Adherence

Physical activity questionnaires (PAQs) and accelerometers demonstrate moderate validity for assessing total physical activity and moderate-to-vigorous physical activity (MVPA) in epidemiologic studies, with PAQs showing particularly strong correlations for vigorous activity.

For researchers and clinicians, using a well-designed physical activity questionnaire (PAQ) is a valid and scalable method for assessing moderate-to-vigorous physical activity in large groups, especially when gold-standard biomarkers like doubly labeled water are too costly. While accelerometers are useful, they may miss certain activities (like swimming or biking) and showed lower validity for vigorous activity compared to PAQs in this study. Combining methods or using validated questionnaires provides a robust estimate of physical activity levels for epidemiological purposes.