Spending too much time sitting can harm heart health, even in active people, according to a study that associates more than 10 and a half hours of sedentary behavior a day with a higher risk of heart failure and cardiovascular death. This is the main conclusion of a study with 89,530 participants published in JACC, the journal of the American College of Cardiology, and presented at the 2024 scientific sessions of the American Heart Association.
They sent data from a triaxial wrist accelerometer that captured movement over seven days; the average daily sedentary time was 9.4 hours. After an average follow-up of eight years, 3,638 individuals (4.9%) developed atrial fibrillation, 1,854 (2.1%) heart failure, 1,610 (1.84%) heart attack, and 846 (0.94%) died.
"Spending more time sitting, reclining, or lying down during the day can be harmful to the heart," according to experts. Insufficient exercise is a known risk factor for cardiovascular disease. Current guidelines recommend more than 150 minutes of moderate to vigorous physical activity per week to promote heart health.
However, according to the study experts, exercise is only a small part of total daily activity, and current guidelines do not provide specific guidance on sedentary behavior, which represents a much larger part of daily activity. This research examined the amount of sedentary time during which the risk of cardiovascular disease is higher and explored how this behavior and physical activity jointly impact the odds of atrial fibrillation, heart failure, heart attack, and mortality.
Among the 89,530 study participants, the average age was 62 years, and 56.4% were women. For atrial fibrillation and heart attack, the risk increased steadily over time with no major changes. In the case of heart failure and cardiovascular mortality, the increase in risk was minimal until sedentary time exceeded 10.6 hours a day, at which point the risk increased significantly, showing a threshold effect.
In participants who met the recommended 150 minutes of moderate to vigorous physical activity or more, the effects of sedentary behavior on the risks of atrial fibrillation and heart attack were substantially reduced, but the effects on the increased risk of heart failure and mortality remained significant.
