Exercise
Diabetes and Exercise
In order to stay healthy, everyone should do physical exercise. Everyone should be encouraged to take part in regular physical activities like bicycle riding to work, and people with diabetes are no exception to this. Regular physical exercise lowers cardiovascular risk factors like overweight, high blood pressure and high blood lipids. Lack of physical exercise results in increased insulin resistance, development of obesity/overweight, and deterioration in blood glucose control.
Exercise can be classified into two forms, anaerobic and aerobic. The anaerobic activities are characterized by higher intensities of muscular work (e.g.; sprinting, weight lifting, playing rugby, etc.) Anaerobic efforts lasts only a short time but it may increase the blood glucose level dramatically due to the release of the hormones, adrenaline and glucagon. This rise in blood glucose is usually transient, lasting 30-60 minutes and it can be followed by low blood sugar (hypoglycaemia) in the hours after finishing the exercise.
Aerobic exercise involves lower intensities of muscular work (e.g. swimming, rowing, cycling, brisk walking, etc.). Many aerobic activities include short burst of anaerobic activities e.g. football or basketball. The aerobic activities tend to lower blood glucose both during and after the exercise. That usually happens within the 20-60 minutes after the onset of the exercise.
How Do You Exercise If You Have Diabetes?
Ensure that your blood glucose level is at least greater than 6.5 mmol/L but less than 14.0 mmol/L before you start the exercise. If you blood glucose level is less than 5.5 mmol/L before you start your activity, take a small carbohydrate snack (about 15-30 grams ) to increase your blood glucose and reduce your risk of low blood glucose(hypoglycaemia).This is important if you anticipate that you will be exercising longer than 30 minutes. To be able to run quickly, your muscles need glucose. You will need approximately 10-20 grams of carbohydrates for every 30 minutes of exercise. It is advisable to avoid exercising a day after an episode of severe hypoglycaemia.
When your blood glucose level is above 14.0 mmol/L and there is raised ketones indicating lack of insulin delivery, exercise should be postponed while extra insulin is taken. Running to lower a high blood glucose in this situation is not a good idea and it might be dangerous. You can never replace insulin with exercise. If your blood glucose is higher than 14.0 mmol/L without ketones approximately 0.05 IU/kg body weight of short acting or preferably rapidly acting insulin and wait for 1-2 hours for it to have effect.