After controlling for many variables, including age, body mass and alcohol intake, the researchers found that engaging in aerobic exercise for at least 150 minutes a week lowered the risk of developing the disease by 52 percent. Doing the same amount of weight training, meanwhile, was associated with a 34 percent lower risk, independent of any aerobic exercise. But doing both led to the greatest reduction in risk. Dr. Willett said the mechanism behind weight training’s beneficial effect on diabetes most likely stems from its effect on insulin receptors.
The full paper is avaiable on-line at http://archinte.jamanetwork.com/article.aspx?articleid=1307571