The benefits of regular exercise can be enjoyed by people with diabetes as much as anyone else. You can benefit from exercise in a number of ways:
If your diabetes is under good control, you should be able to do the same kind of physical activity as people without diabetes. Remember that this activity can affect your blood sugar. The extent of that effect depends on how long you exercise and how intensely.
The effect of exercise on blood sugar differs from person to person. It’s a good idea to learn how your body responds to different kinds of physical activities.
You need to have your diabetes well controlled before you start a new exercise plan. You should not exercise if your blood sugar is more than 14 mmol/l and you have ketones present in your urine. Your liver will produce sugar and ketones and your muscles will be unable to use sugar efficiently. In this case, increase your insulin dose and delay your exercise programme until your blood sugar is normal and your urine is ketone-free.
When you are physically active, your body burns sugar faster and can lower your blood sugar. To help prevent hypoglycaemia, test your blood sugar before the exercise session. You'll usually need to eat more before exercise, and maybe also during and after exercise. You may also need less insulin than usual but you can't exercise without taking some insulin.
Taking less insulin than usual before exercise may be a good idea. Often, this is only possible when you know how long and how heavy your exercise session is going to be.
When you do unplanned physical activity, it is important to eat an extra snack - such as pasta, fruit or bread - to avoid hypoglycaemia.
When you exercise for a long period of time, you will usually need to take less insulin and to eat extra food. Ask your diabetes care team how to do this.
There are no fixed rules, so you might try some different combinations to see what's best for you. If you're going to exercise heavily, you may need to lower your insulin dose by as much as 50%. You'll need extra water and food every 15 to 30 minutes. Juice or other sugary soft drinks work well.
Take some sugar, biscuits or juice with you when you exercise. Take your diabetes ID card too. It will tell people what to do if your blood sugar becomes so low that you need help.
If you are exercising with other people you should let them know you have diabetes. Tell them what the symptoms are when you have low blood sugar and what they should do if you suddenly need their help. Also tell them where you keep fast-acting sugar and your glucagon injection kit.
Make sure you use the right footwear for your particular type of exercise.
It’s a good idea to test your blood sugar after exercise. If it’s normal or low, you should eat some more food. Be aware that hypoglycaemia can develop several hours after a hard exercise session.
If you exercise late in the day, you should be particularly aware of hypoglycaemia during the night and eat an extra large snack at bedtime. You may also need to eat extra foods rich in carbohydrate, such as pasta, the following day.
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Last updated: August 2009