Sitting at your desk all day without breaks could significantly increase your risk of heart disease- even if you exercise during your free time, according to new research. "Our findings highlight the importance of minimizing prolonged sitting, regardless of your level of physical activity," said Dr. Ezim Ajufo, the study's lead author and a cardiology fellow at Brigham and Women's Hospital in Boston.
While it's widely understood that excessive sitting can negatively impact health, more research is needed to determine the specific risks and guidelines for what constitutes too much sitting, noted Dr Keith Diaz, an associate professor of behavioural medicine at Columbia University Medical Center, who was not involved in the study.
This research stands out for its large sample size and robust methodology, Dr Diaz said. It analyzed data from 90,000 participants who wore accelerometers for a week, comparing their sedentary and active periods to subsequent diagnoses of conditions like heart attack, stroke, and heart failure. The findings, published in the Journal of the American College of Cardiology, reveal a clear link between prolonged sitting and an increased risk of cardiovascular disease.
The study also offered a preliminary guideline: limiting sitting to less than 10.6 hours per day. "This isn't a rigid threshold, but it's a reasonable starting point for public health recommendations," Ajufo said.
The data was drawn from the UK Biobank, a large biomedical research database that primarily includes White individuals of European ancestry, which may limit its applicability to more diverse populations, Ajufo noted. Moreover, as an observational study, it establishes associations but cannot definitively prove causation.
It's logical that extended periods of sitting could be harmful, Diaz explained, because muscles play a key role in regulating blood sugar and fat levels. To function optimally, they require movement. "Taking movement breaks gives your muscles the stimulation they need, and even small amounts can make a difference," he said.
For office workers who sit most of the day, including time spent commuting, those 10.6 hours can accumulate quickly. However, the solution may not be as simple as using a standing desk, Diaz cautioned, since standing still doesn't activate muscles the way movement does. Alternatives like treadmill or bike desks, or conducting walking meetings, can be more effective.
The key is to incorporate movement into your routine in practical ways, Diaz advised. He recommended standing or walking for a few minutes every 30 to 60 minutes or transitioning between tasks with short walks. Unfortunately, even an intense workout at the end of the day might not completely offset the risks of extended sitting, Ajufo warned.
"Sometimes we think we can completely make up for some of the unhealthy behaviours we have ... by going out and going for a run," she said. "What we can say from the findings is that moderate to vigorous physical activity -- so that's running, a brisk walk -- is not sufficient to neutralize the harmful effects of sitting."
However, researchers suggest that people should exercise and reap its benefits.
"You're still better off than the person who sat all day then didn't exercise," Dr Diaz said.
