Researchers at the Queen’s University, Kingsland, Ontario, Canada, and Columbia University, New York, conducted a randomized clinical trial involving 136 sedentary older adults who were abdominally obese, meaning they had a waist circumference of at least 40″ for men or 35″ for women. For 6 months, participants were randomly assigned to one of 4 groups:
1) resistance exercise (one set of nine exercises, 20 minutes three times per week),
2) aerobic exercise (30 minutes of moderate-intensity treadmill walking five times per week),
3) combined exercise (30 minutes of aerobic exercise three times per week plus 60 minutes of resistance training weekly), and
4) a control group that did not exercise.

After 6 months, insulin resistance improved in the aerobic and combined exercise groups as compared with the control group. In addition, all exercise groups improved their functional limitation compared with the control group. The combined exercise group showed greater improvement than the aerobic-only group. Cardiorespiratory [heart and lung] fitness increased in the aerobic and combined exercise groups but not in the resistance exercise group.

“Health care providers are encouraged to promote performance of resistance and aerobic exercise in older adults for simultaneous reduction of insulin resistance and functional limitations, established risk factors for disease and disability,” said the authors.

Insulin resistance often leads to diabetes.