Why Sitting Too Much Could Harm Your Heart—Even If You Exercise

Prolonged Sitting May Increase Heart Disease Risk, Even for Active People

Spending most of your day sitting could significantly raise your risk of heart disease—even if you exercise regularly, according to new research.

“Our findings stress the importance of minimizing prolonged sitting, regardless of your physical activity levels,” said Dr. Ezim Ajufo, lead author of the study and a cardiology fellow at Brigham and Women’s Hospital in Boston.

The Dangers of Sitting Too Long

While it’s widely understood that excessive sitting can harm your health, the exact risks and thresholds remain under study, explained Dr. Keith Diaz, a behavioral medicine expert at Columbia University Medical Center, who was not involved in the research.

This study stands out for its large sample size and robust methodology. Researchers analyzed data from nearly 90,000 participants who wore activity trackers for a week. They then compared sedentary time to instances of heart-related conditions, such as heart attacks, strokes, and heart failure, in subsequent years.

The results showed that more time spent sitting was linked to an increased risk of cardiovascular disease. The researchers even suggested a guideline: try not to sit for more than 10.6 hours a day.

“That’s not a strict limit, but it’s a good starting point for public health recommendations,” Ajufo noted.

Why Sitting is Harmful

The study, published in the Journal of the American College of Cardiology, does have limitations. It relied on data from the UK Biobank, a biomedical database that primarily includes participants of White European ancestry. As a result, its findings may not fully apply to more diverse populations, Ajufo said.

Additionally, the study is observational, meaning it identifies associations but doesn’t prove causation. Still, there’s a logical explanation for the findings, Diaz said.

Muscles play a crucial role in regulating blood sugar and fat levels. For muscles to function optimally, they need regular movement. Prolonged sitting deprives them of that stimulation.

“Taking movement breaks helps muscles do their job effectively, and it doesn’t require much effort,” Diaz explained.

Simple Ways to Add Movement to Your Day

For office workers and commuters, sitting for 10 hours or more can accumulate quickly. Fortunately, incorporating movement into your day can help mitigate these risks.

Standing desks might not be the best solution, Diaz noted. While standing is better than sitting, it still doesn’t engage your muscles the way movement does.

Instead, consider alternatives like treadmill or bike desks, or take walking meetings. You can also set reminders to stand and move every 30–60 minutes or between tasks.

Importantly, a single workout at the end of the day likely won’t undo the negative effects of prolonged sitting, Ajufo said.

“Sometimes we think we can offset unhealthy behaviors with exercise,” she added. “But moderate to vigorous physical activity, like running or brisk walking, isn’t enough to counteract the harms of extended sitting.”

The Value of Regular Exercise

That doesn’t mean you should give up on exercise. Physical activity remains essential for overall health.

“You’re still better off than someone who sits all day and doesn’t exercise,” Diaz emphasized.

Incorporating frequent movement throughout your day, alongside regular workouts, is the key to minimizing health risks and maximizing benefits.

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