Effect is not maintained if the program continues in a home-based environment, without supervision. Dr. David Dunstan, of the International Diabetes Institute, presented the findings, at the 38th annual meeting of the European Association for the Study of Diabetes (EASD).
They studied 36 overweight, sedentary men and women with established type 2 diabetes (more than six months since diagnosis), for a period of 12 months. A body mass index (BMI) of 27 kg/m2 or higher defined "overweight", and the mean age was 67.4 years plus or minus 5.6 years.
During the first six months, participants followed a healthy eating plan designed to induce moderate weight loss, and were randomized to one of two groups: RT (n=19), in which subject were required to do three sets of eight repetitions at 75-85 percent of their one-repetition maximum three times/week; or light exercise training (LT, n=17), in which subjects were instructed to perform light exercise training (stretching) three times/week, in a supervised laboratory setting.
In Phase 2, participants received individualized instructions and equipment to continue either RT or LT in the home setting for a further six months.
At the end of supervised training, the reduction in HbA1c was greater in the RT group than in the LT group (RT -1.2 plus or minus 1 percent versus LT -0.4 plus or minus 0.8 percent, p<0.05). Furthermore, participation in RT resulted in an increase in lean mass (LM). Subjects in the LT group, on the other hand, experienced a slight decrease in LM (RT +0.5 plus or minus 1.1 kg versus LT -0.4 plus or minus 1.0 kg, p<0.05). RT also led to a greater increase in upper and lower body strength (p<0.05).
"The results show that a supervised, high-intensity resistance training program performed three days per week for six months is safe and well tolerated by older persons with type 2 diabetes, and is effective in improving glycemic control, muscle strength, and lean muscle mass.
However, the researchers also found that a six-month extension of home-based resistance training was not sufficient to maintain the benefits gained from supervised RT with respect to blood glucose control. At the completion of the home-based phase, HbA1c had returned to close to baseline levels. "It is likely that poor adherence to the exercise protocol during the home-based phase was the major contributor to these findings," Dr. Daly suggested.