A guide for clinicians – physical activity and energy expenditure explained

Abstract

Background: Regular physical activity (PA) is a key component in the maintenance of a healthy lifestyle and is known to decrease the risk of numerous chronic health conditions. Accurate measurement of PA is essential to determine the effect of exercise interventions on long-term PA levels and to identify population health behaviours. However, measurement of PA is complex and multimodal with numerous measurement tools available. Objectives: The aim of this review is to improve conceptual clarity regarding PA and to examine the difficulties relating to PA measurement in order to enable clinicians to choose the optimal PA measurement tool. Major findings: PA is a multidimensional concept. Movement and energy expenditure (EE) are the most common dimensions used in the quantification of PA. There are numerous PA measurement options including doubly labelled water, calorimetry, heart rate monitors and motion sensors (pedometers and accelerometers). Choosing the optimal measurement tool is influenced by the parameter of PA that is of most relevance. Motion sensors appear to provide the most promising and accurate cost-effective method of measuring free-living PA, particularly when accelerometer and physiological data are integrated. However, consideration must be given to the intrinsic difficulties associated with motion monitors, particularly the use of generic values and algorithms in calculating EE, which limit the external validity and applicability of motion sensors in different populations. Conclusions: Although the optimal method of measuring PA remains unknown, forming appropriate research and clinical questions and providing conceptual clarity should guide clinicians in selecting the most appropriate measurement option.

Physical activity monitoring for health

“…O'Dwyer and Coote give advice to clinicians regarding the optimal tool to measure physical activity. 1 The starting point is the definition of physical activity from Caspersen et al, 'any bodily movement produced by skeletal muscles that results in energy expenditure'. 2 Consequently, the reference for a tool to measure physical activity is energy expenditure, more specifically one of the three components of total energy expenditure (TEE), i.e.…”