Background: We examined secular trends in leisure-time physical activities (LTPA) in health-conscious men (n = 1359) from 1958 to 1998 and in women (n = 839) from 1978 to 1998, who were participants of the Baltimore Longitudinal Study of Aging (BLSA).
Methods: LTPA was the self-reported time spent performing 97 activities, and was converted to metabolic equivalent of oxygen uptake (MET) minutes per day. Evaluations of LTPA were averaged for each decade. The prevalence of a sedentary lifestyle in each decade was assessed based on compliance with widely publicized recommendations for participation in physical activity. All analyses were adjusted for age, education, and race differences across decades.
Results: Median high-intensity LTPA, defined as activities >/=6 METs, increased from 30 to 80 MET min/day from the 1960s to the 1990s for men (P < 0.01) but did not change between the 1970s and the 1990s in women. Moderate-intensity LTPA, defined as 4-5.9 METs, did not change significantly over these periods in either sex. The percentage of sedentary men, defined as those performing <40 MET min/day of high-intensity LTPA, declined across the four decades, whereas for women it did not change significantly.
Conclusions: In a health-conscious sample across a broad age range, national recommendations appear to have made modest progress in decreasing the proportion of sedentary adults.