Purpose: Few epidemiological studies have been conducted among middle-aged women on long-term total and specific physical activity (PA) trends. We studied in a cross-sectional setting the relationship of self-reported total daily PA with age and calendar time.
Methods: In a population-based cohort of 38,988 women aged 49-83 yr in central Sweden, information was collected on physical activity, such as work or occupation, household work, walking or bicycling, exercise, watching TV or reading, and other lifestyle factors through a self-administered questionnaire. Total and specific daily PA levels at ages 15, 30, and 50 yr were recalled retrospectively and measured as metabolic equivalents (MET·h·d−1).
Results: Total PA level linearly decreased with calendar time in all three age groups (slope for 5-yr change in calendar time among those 15 yr of age = −0.82; 95% confidence interval (CI), −0.86 to −0.78; among those 30 yr of age=−0.42; 95% CI, −0.45 to −0.38; and among those 50 yr of age = −0.62; 95% CI, −0.66 to −0.58). High-intensity activities such as walking or bicycling decreased by 0.21 MET·h·d−1 (95% CI, −0.22 to −0.20) every 5-calendar-year change among adolescents between the 1930s and 1960s. Total activity level decreased in all age groups by an average of approximately 3MET·h−1·d−1, corresponding to approximately 45 min of brisk walking.
Conclusions: Our results suggest that intervention efforts aimed at engaging in healthful amounts of physical activity are needed throughout the life cycle.