By Mary Macvean | May 8, 2014.
Here’s a new kind of before-meal snack: A little intense exercise might be a good plan for people trying to control their blood sugar.
Researchers call it “exercise snacking,” and say that a brief burst of intense exercise is more effective than a moderate daily 30-minute workout at reducing glucose concentrations in people who are insulin resistant.
Their work was published Thursday in the journal of the European Assn. for the Study of Diabetes.
“Sustained hyperglycemia following meals is an important feature of insulin resistance,” researcher Monique Francois, of the University of Otago, Dunedin, New Zealand, said in a statement. “Reducing these post-meal spikes is important for reducing the risk of developing Type 2 diabetes and its associated complications.”
The scientists recruited two women and seven men ages 18 to 55; they all had blood tests showing insulin resistance; none were taking diabetes or or heart medication. Their mean body mass index was 36, which is obese. Type 2 diabetes was detected in two of the people during the screening.
Type 2 diabetes and insulin resistance are increasing worldwide, and exercise and diet are inexpensive and effective ways to combat them, the researchers said. But, they added, fewer than 10% of Americans and 20% of British adults meet activity recommendations. Many people cite a lack of time as the reason they do not.
So these scientists tried a plan that even the busiest person could slip into the day. The study participants took part in three exercise programs. The meals and timing were controlled.
In one plan, the person did 30 minutes of moderate intensity exercise before dinner, walking up an incline. That means the heart rate was at 60% of its maximum.
In the second, the person did six one-minute bursts of incline walking at 90% of maximum heart rate, 30 minutes before a meal. And in the third, the person did six one-minute efforts, alternating resistance training and incline walking 30 minutes before meals.
In the second and third plans, blood sugar was reduced 17% three hours after the meal compared with not exercising before breakfast, and 13% compared with the daily half-hour workout. The effect at lunch was unclear, the researchers said.
Among physical activity advocates, such bursts of exercise are called High Intensity Interval Training. It has, the researchers said, been shown to be an efficient way to improve blood glucose control in people with Type 2 diabetes, and as a way to reduce risk factors for other chronic diseases.
The researchers noted that the 150 minutes a week of exercise routinely recommended leaves plenty of sedentary time over a day, and that inactivity can be harmful. Previous research, they said, has shown that frequent activity sessions can help with waist circumference, blood sugar control and other issues.
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