Exercise improves insulin sensitivity in older men

NEW YORK (Reuters Health) - Resistance training plus aerobic exercise is the best way to reduce insulin resistance and functional limitations in obese, older adults, according to a report in the Archives of Internal Medicine.

Resistance and aerobic exercise are thought to be important for lowering the risks of chronic disease and disability in older adults, lead author Dr. Robert Ross from Queen's University, Ontario, Canada, and colleagues explain. "However, the incremental effects of combined resistance and aerobic exercise compared with either modality alone on risk factors for disease and disability is generally unknown."

To investigate this topic, the researchers assessed insulin resistance and functional limitations in 136 sedentary, abdominally obese older adults who were randomly assigned to participate in exercise programs focusing on resistance training, aerobics, both, or neither (non-exercise control) for 6 months. The exercise interventions occurred at least three times per week with each session lasting 20 minutes or longer.

Compared with the controls, the combined exercise and aerobic groups experienced improvements in insulin resistance, whereas the resistance-only group did not. The improvements seen in combined exercise and aerobic groups were comparable.

As for functional limitations, benefits were seen with all three exercise interventions. Combined exercise was more effective than aerobic exercise, but not more than resistance exercise.

"Healthcare providers are encouraged to promote performance of resistance and aerobic exercise by older adults for simultaneous reduction of insulin resistance and functional limitations, established risk factors for disease and disability," the authors conclude.

SOURCE: Archives of Internal Medicine, January 26, 2009.