scalability is paramount considering the prevalent, disabling, and poorly managed nature of cognitive impairment in PD and limited efficacious resources for its treatment.

Inclusion Criteria:

• confirmed diagnosis of PD
• Internet and email access
• willingness to complete the cognitive assessments and questionnaires, wear the accelerometer, and undergo randomization
• insufficient physical activity (i.e., not meeting current physical activity guidelines) based on a health contribution score of less than 14 units from the Godin Leisure-Time Exercise Questionnaire
• self-reported ability to ambulate without assistance
• age of 50+ years
• English as a primary language
• asymptomatic (i.e., one or fewer affirmatives on the Physical Activity Readiness Questionnaire [PAR-Q]) or physician approval for undertaking exercise training for those with 2 or more affirmatives on the PAR-Q

Exclusion Criteria:

• above inclusion criteria not met
• moderate or high risk of contraindications for possible injury or death when undertaking strenuous or maximal exercise using the PAR-Q
• severe cognitive impairment that might preclude compliance with the conditions based on a modified Telephone Interview for Cognitive Status (TICS-M) score of less than 18
• normal cognitive impairment based on the Montreal Cognitive Assessment (MoCA) score of 26 or more for avoiding ceiling effects involving change in cognitive function