The researchers report their work in a paper published online on Monday in the journal Circulation.
Lead author Mark Hamer, an associate professor of epidemiology and public health at University College London (UCL), told the press:
"These leisure-time activities represent moderate intensity exercise that is important to health."
"It is especially important for older people to be physically active because it contributes to successful aging," he added.
In their introduction, Hamer and colleagues say while a number of studies show physical activity protects the heart and cardiovascular system by influencing how the body deals with inflammation, there isn't enough evidence to confirm whether this might be true of the longer term.
So they looked at what happened to the link between inflammation and exercise in a very large group over ten years.
For their study, they examined data on 4,289 people of average age 49 from the Whitehall II study, which started in 1985 with more than 10,000 participating British civil servants to look the effects of lifestyle and occupation on heart health.
The participants had regularly filled in questionnaires that asked them about their lifestyle, including any physical activity, ranging from vigorous intensity such as demanding sports and workouts, to leisure and home pursuits such as brisk walking, cycling, gardening, housework and home maintenance.
They also gave blood samples, from which the researchers were able to assess levels of two important markers of inflammation: C-reactive protein (CRP) and interleukin-6 (IL-6).
The researchers set the baseline of their study at 1991, with a follow up of 11 years later, in 2002. Questionnaire responses and blood samples provided measures of physical activity and inflammatory markers at both these points.
The results showed that:
- 49% of the participants met the guideline amount of exercise recommended for heart health (a minimum of 2.5 hours per week of moderate to vigorous physical activity) throughout the study period.
- Participants who were physically active at baseline also had lower levels of the inflammatory markers.
- This difference remained stable over time.
- Compared to participants who rarely met the guideline level of recommended physical activity, the ones who consistently met it showed lower levels of both inflammatory markers at follow up (after adjusting for other potential influencing factors).
- Compared to participants who did not change their activity level over the study period, those who increased it, had lower levels of both inflammatory markers at follow up.
"Inflammatory markers are important because we have shown they are a key mechanism explaining the link between physical activity and the lower risk of heart disease."
"The people who benefited the most from this study were the ones that remained physically active," he added.
The researchers also found there was a rise in activity levels as participants entered retirement in the later stages of the follow up period.
At the end of the follow up, 83% of the participants were meeting the guideline level for physical activity.
"The percentage of exercising participants jumped quite a bit because they were entering their retirement during the last phase of the study, " said Hamer, adding this suggests "retirement seems to have a beneficial effect on physical activity levels".
He and his colleagues conclude:
"Regular physical activity is associated with lower markers of inflammation over 10 years of follow-up and thus may be important in preventing the pro- inflammatory state seen with ageing."
In a statement to the press on Tuesday, the British Heart Foundation said the study is good news for retirees, and give the example of 87-year Jack Oldman, who has led an active retirement and now plays table tennis with the BHF Hearty Lives project in Hull.
"I play at my club twice a week and still compete in my local league. If I couldn't play sport I don't know what I'd do," says Oldman, who also keeps active looking after his vegetable patch. He says his doctors have told him he has a great heart for his age.
Maureen Talbot, Senior Cardiac Nurse with BHF, said the study highlights the positive effect that changing exercise habits can have on the future health of your heart. It's never too late she says:
"Donning your gardening gloves, or picking up a paint brush, can still go a long way to help look after your heart health, as even gentle exercise can have a big impact on how well your heart ages."
But she also points out it's important "not to wait until you retire to get off the couch, as being active for life is a great way to keep your heart healthy".
Written by Catharine Paddock PhD