An eight-year cohort study has found a strong association between physical activity and healthy ageing in later life.
The study recruited a sample of older adults and followed them over time. They measured the participants’ levels of physical activity and health every two years.
Other studies have already shown an association between activity and exercise. However, this longitudinal method enabled the researchers to assess whether people’s health improved after doing more exercise.
The participants were adults born before 29th February 1952 who had been recruited to the English Longitudinal Study of Ageing. People with an existing health problem at baseline were excluded.
Participants were defined as “healthy ageing” only if they were free from major chronic disease, cognitive impairment, limitaton of physical function or mental health problems.
Three categories of activity level were used: “Inactive”, “Moderate activity” and “Vigorous activity”.
The researchers looked at the overall correlation between level of health and physical activity. They also looked at the impact on health when people moved between physical activity categories.
3,454 people were included in the analysis. At follow-up, 19.3% of the sample was defined as “healthy ageing”.
|Activity level||N||“Healthy ageing”|
People engaging in moderate or vigorous activity were more than twice as likely to be “healthy” as those who were inactive. After adjusting for other factors,
- the odds ratio (OR) for moderate activity was 2.67 (95% CI 1.95 to 3.64)
- the OR for vigorous activity was 3.53 (95% CI 2.54 to 4.89)
Not all that surprising, you may think. But it was interesting that people who became active during the period of the study were also much healthier than people who remained inactive throughout:
- odd ratio 3.37 (1.67 to 6.78) for becoming active compared with remaining inactive.
- There was around a 70% response rate amongst the study participants. So these results may not show the complete picture.
- Participants’ activity levels were assessed using a self-report questionnaire that had not been validated at the time of the research. The authors comment that there was only “moderate” correlation between their outcome measure and objective measures of activity levels.
- The definitions of the three activity levels are not provided in this paper. The paper that reports these definitions is not available open access.
- People who are healthy are more likely to be able to exercise. It’s likely that there is a bidirectional effect that would tend to make us over-estimate the benefits of exercise in this type of study.
- However, there is evidence that taking up exercise preceded improvements in health.
- It’s not clear whether this analysis was planned in the original cohort study.
- Hamer M, Lavoie KL & Bacon SL. Taking up physical activity in later life and healthy ageing: the English longitudinal study of ageing. Br J Sports Med 2013; published online doi:10.1136/bjsports-2013-092993.
- Institute for Fiscal Studies. English Longitudinal Study of Ageing, 2013.