New York: 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 that my colleagues and I published in the journal Medicine & Science in Sports & Exercise.
We asked 11 healthy middle-aged and older adults to sit in our lab for eight hours representing a standard workday over the course of five separate days. On one of those days, participants sat for the entire eight hours with only short breaks to use the bathroom. On the other days, we tested a number of different strategies to break up a person's sitting with light walking. For example, on one day, participants walked for one minute every half-hour. On another day, they walked for five minutes every hour. Our goal was to find the least amount of walking one could do to offset the harmful health effects of sitting.
In particular, we measured changes in blood sugar levels and blood pressure, two important risk factors for heart disease. We found that a five-minute light walk every half-hour was the only strategy that reduced blood sugar levels substantially compared with sitting all day. In particular, five-minute walks every half-hour reduced the blood sugar spike after eating by almost 60%. That strategy also reduced blood pressure by four to five points compared with sitting all day. But shorter and less frequent walks improved blood pressure too. Even just a one-minute light walk every hour reduced blood pressure by five points.
In addition to physical health benefits, there were also mental health benefits to the walking breaks. During the study, we asked participants to rate their mental state by using a questionnaire. We found that compared with sitting all day, a five-minute light walk every half-hour reduced feelings of fatigue, put participants in a better mood and helped them feel more energized. We also found that even walks just once every hour were enough to boost mood and reduce feelings of fatigue.
Why it matters:People who sit for hours on end develop chronic diseases including diabetes, heart disease, dementia and several types of cancer at much higher rates than people who move throughout their day. A sedentary lifestyle also puts people at a much greater risk of early death. But just exercising daily may not reverse the harmful health effects of sitting.