Sedentary behaviour can increase mortality risk, new study reveals

A sedentary lifestyle can have a serious impact on people’s health and has been linked to an increase in health problems such as obesity, diabetes, and hypertension. Now, a new study shows that sitting for long hours without breaks increases the risk of early death.

The study, published in the Journal of American Heart Association (JAHA), showed that older women who sat for 11.7 hours or more every day increased their risk of death by 30%, regardless of whether they exercised vigorously. The researchers suggest that people live longer when they get up and move around 20 minutes of sitting.

For the study, the researchers collected data from 6,489 women, aged 63 to 99, who were followed for eight years for mortality outcomes. Notably, this is the first study to apply a new and validated machine-learned algorithm, CHAP, to examine total sitting time and length of sitting bouts related to the risk of death. The CHAP algorithm uses machine-learning to accurately distinguish between standing and sitting

Sedentary behaviour can cause a reduction in muscle contractions, blood flow and glucose metabolism. “When you’re sitting, the blood flow throughout your body slows down, decreasing glucose uptake. Your muscles aren’t contracting as much, so anything that requires oxygen consumption to move the muscles diminishes, and your pulse rate is low,” study co-author Andrea LaCroix said in a press statement.

The researchers’ observations also showed that exercise cannot undo these negative impacts on health. According to the study, regardless of whether women engaged in low or high amounts of moderate-to-vigorous intensity physical activity, they showed the same heightened risk if they sat for long hours.

Co-author Steve Nguyen points out that not all sitting is the same. “There are cognitively stimulating activities that can result in sedentary behaviour, like sitting while studying a new language. Is sedentary behaviour in that context overall bad for a person? I think it’s hard to say,” he added in the statement.

Previous studies have also shown that a sedentary lifestyle can significantly impact people’s health. For instance, a June 2023 study, published in the journal Health and Quality of Life Outcomes, showed that a lack of physical activity among older adults is linked to lower quality of life.