One third of Americans will become diabetic because they eat too much and exercise too little. A study in Medicine and Science in Sports and Exercise (July 2006) shows that lifting weights can help to prevent and to treat diabetes.

Extra fat prevents your body from responding normally to insulin. Before insulin can do its job of driving sugar from the bloodstream into cells, it must first attach to little hooks on cell membranes called insulin receptors. Having extra fat in cells turns these receptors inward, making it far more difficult for insulin to attach to the receptors. This prevents insulin from doing its job of lowering blood sugar levels, even though your body is making plenty of insulin. That's why anything that makes you fat increases your risk for diabetes. Doctors can measure how cells respond to insulin with a sugar tolerance test.

In this study, adolescent boys were given a program of lifting heavy weights twice a week. After only 16 weeks, their muscles were larger and they lost fat. Sugar tolerance tests showed that the ability of their bodies to clear a load of sugar from their blood streams improved dramatically. This means that a regular weight lifting program deceases insulin resistence and thus reduces risk for becoming diabetic.