Tailored Online Physical Activity Coaching for Middle-Aged and Older Adults With Cognitive and Mental Health Concerns: Single-Arm Pre-Post Intervention Study

Only 6% of participants met all applicable physical activity guidelines at the start of the program; by the end, 44% met these guidelines — a more than seven-fold increase. Participants were at least eight times more likely to meet age-appropriate guidelines for aerobic, strength and balance activities after the intervention, despite beginning with activity levels far below the Australian population average.

Depression, anxiety and stress symptoms all improved significantly and with large effect sizes (depression d=−1.31, stress d=−1.18, anxiety d=−0.89). Over 12 weeks, mean depression and stress scores shifted from the severe to the mild range, and anxiety scores moved from moderate to within the normal range. These are clinically meaningful changes for a population that experiences well-documented barriers to physical activity participation due to their mental health symptoms.

Participants experienced a statistically significant reduction in overall dementia risk (d=−0.32, P=.008) as measured by the validated CogDRisk tool. This adds to a growing body of evidence that physical activity can reduce dementia risk in high-risk populations, including those with co-occurring cognitive concerns and mental health symptoms, and demonstrates that increasing dementia knowledge is not a prerequisite for reducing dementia risk.

The program achieved a 95% completion rate, with 98% of completers rating the program as useful and 100% indicating they would recommend it to others. Safety was successfully managed through a system of email alerts and clinical panel oversight without requiring coaches to hold mental health or exercise physiology credentials themselves. These findings challenge the assumption that age is a barrier to engaging with safe and effective online physical activity interventions.

All 52 program completers rated the fortnightly online catch-up sessions as helpful to very helpful, with 79% rating them as very helpful. Attendance at these sessions was very high (89% attended all six sessions). This highlights the importance of regular, personalised contact in sustaining motivation and addressing barriers for this population, and suggests this component is central to the program's acceptability.

Significant improvements were observed in action planning (d=0.66, P=.001) and positive outcome expectancies for exercise (d=0.33, P=.02). These two cognitive mechanisms — forming concrete plans for when, where and how to exercise, and believing exercise will lead to positive outcomes — appear to play a key role in helping participants translate intentions into consistent physical activity, in line with the COM-B behaviour change framework underpinning the intervention.

Fifty-two per cent of participants moved from a lower to a higher stage of behavioural readiness, with average scores shifting from the "preparation" stage to the "action" stage. All participants who began at stage 2 (intending to start) or stage 3 (started but not regular) progressed to a later stage, suggesting the program is particularly effective at supporting people at the earlier stages of readiness to exercise.

Yes — The design of the EXCEL intervention was informed by Phase 1 of the EXCEL study, which included semistructured interviews with 21 participants to identify their needs, preferences and barriers related to physical activity. These insights shaped the tailoring of the program to address emotional regulation, confidence-building and overcoming barriers to translating intention into action. In Phase 2 (this study), participant perspectives were also captured through a post-intervention evaluation questionnaire assessing enjoyment, usefulness and usability of the program.

Yes — The intervention was designed and delivered by a multidisciplinary team including coaches from psychology, physical activity, social work and occupational therapy, with clinical oversight from psychiatrists and exercise physiologists. Coaches applied individualised behaviour change strategies — including education, motivation, reinforcement, environmental restructuring and enablement — based on clinical judgment and knowledge of each participant's needs. A clinical panel met fortnightly to monitor safety, and an exercise specialist provided additional support to participants as needed.

Yes — This paper is a single-arm pre-post pilot study evaluating the EXCEL intervention against primary and secondary outcomes including physical activity guideline adherence, dementia risk, mental health symptoms, stages of change, and cognitive mechanisms of behaviour change. The intervention was grounded in a published behaviour change framework (COM-B model), existing physical activity guidelines for older adults, and prior research on the AIBL Active Study and INDIGO trial. Quantitative analyses using validated instruments (CHAMPS, DASS-21, CogDRisk, and others) provide the primary evidence base.