Twenty-year trends in physical activity among Canadian adults.

OBJECTIVE: Physical inactivity is associated with increased risk of mortality and chronic diseases, yet trend information is lacking in most countries. This investigation examines physical activity levels of Canadian adults aged 18 years and older. METHODS: Data were collected in six national surveys between 1981 and 2000. Sample sizes ranged from 2,500 to 18,000. Prevalences were tested using Chi-square and Student's t-tests. Socio-demographic correlates were examined using odds ratios adjusted for age, sex, education and income. RESULTS: Physical activity increased in the 1980s and 1990s among men and women and for all age, education and income groups (p<0.01). Although education differentials narrowed over the period, age differentials widened and income differentials emerged. DISCUSSION: The positive trend in Canada is consistent with Finland, but contrary to recent trends for Australia, England and the United States. Despite increases, sedentary living remains a public health issue particularly among women, older adults and lower income groups.