We all know the importance of exercise (and probably think we should get more of it). But it’s especially valuable for people with diabetes — many studies have shown that, in addition to lessening anxiety and helping with weight control, exercise lowers blood sugar levels and raises the body’s sensitivity to insulin. Yet when it comes to exercise, scientists are continually learning more about how often, how much and when. Now a new study from researchers in Australia reports brief exercise stints done often might be the best option for people with diabetes.
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A main reason exercise is so beneficial for diabetes patients is because they are at higher risk for heart disease and reduced vascular function than people without diabetes. (Vascular function is an indication of blood flow, of the diameter and tone of blood vessels, and of the health of a patient’s arteries. Several methods have been developed to assess vascular function, which is considered a measure of heart disease risk and which is often impaired in people with diabetes.) And it’s no surprise that prolonged sitting is a risk factor in heart disease for everyone, not just people with diabetes, and in these pandemic times, many of us find ourselves sitting more than ever. According to the authors of the new study, because of “rapidly advancing technologies in workplaces, transportation and home entertainment, fewer opportunities exist for incidental activity, creating many contexts of daily life that are conducive to prolonged sitting.” The researchers also pointed out that achieving recommended exercise levels “continues to be challenging” in type 2 diabetes, “with numerous barriers to exercise reported.”
So how do we counter the effect of sitting too much? To find out, the research team, which was led by Frances C. Taylor of the Physical Activity Laboratory at the Baker Heart and Diabetes Institute in Melbourne, Australia, recruited 24 adults (ages 35 to 70, both male and female) who had had type 2 diabetes for more than three months and who were considered to be “inactive,”— that is, they were sitting for more than five hours a day and were not meeting recommended exercise guidelines. As far as the researchers were able to determine, this was the first study to analyze prolonged sitting and exercise periods in people with type 2 diabetes.
Each of the participants completed three “experimental conditions,” each lasting eight hours. In the first of the conditions, the subjects sat for eight hours without taking any exercise breaks (to achieve an absolute minimum of activity, they were taken on their bathroom breaks in a wheelchair). In the second, the subjects took breaks every half hour, during which they did exercises (squats, leg lifts and calf raises) for three minutes. In the third condition, they took six-minute exercise breaks once every hour. While experiencing the conditions and doing the exercises, the participants had various physical measurements evaluated, such as blood pressure, blood flow, and the diameter of the femoral artery, which supplies blood to the legs and feet.
The researchers determined that, compared to constant sitting, both exercise conditions resulted in improved blood vessel function. However, the improvement was significantly greater in the second condition, in which the exercise periods were shorter but more frequent. It appears, therefore, that how often a person with type 2 diabetes exercises is more important than how long the exercise lasts. As the researchers wrote, “Because blood vessel function deteriorates as type 2 diabetes progresses, it’s possible that more frequent interruptions to sitting are needed to preserve blood flow to the legs. Our findings suggest that more-frequent and shorter breaks may be more beneficial than longer, less-frequent breaks for improvement in vascular function….” They also said, “a high frequency break strategy may be suitable in sedentary workplaces.”
Want to learn more about exercising with diabetes? Read “Add Movement to Your Life,” “Picking the Right Activity to Meet Your Fitness Goals” and “Seven Ways to Have Fun Exercising.”