The study found that periodic interruptions over the course of the day were better for improving levels of insulin resistance than a single burst of exercise.
Interrupting long periods of sitting with short walks, standing, or light activity may hold the key to maintaining healthy blood glucose levels for those with type 2 diabetes (T2D), a new study from the Netherlands finds. In fact, these shorter, more frequent bursts of activity appear to help more than longer, less frequent periods of structured exercise.
The findings, reported December 1, 2016, in the journal Diabetologia may offer good news for practitioners involved in diabetes management: evidence shows that those with T2D have poor track records of sticking with rigorous exercise plans. But more frequent, less strenuous activities like walking may be less intimidating, giving those with T2D the chance to pursue attainable goals and improve their glycemic control.
As the authors from Maastricht University discussed, several recent studies have reported an association between the amount of sedentary time and increased risk of T2D, independent of the time spent exercising. Experiments suggest that interrupting long stretches of sitting—including time spent watching TV or using a computer at work—may work well in lowering glucose and insulin levels, both in overweight adults who don’t have T2D and in adults who have the disease. Activities can be as simple as finding time for a 20-minute walk, something that has been the focus of a Surgeon General’s public health campaign in the United States.
In the new study, investigators examined whether persons with T2D would respond differently under what they called “conditions of comparable energy expenditure.” In other words, would blood glucose or insulin sensitivity be any different if activity involved was a series of short walks vs an exercise class, assuming the calories burned were the same?
The study involved adults with T2D aged 40 to 75 years, and a BMI of at least 25 kg/m2, the level at which the CDC defines a person as being overweight. The upper BMI limit in the study was 35 kg/m2, the barrier for Class 2 obesity. People who were already exercising more than 2.5 hours a week, abusing alcohol or drugs, and had other disease or certain pharmaceutical use (including insulin) were excluded.
The study was a randomized crossover design. Patients did one of the following: 1) mostly sitting with 4415 steps; 2) 4823 steps per day and replaced 1.1 hours of sitting with moderate- to vigorous-intensity cycling; or 3) taking 17,502 steps per day with 4.7 hours of setting.
The incremental area under the curve for 24-hour glucose was significantly lower during the intervention with frequent breaks and 17,000-plus steps than in mostly sitting. Participants who mostly did steps did about as well on the glucose measure as those who engaged in the cycling, but the cycling failed to improve insulin resistance as measured by the HOMA2-IR (homeostatic model assessment for insulin resistance).
“Our results suggest that breaking sitting with standing and light-intensity walking may be an alternative to structured exercise to promote glycemic control in patients with type 2 diabetes,” the authors wrote.
Duvivier BM, Schaper NC, Hesselink MK, et al. Breaking sitting with light activities vs. structured exercise: a randomized crossover study demonstrating benefits for glycaemic control and insulin sensitivity in type 2 diabetes [published online December 1, 2016]. Diabetologia. 2016; DOI: 10.1007/s00125-016-4161-7.