Introduction to Physical Activity Measurement
Physical activity measurement is located at the center of Behavioral Epidemiology Framework because a prerequisite for each research type is the requirement for accurate estimates of the physical activity behaviors. Physical activity measurement methods need to be appropriately selected to address the research questions under consideration, to accommodate the resources available to the researcher, and to be suitable for the population of interest. This chapter aims to provide a comprehensive and contemporary overview of physical activity measurement methods that youth physical activity researchers can use to improve their understanding of the area and guide their decision-making when designing studies. It focuses on the most commonly used youth physical activity measurement methods, which cover self-report, direct observation, pedometers, and accelerometers. The inherent goal with any physical activity measurement method is to capture the true random variation in the physical activity behavior, and minimize other sources of bias and error that obscure the true relationships in the data.