Large-scale accelerometry-derived physical activity and sedentary behaviour assessmentsin relation to health characteristics and outcomes among participants of the Lifelines Biobank study: rationale and design of the ActiveLIFE cohort study

Introduction: Current guidelines on physical activity (PA) and sedentary behaviour (SB) are based on self-reported questionnaire data, which are prone to recall bias and measurement error. As such, they provide limited guidance on the intensity, frequency and duration of activities. To improve and accelerate research on the health benefits of a physically active lifestyle and inform future guidelines, large-scale accelerometry in population-based studies is needed. The ActiveLIFE cohort study aims to create a comprehensive, deeply-phenotyped dataset of thigh- and wrist-worn accelerometry in relation to health characteristics and outcome data that can be used to accelerate lifestyle and prevention research. Methods and analysis: ActiveLIFE is an add-on study to the 4th assessment wave of the Lifelines Biobank study, aiming to collect ~60,000 accelerometry measurements. Lifelines participants aged [≥]8 years old will be invited to wear a triaxial thigh-worn accelerometer (Axivity AX3, settings: 100 Hz, 8g) for 8 consecutive days. Morover, to evaluate how wear location impacts effect estimates, a subsample of at least 10% will be asked to wear both a thigh- and wrist-worn accelerometer. Raw accelerometry data will be processed into PA metrics, including steps per day, time spent in moderate-to-vigoruous PA, light-intensity PA, SB, and sleep and enriched with data on demographics, body composition, health status, medication use, lifestyle characteristics, biomarkers, cognitive function, cardiopulmonary performance, genetics, healthcare consumption and health outcome data. ActiveLIFE will allow to further refine, extend and personalize future guidelines on PA and SB for optimal PA prescription. Ethics & dissemination: Ethics approval for the Lifelines Biobank, including the ActiveLIFE add-on study, was obtained from the Medical Ethics Committee of the University Medical Centre Groningen, the Netherlands (#2007/152). Informed consent was obtained from all participants. Study findings will be disseminated through peer-reviewed publications and conference presentations, and societal outreach approaches.