Comparing physical activity routines in people with type 2 diabetes

This study investigated whether interrupting sitting with light-intensity walking could improve glucose levels and insulin resistance in people with type 2 diabetes (T2D) more than structured exercise. It determined that while both routines reduced glucose levels, only interrupting sitting reduced insulin resistance.

150 minutes of mild-to-high intensity exercise per week is recommended for the treatment and prevention of T2D. However, these guidelines are rarely followed. Thus, other forms of physical activity have been suggested.

Recent evidence suggests that longer periods of time spent sitting increases the risk of T2D. It has been suggested that interrupting sitting with small bouts of walking may be effective, and less demanding than structured exercise programs.

19 adults with T2D followed 3 different routines. During the 'sitting' routine they limited walking and standing to 1 hour per day each, and spent the rest of the day sitting or sleeping. During the 'exercise' routine 1 hour each day of sitting was replaced with supervised cycling. In the 'sit less' routine participants replaced roughly 5 hours of sitting each day with 2 hours of low-intensity walking and 3 hours of standing. They were told to break up periods of sitting every 30 minutes. Each routine was followed for 4 days. There was a 10 day break between routines. The order of routines was random for each participant. Diet was the same during each routine.

Physical activity was measured with an accelerometer (a device that measures changes . Glucose levels were measured for 24 hours on the 4th day of each routine. On the day after each routine finished, fasting blood glucose levels (levels after a period without food or drink) and insulin levels were measured. This was used to calculate insulin resistance and sensitivity.

The 'sit less' routine decreased glucose levels 36% compared to sitting. The 'exercise' and 'sit less' routines decreased glucose levels by a similar amount. Insulin resistance was reudced by the 'sit less' routine, but not the 'exercise' routine.

The study concluded that interrupting sitting with short bouts of light activity reduces glucose levels as much as structured exercise, and improves insulin resistance more than structured exercise.

This was a small study, including only 19 participants. Women were under-represented in the study and all participants were overweight or obese. Thus the results may not apply equally to all people with T2D.

Discuss different physical activity routines with your physician.