Total physical activity in relation to age, body mass, health and other factors in a cohort of Swedish men.

BACKGROUND: Despite a large public health interest in physical activity and its role in obesity and other chronic diseases, only a few reports to date have addressed total levels of physical activity in relation to age, body mass, health and other lifestyle factors.
OBJECTIVE: To investigate whether levels of total physical activity among men are associated with age, body mass, self-rated health and other lifestyle factors in a cross-sectional setting.
METHODS: In a population-based cohort of 33 466 men aged 45-79 y in central Sweden, we collected information about physical activity through a self-administered questionnaire. Level of total physical activity was assessed quantitatively based on six questions on different activities: work/occupation, housework, walking/bicycling, exercise, inactive leisure time and sleeping. The physical activity levels were measured as metabolic equivalents, MET-h/day. The relation between age, body mass index, smoking, education, marital status and self-rated health, and total physical activity was studied in a cross-sectional analysis, using multivariate regression.
RESULTS: Total daily physical activity was decreasing systematically between age 45 and 79 (-4.1%, 95% CI -4.6, -3.6). Obese men reported -2.6% (95% CI -3.0, -2.1) lower physical activity than normal weight men. Those with high education had -7.0% (95%CI -7.3, -6.7) lower total physical activity than those with elementary school. Men with self-rated poor health had -11.3% (95%CI -12.1, -10.6) lower physical activity than those reporting very good health. The cross-sectionally observed decrease with age was greatest among obese men (-8.7%), current smokers (-7.9%), low-educated men (-5.6%) and those with poor health (-9.8%); the subgroups with very good health reported almost the same level of total physical activity (-0.6%) for age 74-79 as for age 45-49.
CONCLUSIONS: The observed decreasing levels of total physical activity with age to large degree depend on health status and other factors. The characterization of subjects with low total physical activity levels is of importance for understanding observed worldwide trends in increasing prevalence of obesity. The better understanding of these phenomena might also facilitate a better planning of public health interventions with messages specifically adjusted for subgroups of population with lower physical activity.