Adding supervision and resistance training to an exercise programme will substantially improve type 2 diabetes patients' blood glucose control and cardiovascular risk profile compared to exercise counselling alone, new research shows.
"Our study has confirmed the importance of doing aerobic and resistance exercise," Dr Silvano Zanuso of the University of Padua in Italy, one of the study's authors, told.
Dr Zanuso and his colleagues report the findings in the Archives of Internal Medicine. They recruited 606 sedentary men and women with type 2 diabetes, all of whom were overweight or obese.
Participants received either exercise counselling every three months for a year or counselling plus 150 minutes per week of supervised aerobic and resistance exercise, also for a year. Counselling focused on encouraging people to increase their level of physical activity to at least 150 minutes of moderate-intensity exercise per week, as recommended by the American Diabetes Association.
Supervised exercise group
Total physical activity, which was around 0.75 metabolic equivalent hours per week for both groups at the study's outset, increased to 10.0 for the control group and 20.0 for the supervised exercise group.
Median attendance for the exercise sessions was 80.3%. There was a 0.42 point decrease in HbA1C levels in the supervised group (from 7.12% to 6.70%), compared to an insignificant drop of 0.13 in the counselling only group (7.15% to 7.02%).
The supervised exercise group also showed significantly greater changes in HOMA-IR, serum insulin, systolic and diastolic blood pressure, cholesterol levels, waist size, BMI and hs-CRP levels as well as their total and non-fatal coronary heart disease risk scores.
While none of the control-group participants stopped using insulin during the study, 13.5% of the supervised group did; 5.1% of the supervised exercisers and 2.6% of the control group participants reduced the number of oral diabetes drugs they used without starting insulin.
Training improves insulin sensitivity
Dr Zanuso said that it's likely that resistance training improves insulin sensitivity by boosting muscle strength. "The best benefits can be obtained by those patients that are active throughout the day, so they do physical activity, plus a couple of days there are some spikes of structured exercise."
Dr Ronald J. Sigal of the University of Calgary and Dr Glen P. Kenny of the University of Ottawa in Ontario point out that Dr Zanuso's study is the largest to date of exercise interventions in type 2 diabetes, "allowing greater statistical power to detect small but clinically significant changes in a variety of important outcomes."
"The combination of aerobic and resistance exercise is particularly beneficial for improving blood glucose control and multiple other cardiovascular risk factors in people with type 2 diabetes and should be strongly encouraged," Dr Sigal told.
He added, "Even with aerobic exercise, where you think supervision might not be so relevant, it actually does have an impact."(Reuters Health/ November 2010)
Insulin resistance and diabetes