The longitudinal exercise trend among older Swedes aged 53-84 years - a 16-year follow-up study

Background: Many older adults are physically inactive and inactivity increases with age. This knowledge comes from cross-sectional studies. Cross-sectional studies may miss important trajectories within the older adults as a result of retirements, and poor health impact of promotional efforts. The aim of this study was to analyse, longitudinally, the annual effects of age group and birth cohort on self-reported regular exercise in the Swedish population aged 53-84 years during a 16-year period, for each sex separately. Methods: A random sample of non-institutionalized persons was interviewed three times from 1988 to 2004 by professional interviewers. In addition to three time-related variables - year of interview, age at the time of the interview, and year of birth - we included the following explanatory variables in the analyses: educational level, body mass index, smoking, and self-reported health status. The data were analysed by a mixed model with a random intercept. Results: The total prevalence of self-reported regular exercise increased between 1988/ 89 and 2004/ 05 among both men and women, from 27.1 to 43.1% and from 21.1 to 41.1%, respectively. There was a mean annual change in all age-groups in exercise of between 0.76 and 1.24% among men and between 0.86 and 1.38% among women. Low prevalence of self-reported regular exercise was associated with low educational level, obesity, smoking, and poor self-reported health, although those with poor self-reported health the greatest increase of physical activity. Conclusions: There was a steady, albeit inadequate, increase in self-reported regular exercise in older adults between 1988 and 2004. Physical activity promotion in older adults should be of high priority for both primary and secondary prevention of diseases, especially among groups with known risk factors for low levels of exercise.