Physical Activity


Measuring Physical Activity in the General Population
Physical Activity Frequency Questionnaire


Physical activity protects against coronary heart diseases. The greatest benefits seem to occur among subjects who are moderately active compared to sedentary people, probably because, in today's life of westernized population, most of the energy is spent in light and moderate intensity activities such as office work, watching television, or driving. Therefore, measuring total energy expenditure may be crucial for understanding the connection of physical activity to diseases and to frame public health intervention.

Measuring total energy expenditure using questionnaire raises important methodological problems. While heavy intensity leisure activities, such as soccer, aerobics or running, are usually performed on a regular basis and associated with a well-known nomenclature, light and moderate activities tend to vary more and their nomenclature is less standard ( e.g., domestic activities, handy work or office work). These activities belong to a routine and may not be well recalled if not over a recent period.

To be used in the Geneva Bus Santé project, we developed a self-administered physical activity frequency questionnaire (PAFQ), to measure total and activity-specific energy expenditure in sub-goups of the population, with special attention to light and moderate intensity activities. The methodology was inspired by the similarity between physical activity and diet from the perspective of behavioral assessment. The major sources of energy expenditure and their typical duration were identified using 24-hour recalls of physical activity.

The article, which abstract is below, describeds, step by step, the development of the instrument and its validation relative to a more objective measure of energy expenditure, a heart rate monitor method. The project was funded by the Swiss National Science Foundation. (N°3200-037986.93)


A Data-Based Approach for Developing a Physical Activity Frequency
Bernstein M , Sloutskis D , Kumanyika S , Sparti A , Schutz Y , Morabia A
American Journal of Epidemiology, 1998, Vol 47, N°2, p:147-154


Measuring total energy expenditure may be crucial for understanding the connection of physical activity to diseases and to frame public health intervention. To devise a self-administrated, physical activity frequency questionnaire (PAFQ), the following data-based approach was used. A 24-hour recall was administered to a random sample of 919 adults, residents of Geneva, Switzerland. The data obtained were used to establish the list of activities (and their median duration) contributing to 95 percent of the energy expended, separately for men and women. Activities that were trivial for the whole sample but that contributed to 10% or more of individual’s energy expenditure, were also selected. The final PAFQ lists 70 activities or group of activities with their typical duration. About 20 minutes are required for respondents to indicate the number of days, and the number of hours per day, they performed each activity. The PAFQ was validated against heart rate monitors, a more objective method. The total energy estimated by the PAFQ in 41 volunteers correlated well (R= 0.76) with estimates using a heart rate monitor. The design of a PAFQ based on data from 24-hour recalls appears to accurately estimate energy expenditure.