Age and temporal trends of total physical activity among Swedish women

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 chan-e 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% Cl, -0.45 to -0.38; and among those 50 yr of age = -0.62; 95% Cl, -0.66 to -0.58). High-intensity activities such as walking or bicycling decreased by 0.21 MET(.)h(.)d(-1) (95% Cl, -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 3 MET(.)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.