Sitting too long during the day can be harmful to your heart, even if you get enough exercise, experts warn.
Sitting, reclining or lying down for more than 10.5 hours during the day may increase your risk of dying from heart failure, heart attack or stroke – even if you get the recommended amount of exercise, a study suggests.
Researchers at Massachusetts General Hospital analyzed data from fitness trackers that recorded the movements of almost 90,000 Britons over seven days.
Overall, sedentary time averaged about 9.4 hours per day. About eight years later, the team then tracked the participants’ heart health.
Analysis found that the chance of dying from heart failure, heart attack or stroke during this period was minimal until a certain ‘threshold’ of sedentary time was reached.
They found that the risk of dying from these causes increased significantly in people who sat, leaned or lay down for more than 10.6 hours a day.
And this was also the case for participants who met the recommended 150 minutes of moderate to vigorous exercise per week.
Shaan Khurshid, co-senior author of the study, said: ‘Our findings support reducing sedentary time to reduce cardiovascular risk.
They found that the risk of dying from heart attacks, strokes and heart disease increased significantly in people who sat, reclined or lay down for more than 10.6 hours a day.
‘10.6 hours per day marked a potentially important threshold associated with higher heart failure and cardiovascular mortality.
‘Too much sitting or lying can be harmful to heart health, even for those who are active.’
The team said future public health guidance should emphasize the importance of reducing sedentary time, by advising people to avoid more than 10.6 hours a day.
The findings were published in the Journal of the American College of Cardiology (JACC) and presented at the American Heart Association’s 2024 Scientific Sessions.
In an accompanying commentary piece, Charles Eaton, director of Brown University’s department of family medicine, said people tend to overestimate how much exercise they do and underestimate how long they are sedentary.
He said replacing just 30 minutes of excessive sitting a day with any form of physical activity can lower heart health risks.
For example, adding moderate to vigorous activity reduces the risk of heart failure by 15 percent and the risk of death from a heart attack or stroke by 10 percent.
And even light activity, such as leisurely walking, reduced the risk of heart failure by 6 percent and death from heart attack or stroke by 9 percent.
Harlan Krumholz, editor-in-chief of JACC, said: ‘This study adds to the growing evidence of a strong link between sedentary behavior and cardiovascular health.
‘The findings strongly suggest that we need to get people moving to promote better health.’