Background: The health benefits of physical activity are well established, but the overall amount of physical activity associated with cardiovascular and other health outcomes, and whether the relationships are similar in men and women and at different ages is still debated. This may be partly related to different methods for assessing physical activity. Most studies have focused on leisure time physical activity.
Methods: We examined the prospective relationship between usual physical activity, taking into account both leisure and work activity, using a simple, pragmatic, four-point rating scale validated against heart rate monitoring, and cardiovascular disease incidence and total mortality after an average 8 years follow-up in 22,191 community living men and women aged 45-79 years with no known cardiovascular disease or cancer at baseline.
Results: The relative risks (95% confidence interval) for all-cause mortality (1,553 deaths) for men and women who were moderately inactive, moderately active, and active compared with those who were inactive were 0.83 (0.73-0.95), 0.68 (0.58-0.80), and 0.68 (0.57-0.81), respectively, after adjusting for age, sex, systolic blood pressure, blood cholesterol, cigarette smoking, alcohol intake, diabetes, body mass index, and social class. The relationships were also consistent for cardiovascular disease incidence (3,079 events), in subgroups stratified by age, sex, body mass index, smoking status and social class, and after excluding deaths in the first 2 years. The combined scale was more consistently associated with mortality than the individual work and leisure time components separately.
Conclusions: When both work and leisure time physical activity patterns are taken into account, using a simple, pragmatic, validated questionnaire feasible for use in clinical and public health practice, even very moderate levels of usual physical activity are associated with significantly reduced risk of mortality and cardiovascular disease in men and women in the general population and potential population attributable impact of 14% for inactive compared with active levels. These findings may encourage efforts to increase physical activity levels not only in leisure time but also in usual daily working life.