The definition and assessment of physical activity in cardiovascular risk reduction research

Community-wide promotion of physical activity is becoming increasingly relevant in the development of social, economic, and health-related policy. Such research raises issues in the assessment of physical activity on a population basis. This paper reviews definitions of physical activity for cardiovascular risk reduction and the assessment techniques which arise from them, and makes some recommendations, firstly for the identification of appropriate levels of physical activity, and secondly for the development and selection of assessment techniques. It seems that a clearer conception of appropriate activity levels for fitness and for health will require further research with a range of population groups and activity types. Greater standardisation of questionnaires, improved validity of measures, and a greater understanding of possible response biases will also improve the quality of the basic information on which interventions and policies are developed.