Abstract
INTRODUCTION: With the global population ageing rapidly, older adults face increased risks of physical and cognitive decline. Despite the well-documented benefits of physical activity (PA), many older adults fail to meet PA guidelines. Mobile health (mHealth) apps offer promising tools to promote PA, but user engagement remains a challenge. In response, the MIA app was co-created with older adults using the Behavior Change Wheel framework to enhance usability, relevance and sustained engagement. A feasibility study showed promising results in usability and user satisfaction, supporting further evaluation. The goal of this study is to evaluate the effectiveness of MIA on PA promotion in older adults. METHODS AND ANALYSIS: A randomised controlled trial conducted in Belgium at a university college will assess the effectiveness of the MIA app in promoting PA in older adults. Participants will be randomly assigned in a 1:1 ratio to either the intervention group (MIA app use) or the control group (no use of MIA) for 8 weeks. The primary outcome is moderate-to-vigorous PA, measured via Garmin wearable devices. Secondary outcomes include self-reported measures (PA, well-being, user satisfaction), clinical assessments (physical and cognitive functioning) and time series assessments (daily steps). A total of 75 participants will be recruited to ensure sufficient power, accounting for dropout. Eligible participants must be ≥65 years, medically stable, have no significant cognitive or physical limitations, understand and speak Dutch and have access to a smartphone and/or computer. Exclusion criteria include an active lifestyle, participation in other exercise programmes or clinical trials, or any condition deemed by a healthcare professional to compromise safety or study validity. ETHICS AND DISSEMINATION: The study was approved by the UHasselt Medical Ethics Committee (B1152025000012) and complies with Belgian legislation on human research. Written informed consent will be obtained from all participants prior to enrolment. Data will be securely stored for up to 25 years. Results will be disseminated via peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT06983574.