Ethnic and cultural issues in assessing physical activity.

Although the physical activity questionnaire, in general, is the most common measure of physical activity levels in minority subgroups, additional measures may be needed to supplement the information collected by questionnaire alone. The most frequent types of physical activities performed in many of these minority groups are often lower intensity activities. However, when assessing activity by questionnaire, we know that lower intensity activities like walking and housework tend to be less reproducible than higher intensity activities such as many of the organized sports (Kriska et al., 1990; Sallis et al., 1985). Therefore, the activity questionnaire alone may not be the best way to quantify these lower intensity, variable frequency, life-style activities. As Figure 3 reminds us, measurement of lower intensity activities may require the use of more objective measures. One feasible approach may be to use a simple, inexpensive, objective measure of activity like an activity monitor or a pedometer. Step monitors are now successfully being used to estimate levels of movement expressed as "daily steps taken throughout the day" and to document activity changes in intervention efforts. However, activity monitors also have their own set of limitations such as the inability of capturing cycling, swimming, and upper body movement. Likewise, monitors certainly are not as practical as physical activity questionnaires in assessing activity in population studies. It is likely that a combination of the two methods of activity assessment would work best. Individuals who have scored low on the activity questionnaire could be given a step monitor to further evaluate their physical activity levels. Although promising, much more work needs to be done in this area.