Posted on 9 August 2022
Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.
Why is this research important: Type II diabetes mellitus is an increasingly common problem throughout the world, and this is in large part due to our increasingly sedentary lifestyles. Many people remain sitting in front of a desk for most of their working day. Type II diabetes mellitus is a chronic condition in which cells don’t respond properly to insulin, a hormone that controls blood sugar. This results in elevated blood sugar levels, which can cause serious damage if it is not kept under control through medication. Studies have shown that exercise can significantly improve the body’s responsiveness to insulin, lowering blood sugar and thereby protecting against diabetes. Furthermore, it seems that even very small amounts of exercise can still have a significant impact on blood sugar control.
What did the researchers do: In this study, researchers recruited 25 middle-aged men who were deemed physically inactive, but didn’t have any known metabolic condition such as diabetes. They were then randomly assigned to one of three groups. All participants spent 7 hours sitting down. One group spent the full 7 hours sitting down without interruption, one group spent 2 minutes standing every 20 minutes, and the other group took a two minute light-intensity walk every 20 minutes.
At the start of the test and again after 3 hours, participants consumed a fixed amount of glucose (sugar), and researchers measured their blood glucose and insulin levels throughout the test.
This entire experiment was repeated twice more, with the participants swapping groups each time.
Key takeaway(s) from this research: The Matsuda index, which is a measure of responsiveness to insulin based on insulin and glucose levels, was 16% higher in the walking group compared to the other two groups. Researchers also found that their blood sugar was better controlled following the glucose meals, and the total amount of insulin released over the course of the test was 21% lower for the walking group than for the other groups (this is a good thing – less insulin was needed to keep their blood sugar normal). There was no significant difference in either of these measurements between the standing group and the sit only group.
This would suggest that even very brief bouts of walking throughout the day can have a significant beneficial effect on blood sugar control, but standing doesn’t have any effect, at least not in short bouts. Previous studies do suggest that standing for longer periods does lower blood sugar significantly, so don’t throw away your standing desk just yet. You might want to invest in a treadmill to go with it, though.
Intermittent walking, but not standing, improves postprandial insulin and glucose relative to sustained sitting: A randomised cross-over study in inactive middle-aged men: https://doi.org/10.1016/j.jsams.2016.08.012