Estimating physical activity level: the role of domestic activities.

A ppropriate measures of physical activity are essential for determining the population prevalence of physical activity, for tracking trends over time, and for guiding intervention efforts. Physical activity measurement is characterised by the synthesis of information on the type, frequency, intensity, and duration of activity over a specified period. To date, emphasis in physical activity assessment has been on the measurement of leisure time physical activities. However, some domestic and transport related activities entail energy expenditures equivalent to moderate intensity of 3.0–6.0 METS considered to be of sufficient intensity to achieve a health benefit are yet to be included in routine population level physical activity surveillance. This leads to population estimates based only on measures of leisure time physical activities. Recent developments in research on the energy expenditure of domestic activities have highlighted the potential contributions of these activities to health. Given that domestic activities may be the major source of energy expenditure for certain population groups, determining their relative contribution to the total activity level is an important step to demonstrating independent health benefits of engaging in domestic activities. We conducted additional analyses of the 1998 New South Wales (NSW) state Health Survey in Australia to examine the impact of including combined measures of ‘‘vigorous household chores and gardening activities’’ as well as leisure time physical activities on the population estimates of health enhancing physical activity.