Interval Training Cuts Diabetes Blood Sugar
When it comes to our walking speed, moderation doesn't seem to be the best policy.
Those of us who have diabetes can manage our blood sugar levels better when we alternate between slow and fast walking, according to a new study. When we walk at a constant pace, we don’t get the reduced blood sugar benefit of our physical activity.
The conclusions of the study fly in the face of the usual recommendations that people with type 2 diabetes should avoid high-intensity exercise out of concern that we might get hurt and because we just aren’t likely to take this advice. Yet, the new study doesn’t show that we get any better blood sugar control unless we do interval training.
A team of nine researchers from Denmark’s University of Copenhagen, led by Dr. Thomas Solomon, just published the results in Diabetologia, the journal of the European Association for the Study of Diabetes. The study, “Mechanisms behind the superior effects of interval vs. continuous training on glycaemic control in individuals with type 2 diabetes: a randomised controlled trial,” was published online on August 7, 2014.
The researchers divided a group of 32 volunteers into three groups. One group alternated between brisk and slow walking for an hour. Another group walked at a constant moderate pace for an hour. The third groups were controls; they didn’t take daily walks.
The brisk pace was 70 percent of peak energy expenditure for three minutes. Then the interval training group switched to a slow pace of 40 percent of their peak energy expenditure for three minutes. This group repeated these six minutes 10 times.
The continuous pace of the second group was 55 percent peak energy expenditure for the entire hour. This works out to equivalent energy expenditure by the two groups.
Both the interval and continuous groups trained for an hour a day, five days a week. They kept at it for the four months of the study and perhaps longer.
The researchers thought ahead of time that the interval training group might get better blood glucose results. But they reported that they were surprised that the continuous training group didn’t improve their blood sugar levels over the course of the study. "It's this switch between the intensities that we think is critical here,” Professor Solomon says. Working hard and then resting hard is better than moderation.
Intervals of fast and slow walking do seem to help us a lot. But I think the jury is still out on how much exercise we need to get. The program of this study that calls for five hours of walking each week would be a demanding time commitment for many of us.
A couple of weeks ago, I reported here on another new study on physical activity, called “3 Reasons Why Some People with Diabetes Need to Run or Jog a BIT.” The study showed that running for just five or 10 minutes a day is good for our health.
I will be splitting the difference. I won’t be running because of previous injuries to my knees. But I will continue to walk, and now I will vary my speed.