Exercise and insulin sensitivity are said to be linked because studies suggest that exercise can improve insulin sensitivity in those at risk for type II diabetes. Type II diabetes and obesity often occur together because fat cells may use insulin less efficiently than other types of cells, so that people who are overweight or obese need more insulin to keep blood sugar levels normal. The pancreas normally produces insulin when it is healthy, but an obese person's pancreas may become overactive as it struggles to provide the additional insulin that person's body needs to control blood sugar levels. Over time, the pancreas may become stressed and stop functioning, requiring the use of synthetic insulin medications to control blood sugar levels. Exercise and insulin sensitivity may therefore be linked because exercise can help an obese person lose weight, therefore lowering his need for insulin and helping his body use insulin more efficiently.
Physicians typically refer to the state of lowered insulin sensitivity as insulin resistance. A diet low in carbohydrates and fats, and high in whole grains, fruits, and vegetables, can help improve insulin sensitivity to lower insulin resistance. Exercise and insulin sensitivity improvements can also go together. Some studies suggest that exercise alone can help improve insulin sensitivity and reduce the risk of type II diabetes.
Experts believe strenuous exercise isn't needed to help improve insulin sensitivity. Moderate exercise performed for half an hour, four or five times weekly has been shown by some studies to have the desired effect. Exercise and insulin sensitivity improvements typically occur together when the exercise is aerobic in nature, since aerobic exercises tend to burn more fat than anaerobic exercises, like strength training. Jogging, cycling, walking, or swimming are considered effective aerobic exercises for weight loss and insulin sensitivity improvement. Studies suggest that the ideal exercise regimen should raise the heart rate to about 70 percent of its potential maximum.
Most physicians think a healthy diet, exercise, and insulin sensitivity improvements can help to prevent type II diabetes in most patients. Dramatic weight loss is not believed to be necessary for increasing insulin sensitivity. A loss of just five percent of a person's total body weight is believed to reduce the risk of developing type II diabetes by more than half.