In North America, more than 35 percent of the population becomes diabetic, and most cases of diabetes could be prevented with exercise. A high rise in blood sugar levels causes sugar to stick on the surface of cells. Once there, the sugar can never get off and is eventually converted to sorbitol which destroys the cell to causes all the side effects of diabetes such as heart attacks, strokes, arteriosclerosis, nerve damage and so forth (even in people who have not been diagnosed as diabetic). So anything that prevents frequent high rises in blood sugar helps to prevent cell damage.
This month, a study showed that exercise lowered high blood sugar levels in diabetics far more when done after eating dinner than before eating (Journal of the American Medical Directors Association, July 2009). Muscle contractions drive sugar into cells with little or no insulin. These people were out-of-shape diabetics who walked slowly and for only 20 minutes. Longer and more intense exercise lowers insulin and sugar levels even more and would be even more beneficial.
Another new study shows that you should exercise before you eat because it lowers blood sugar levels the next morning (Medicine and Science in Sports and Exercise, August 2009). Nine healthy postmenopausal women exercised two hours on a treadmill twice a day. Those who exercised an hour before meals had a much lower rise in blood sugar at 16 hours after eating, compared to those who exercised an hour after their meals. Humans must use their muscles to stay healthy.
Contracting muscles after eating helps to prevent the rise in blood sugar that follows meals, and exercising before eating helps to keep blood sugar levels low the next morning. Of course many people do not have the time to exercise both before and after meals, but you will benefit from exercising whenever you can because lowering blood sugar and blood fats helps to prolong life and prevent diseases such as diabetes.