Type 2 diabetics can significantly lower their blood sugar — and lose body fat in the bargain — with an exercise program that combines aerobics and weight lifting, a new study reports.
While that regimen is already recommended for Type 2 diabetes, researchers say the study, published Nov. 24 in The Journal of the American Medical Association, offers some of the best evidence to date that a combined program offers greater benefits than aerobics or weight lifting alone, even if it does not increase total exercise time.
“We can now look at individuals with diabetes right in the face and tell them, ‘This is the best exercise prescription for you,’ ” said the paper’s lead author, Dr. Timothy S. Church, director of preventive medicine research at Pennington Biomedical Research Center at Louisiana State University.
Such a program consists of “about 100 minutes of higher-intensity aerobics a week, and then give yourself one to two days of resistance training for 15 to 20 minutes a day,” he said.
The study randomly divided 262 inactive Type 2 diabetics, average age 55.8, into four groups — 73 assigned to resistance training three days a week, 72 to aerobic exercise, 76 to the combination and 41 to a non-exercise comparison group. The study was notable in that almost half the participants were not white, and 63 percent were women.
After nine months of observed exercise, participants who did the combination training lowered their blood level of the glucose marker HbA1c to 7.3 percent from 7.7 percent, on average, a drop that corresponds to a significantly reduced risk of heart disease, Dr. Church said. The improvements in the other exercise groups were not significantly different from those in the non-exercise group.
Dr. Church said he was surprised but added that the findings made sense. “Diabetes is the failure to control the amount of sugar in your blood, and the biggest user of blood sugar is skeletal muscle,” he said. “The healthier your skeletal muscle, the more blood sugar it’s chewing up and taking out of the blood.”
Finnish researchers found that diet and exercise counseling resulted in a 58% reduction in diabetes risk among people who are prime candidates for developing the condition, which is associated with obesity and sedentary lifestyle.
The more lifestyle changes people make, the better. But achieving at least some changes is better than not trying at all. For example, weight loss does not appear to be an absolutely essential part of the equation, the report indicates.
Although even modest weight loss conferred a much lower risk of diabetes, those who participated in four hours of exercise per week--even if they did not achieve their weight loss goal--had a reduction in diabetes risk, the investigators found.
``It is likely that any type of physical activity--whether sports, household work, gardening or work-related physical activity--is similarly beneficial in preventing diabetes,'' according to lead author Dr. Jaakko Tuomilehto of the National Public Health Institute in Helsinki and colleagues.
The study participants included 522 middle-aged, overweight adults with impaired glucose tolerance--a harbinger of diabetes. The patients in the intervention group met with a nutritionist seven times in the first year and every three months afterward. They were given one-on-one counseling aimed at reducing weight, exercising more, eating less fatty foods and boosting intake of fiber-rich foods such as fruits, vegetables, oatmeal and bran cereal.
A second group, the ``control'' group, was given written information about the benefits of eating a healthier diet and getting more exercise, but did not participate in a specific program.
After 2 years, the men and women in the intervention group lost nearly 8 pounds on average, while those in the control group lost only about 2 pounds.
After 3 years, a total of 27 people (3% per year) in the intervention group and 59 people (6% per year) in the control group developed diabetes--a risk reduction of 58% for those in the treatment group, according to the report in the May 3rd issue of The New England Journal of Medicine.
Changing eating habits and increasing exercise may be daunting, but the study shows that even modest alterations in lifestyle have a clear benefit.
``It is commonly argued that it is difficult to change the lifestyle of obese and sedentary people, but such pessimism may not be justified,'' Tuomilehto and colleagues write.