The
President’s Council on Physical Fitnessand
Sports was created in 1956 to promote awareness of the health importance of
exercise and physical fitness (1).
The
International
Symposium on Physical Activity and Cardiovascular Health was held in Toronto
in 1966
(5).
The
National Health Interview Survey introduced questions on exercise and
physical activity in 1975 and shortly thereafter became one of the major
surveillance tools for monitoring changes in the prevalence of physical activity
among U.S. adults.
Selected
milestones
in physical activity research, promotion and surveillance over the past 50
years provide context for understanding the evolution of physical activity
measurement in the National Health Interview Survey.The
following surveys served as the foundation for the early work of the NHIS in
the study of physical activity:
In
the 1950s, the Tecumseh Community Health Study, a comprehensive health
study of residents of Tecumseh, Michigan, used a highly structured
questionnaire that asked an extensive set of questions about physical
activity including intensity, frequency and duration of activities
(expressed in terms of hours per week), averaged over one year (2),
(3).
In
the 1960s, a community-based study entitled “Health and Ways of Living,”
conducted in Alameda County, California, included questions on a limited
number of physical activities in a self-administered questionnaire (4).
The physical activity questions were introduced by a phrase indicating that
the respondent was being asked about things people do in their “free time”
--- the precursor to the widely used concept of “leisure-time physical
activity.” The Alameda Study questionnaire also included the question “Are
you more physically active or less active than most people your age?” ---which first appeared in the NHIS in 1975 and continued periodically
throughout the following 25 years.
In
the 1970s, the Minnesota Leisure Time Activity (LTA) questionnaire was
developed for use in a structured interview setting (6).
The Minnesota LTA questionnaire asked about participation in specific
physical activities or exercises during the last 12 months. For each
activity reported, respondents were asked to identify the month(s) in which
they engaged in the activity, the number of times per month, and the
duration per occasion.
Intensity codes were assigned for each activity, an approach adopted by the NHIS in the 1980s.