People who take up fitness later in life are more likely to "age successfully" and stay healthy compared with those who remain couch potatoes, a large British study finds.

Researchers tracked the health of 3,454 people in England with an average age of 64 living in the community.  

Lifestyles Senior Swimmers

Engaging older adults in physical activity should be part of public health programs, researchers say. (Eric Risberg/Associated Press)

They defined healthy aging as being free of major chronic ailments such as heart disease or stroke, diabetes, emphysema, or Alzheimer's disease as well as having good mental health, preserving cognitive abilities, and being able to maintain social connections or activities over the eight years of followup.

"We demonstrate, for the first time, that participants who remained physically active through followup were most likely to age successfully," Simon Bacon of the Montreal Heart Institute at Concordia University and his co-authors concluded in the British journal of Sports Medicine.

"This study supports public health initiatives designed to engage older adults in physical activity, even those who are of advanced age."

Participants who took up activity were also more likely to remain healthy compared with those who continued to be inactive.

The findings show it's never too late to get fit and enjoy its benefits beyond the physical, Bacon said.

Patricia Clark of the Ontario-based Active Living Coalition for Older Adults said the group's research suggests barriers include access to transportation to get to a facility and fear of falling.

"We like to encourage [walking] for older adults because we ask them to simply walk like they're late for an appointment, so they know they're walking hard enough, that they are breathing a little faster," Clark said.

'The more you do, the more you can do'

Clark also suggested walking around an apartment or condo, and walking down stairs to get started.

"My philosophy: the more you do, the more you can do," agreed Marion Green, a 93-year-old former dancer from Toronto who continues to practise dancing, and use a treadmill and a stationary bike regularly, even after a hip replacement three years ago.

In the study, participants described the frequency and intensity of their physical activity in 2002-03, and then every two years until 2010-11. Some participants also had objective measurements of their physical activity.

The subjects also had their cognitive abilities and mental health assessed with a battery of tests, such as immediate and delayed recall of a list of 10 words and an objective test of walking speed.

Over the four years, nearly nine per cent became active, 70 per cent continued to get moderate or vigorous activity at least once a week, and nearly 12 per cent became inactive. The Public Health Agency of Canada lists walking quickly or bike riding as moderate-intensity aerobic activity and jogging or cross-country skiing as vigorous.

At eight years, participants who reported moderate activity were 3.1 times more likely to be healthy agers and those who took part in vigorous activity were 4.3 times more likely to be healthy agers compared with inactive participants.

The researchers acknowledged that a controlled trial is needed to test for cause-and-effect but said the long-term nature of the study of seniors living in the community offers better representation.

They took factors such as age, sex, smoking, alcohol intake, marital status and wealth into account in their statistical analysis. Those who had a disease when the study began were excluded.

The study was funded by National Institute on Aging in the U.S. and a consortium of U.K. government departments.

With files from CBC's Ron Charles and Melanie Glanz