(THE CONVERSATION) – The Research Brief is a brief overview of interesting academic work.
The big idea
To reduce the harmful health effects of sitting, take a five-minute light walk every half hour. That’s the key finding of a new study my colleagues and I published in the journal Medicine & Science in Sports & Exercise.
We asked 11 middle-aged and older healthy adults to sit in our lab for eight hours, which represents a standard workday, over the course of five separate days. On one of those days, participants sat for the full eight hours with only short breaks to use the bathroom. On the other days, we tested a number of different strategies for breaking up a person’s sitting with light walking. For example, on one day, participants walked for one minute every half hour. Another day, they walked for five minutes every hour.
Our goal was to find the least amount of walking that could be done to offset the detrimental health effects of sitting. Specifically, we measured changes in blood sugar levels and blood pressure, two important risk factors for heart disease.
We found that five minutes of light walking every half hour was the only strategy that substantially reduced blood sugar levels compared to sitting all day. Notably, five minutes of walking every half hour reduced the blood sugar spike after eating by nearly 60 percent.
That strategy also reduced blood pressure by four to five points compared to sitting all day. But shorter, less frequent walks also improved blood pressure. Just one minute of light walking every hour reduced blood pressure by five points.
In addition to the physical health benefits, there have also been mental health benefits from walking breaks. Throughout the study, we asked participants to rate their mental state using a questionnaire. We found that compared to sitting all day, five minutes of light walking every half hour reduced feelings of fatigue, put participants in a better mood, and helped them feel more energetic. We also found that just one walk every hour was enough to improve mood and reduce feelings of fatigue.
People who sit for hours develop chronic diseases including diabetes, heart disease, dementia and several types of cancer at much higher rates than people who move around during the day. A sedentary lifestyle also puts people at a much greater risk of premature death. But daily exercise alone may not reverse the detrimental health effects of sitting.
Due to advances in technology, the amount of time adults in industrialized countries like the United States spend sitting has been steadily increasing for decades. Many adults now spend most of the day sitting. This problem has only gotten worse since the onset of the COVID-19 pandemic. With the migration to more remote work, people are less inclined to venture outside the home these days. So it is clear that strategies are needed to combat a growing 21st century public health problem.
Current guidelines recommend that adults should “sit less, move more”. But these recommendations don’t provide any specific advice or strategy for how often and for how long to move.
Our work provides a simple and cost-effective strategy: Take a five-minute brisk walk every half hour. If you have a job or lifestyle where you have to sit for extended periods, this behavior change could reduce the health risks of sitting.
Our study also offers clear guidance to employers on how to promote a healthier workplace. While it might seem counterintuitive, taking regular breaks to walk around can actually help workers be more productive than working non-stop.
What we don’t know yet
Our study mainly focused on taking regular breaks to walk at a light intensity. Some of the walking strategies, such as brisk walking for a minute every hour, didn’t lower blood sugar levels. We don’t know if more rigorous walking would have provided any health benefits at these doses.
We are currently testing over 25 different strategies to compensate for the health damage caused by prolonged sitting. Many adults have jobs, such as driving trucks or taxis, where they simply can’t walk every half hour. Finding alternative strategies that produce comparable results can provide the public with different options and ultimately allow people to choose the strategy that works best for them and their lifestyles.