Is Moderate Intensity Exercise the Real 'Best Way' to Prevent Diabetes?
If you have prediabetes, the standard advice to avoid getting diabetes is to do three things at once: cut calories, eat a low-fat diet, and get exercise. But a recent study shows that it makes more sense to focus on exercise alone.
Ever since 2002, when researchers published the results of the Diabetes Prevention Program, we have known that intensive lifestyle changes are the best way to avoid diabetes. That program aimed at reducing body weight by seven percent, eating a low-fat diet, and increasing physical activity to at least 150 minutes per week of moderate exercise, such as walking or biking.
The program, a large landmark trial, concluded that when following this strategy, the chance that a person will get diabetes decreases by 58 percent. The next best choice, taking the diabetes drug called metformin, reduces the chance of getting this chronic condition by 31 percent.
Prediabetes is still increasing
On the whole, however, the three-pronged strategy doesn't appear to be working well. The proportion of adult Americans who had prediabetes increased from 32 percent in 2002 to 38 percent in 2010, according to the 1999 - 2010 National Health and Nutrition Examination Surveys.
A July 2015 study suggests that a better approach for many people who have prediabetes might be to to focus on getting a high amount of moderate exercise. The peer-reviewed medical journal Diabetologia, which is the official journal of the European Association for the Study of Diabetes, published the study by researchers at the Duke University Medical Center in Durham, North Carolina.
The findings are the result of a randomized, six-month study of 150 participants with prediabetes. The researchers randomized them into four groups. The first group followed an intervention modeled after the Diabetes Prevention Program. The other three groups received exercise only, using different amounts and intensities: a low amount at a moderate intensity, equivalent to walking briskly for seven and half miles per week; a high amount at a moderate intensity, equivalent to walking briskly for 11.5 miles per week; and a high amount at a vigorous intensity, equivalent to jogging for 11.5 miles per week.
How the four groups fared
Not surprisingly, the people who were able to follow the intervention modeled after the Diabetes Prevention Program got the greatest benefit. They averaged a nine percent improvement in their oral glucose tolerance.
But the people in the group that followed a moderate intensity program of walking briskly for 11.5 miles each week came in a close second. They had an average seven percent improvement in oral glucose tolerance.
The group that walked seven and a half miles averaged a five percent improvement. Surprisingly, the vigorous intensity group -- the joggers -- had the least success. They averaged only a two percent improvement.
Why moderate exercise works better
A likely key to the superiority of moderate intensity exercise to that of high intensity exercise is that moderation tends to burn more fat than glucose, while the more intense exercise has the opposite effect, William Kraus, MD, the study’s lead author, said. He believes that one benefit of moderate intensity exercise is that it burns off fat in the muscles, which is important because the muscles are the major place where we store glucose after a meal.
“Our study found that with high intensity exercise compared to moderate intensity exercise -- the equivalent of jogging versus brisk walking -- the brisk walking was superior to the jogging in improving metabolic health in individuals at risk for diabetes, Dr. Kraus said. “The gold standard of lifestyle counseling is diet, weight loss, and exercise. The patient is overwhelmed by three activities at one time. They can focus just on exercise. This can really help them to get on the right path to improving their health.”
You may have heard that the best exercise is the one that you will do. Likewise, the best strategy for you to conquer prediabetes is the one that you will follow. Instead of trying to juggle multiple demands, this strategy is to focus on getting the exercise that you need.
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David Mendosa is a journalist who learned in 1994 that he has Type 2 diabetes, which he now writes about exclusively. He has written thousands of diabetes articles, two books about it, created one of the first diabetes websites, and publishes the monthly newsletter, “Diabetes Update.” His very low-carbohydrate diet, current A1C level of 5.1, and BMI of 19.8 keeps his diabetes in remission without any drugs.