How Exercise Affects Glucose - The Importance Of Exercise: Diabetes A Plan For Living

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How exercise affects glucose

Exercise consumes nutrients, including glucose, and forces cells to draw on the glucose stored in muscle. Once this is depleted, the body turns to sugar in the blood for energy. This would cause a drop in the blood glucose level were it not for your liver, which under normal circumstances produces enough glucose to replenish the blood's supply. The demand for blood sugar can continue even when exercise has ended because muscles continue to remove glucose from the blood to restock their reserves.

For people with diabetes who use insulin, several factors can alter the usual balance between glucose supply and demand and cause hypoglycemia. If exercise occurs when there's too much insulin —for example, when insulin levels peak after a dose — the exercising muscle soaks in even more glucose than usual. And your liver's ability to make glucose is diminished. This combination can result in hypoglycemia. Finally, because blood flow increases during physical exertion, absorption of insulin from injection sites may be accelerated, especially if it's injected near the muscles being used. Certain medications for type 2 diabetes, especially sulfonylureas, can also cause blood sugar levels to drop too low during exercise.

So while exercise is encouraged, it can set the stage for low blood sugar, including severe hypoglycemia. To prevent this problem, you'll need to check your blood sugar levels and adjust your diet, insulin doses, and injection sites accordingly.

Last updated:	January 23, 2007