Exercise is a powerful weapon against high blood glucose levels. Your blood glucose can stay lower for hours, even a day or more, after you exercise. Why? Being active makes your body work harder. When your body works harder, it needs more energy. To get that energy, your body starts using more of the glucose in your blood. And your blood glucose goes down. The more active you are, the more glucose your body uses.

Of course, any time your blood glucose goes down quickly, you risk hypoglycemia. That's why people with diabetes need to plan their activity carefully. You don't want to run around on an empty stomach just as your insulin reaches its peak. So try to plan those pick-up basketball games for after lunch or a snack, not before. If you decide to ride bikes with your friends at the last minute, check your blood glucose first. Have an extra snack if it's a little low. And always bring some glucose tablets and a snack with you for those unexpected lows.

Even though exercise usually lowers blood glucose, it's not a good idea to be active when you have really high blood glucose levels. High blood glucose can be a sign that you don't have enough insulin in your body. When that happens, your body starts producing ketones. Ketones are like poison; they can make you sick. Too much activity when you have high blood glucose can speed up ketone production, which can be dangerous. If your blood glucose is over 240 mg/dl (or whatever level your doctor tells you), check for ketones. If you have moderate or high levels, don't exercise. Instead, treat your ketones and check again. Wait until your ketone level goes down before you go outside for a game.

If you exercise extra hard or for a long time (like during a soccer game), you may want to take a short break and check your blood glucose. If it looks low, eat a snack. That'll give you the energy you need to keep going!

If you are really active, you'll learn how different types of exercise affect you. Then you'll know when to eat a snack or check your blood glucose. If you're just starting to be more active, you may have to check your blood glucose more often. Some people even end up lowering their insulin dose if they get plenty of daily activity (only if your doctor says so, though!)

People with diabetes do have to be a little more careful about when and how long they exercise. But don't let that keep you from the many benefits of being active. With just a little planning and preparation, you can have fun and feel great!