The new analysis adds further evidence to the link between a sedentary lifestyle and the risk of disease and disability
Research suggests that older adults who increase the amount of moderate activity from less than three minutes a day to at least 14 minutes could cut their risk of stroke by more than 40%.
Being sedentary, whether sitting for long periods or otherwise not moving for lengthy bouts, has been linked to an increased risk of conditions from heart disease to obesity, with the World Health Organization stating that physical inactivity is a leading cause of disease and disability.
Writing in the journal Jama Network Open, researchers in the US reported how they analysed data collected through activity trackers worn for up to seven days by 7,607 participants within a period from 2009 to 2013.
“This study’s findings suggest that more time spent being physically active, especially at moderate intensities, and less time spent being sedentary, particularly in longer bouts, may help reduce the risk of stroke,” the authors said – although they warned that extrapolating specific results to individuals is more difficult.
The participants, who were on average just over 63 years old, were then followed up for an average of 7.4 years, during which time 286 of them had a stroke.
The team’s analysis revealed that the third of participants who managed at least 14 minutes a day had a 43% lower risk of stroke compared with the third of participants who managed less than 2.7 minutes of moderate to vigorous exercise a day. This was the case once factors such as age, sex, smoking status, alcohol consumption, heart conditions and amount of time spent sedentary was taken into account.
The analysis also suggested that four to five hours a day of light-intensity activity could lower stroke risk
“Of course, accumulating [that] would likely require some intentional effort as most older adults don’t achieve that much,” said Dr Steven Hooker, the first author of the study from San Diego State University.
Separately, the team added that the most inactive participants, who spent more than 13 out of the 16 recorded hours a day being sedentary, had a 44% higher risk of stroke than those who spent fewer than 11.8 hours in this state.
“These results support recent clinical and public health guidelines encouraging people to move more and sit less to maintain cardiovascular health,” the team said.
However, the study had limitations, including that only a maximum of seven days’ worth of data was collected for each participant.
Naveed Sattar, a professor of metabolic medicine at the University of Glasgow, who was not involved in the work, cautioned that the study may slightly overestimate the benefit of linking activity levels to stroke risk, in part as people with minor, often undetected, prior strokes may be able to walk less.
But, he said, exercise matters. “There is no doubt that being more active lessens excess body fat, and helps keep blood pressure at lower, healthier levels,” he said, adding that while any activity is good, moderate to vigorous exercise will offer more benefits for the time expended. “As both of these factors are strong risk factors for stroke, it follows that walking more and sitting less will protect the brain as well as the heart.”