What if you could walk – not run – to control glucose levels and prevent pre-diabetes from progressing into the full version of the disease? According to researchers at Duke Health, taking brisk walks on a regular basis may be more effective at improving glucose control compare to vigorous jogging.
The Duke University researchers studied the effects of various types of exercise on 150 participants with pre-diabetes, over a six-month period. The results of the study – published in the journal, Diabetologia – was based on the assessment of patients with higher-than-normal fasting glucose levels.
All study volunteers were randomly assigned to one of four groups. The first group received an intervention based on the Diabetes Prevention Program (DPP), requiring study participants to eat fewer calories, adopt a low-fat diet and exercise regularly. Designed to help those with pre-diabetes reduce their body weight by seven percent over six months, the moderately-intense exercise was equal to approximately 7.5 miles of walking at a brisk pace each week.
The other three study groups featured exercise-based interventions only. Group two performed a low amount of moderate-intensity exercise (equal to 7.5 miles of brisk walking per week). Group three participated in a high level of moderate-intensity exercise (equal to 11.5 miles of brisk walking per week), while the fourth group completed a high amount of vigorously-intense exercise (equal to 11.5 miles of jogging per week).
“We know the benefits of lifestyle changes from the DPP, but it is difficult to get patients to do even one behavior, not to mention three,” said Dr. William Kraus, the study’s lead author and professor of medicine in the Division of Cardiology at Duke University School of Medicine. “We wanted to know how much of the effect of the DPP could be accomplished with exercise alone. And which intensity of exercise is better for controlling metabolism in individuals at risk for diabetes.”
Participants in group one showed the greatest progress, with an average nine percent improvement in tolerance to oral glucose. Volunteers performing moderate-intensity exercise equivalent to 11.5 miles, showed a seven percent improvement in glucose tolerance, while those performing moderately-intense exercise less-often showed just a five percent improvement. Interestingly, the group which participated in high-intensity exercise experienced the lowest improvement in glucose tolerance, at an average of two percent.
“Another way to say it is that a high amount of moderate-intensity exercise alone provided nearly the same benefit on glucose tolerance that we see in the gold standard of fat and calorie restriction along with exercise,” said Dr. Chris Slentz, assistant professor of medicine in the Division of Cardiology at Duke and a co-author on the study. According to the researchers, the results could be a reflection of how different intensities of exercise affect the body’s functions.
“High-intensity exercise tends to burn glucose more than fat, while moderate-intensity exercise tends to burn fat more than glucose,” said Kraus. “We believe that one benefit of moderate-intensity exercise is that it burns off fat in the muscles, which relieves the block of glucose uptake by the muscles. That’s important because muscle is the major place to store glucose after a meal.”
A diabetes outcome study could be the only way to confirm the link between moderately-intense exercise and management of pre-diabetes. However, the results of this study suggest that pre-diabetic patients may improve their outcomes by incorporating manageable low-intensity exercise into their day.
“When faced with the decision of trying to do weight loss, diet, and exercise versus exercise alone, the study indicates you can achieve nearly 80 percent of the effect of doing all three with just a high amount of moderate-intensity exercise,” said Kraus. “I was heartened by the fact that I found out that I can give patients one message and they can get nearly the same effect as when required to exercise, diet and lose weight all at the same time.”