ABSTRACT
Physical inactivity is identified as the fourth leading risk factor for global mortality. Consequently, surveillance of physical activity/inactivity is important for understanding the scope and distribution of the public health impact, and informing and assessing future strategies and interventions. Physical activity surveillance relies on objective and subjective measurement methods for the assessment of physical activity among children and youth. Objective methods of assessing physical activity include measures based on energy expenditure or oxygen uptake, heart rate monitoring, and motion sensors using accelerometry, or pedometers measuring step counts. The surveillance of the physical activity of children and youth at the population level is challenged by this trade-off between accuracy and feasibility. Questionnaires are today the most commonly used tools to evaluate physical activity at the population level. Insufficient levels of physical activity have been observed internationally among children and youth raising concerns for their general health and for the future prevalence of non-communicable diseases.
