The combination of moderate aerobic exercise and resistance training offers the best results as a strategy to lower the risk of diabetes while increasing mobility and functional capacity in obese older adults, a new study says.

The work, by researchers from Queen's University in Kingston, showed seniors who followed the exercise regime while eating a healthy diet saw significant improvements in their ability to function – and their bodies' ability to process sugars.

The combination of aerobic and resistance exercise was more effective than either form of exercise on its own.

"So if you looked at the two again and said `OK, what's my biggest bang for the buck? What's optimal?' then the dual strategy – 150 minutes of combined (per week) versus 150 minutes of only aerobic was optimal," senior author Robert Ross said from Mexico, where he was travelling for work.

The study, which was funded by the Canadian Institutes for Health Research, will be published tomorrow in the journal Archives of Internal Medicine.

It had been assumed that a combination of aerobic exercise and resistance training would be the best approach for reducing the risk of chronic disease and disability in aging adults struggling with obesity. This study, Ross said, shows that thinking was correct.

He and his co-authors studied a group of 136 sedentary and abdominally obese men and women aged 65 and older, assigning them to one of four groups. All were followed for six months.

One group did no additional exercise. One did resistance exercises for 20 minutes three times a week while another did aerobic exercise – walking on a treadmill – for 30 minutes five times a week. The fourth performed 30 minutes of aerobic activity three times a week and 60 minutes weekly of resistance training.

While the combined exercise group had the best results, those who did only aerobic activity also saw significant improvements in their fitness and their bodies' ability to process sugars – key to avoiding the development of Type 2 diabetes.

None of the groups lost a significant amount of weight, but the more strenuous exercisers did lose belly fat, the most dangerous form of fat.

Ross said the findings should serve as "a road map" for older adults trying to stay healthy.

"The optimal strategy is the combination of aerobic walking type exercise and resistance exercise, performed as prescribed," he said. "Throw that bathroom scale if they want out the door. I'm not concerned with that."