Physical activity

Physical activity has benefits for all people with or without diabetes. They include:

  • Helping you feel better about yourself
  • Helping to keep blood glucose in the target range
  • Increasing insulin sensitivity (the insulin produced is better able to work)
  • Helping you to lose weight and maintain a healthy weight
  • Helping you to deal with stress
  • Keeping joints more mobile and less stiff
  • Keeping bones healthy and strong
  • Reducing the risks for stroke and heart attack
  • Lowering blood pressure
  • Improving circulation
  • Reducing feelings of depression and anxiety

Types of physical activity can be classified into two groups: aerobic and anaerobic.

Aerobic uses large muscle groups that require oxygen for sustained periods. For people who are fit this might be going for a run; for people who are not fit it might be walking 100 paces.

Resistance (anaerobic) uses large muscles that do not require oxygen for short periods of exercise.

Most guidelines for people with diabetes recommend physical activity (including aerobic and/or resistance training) several times a week.

People with type 2 diabetes should accumulate 30-45 minutes a day 3-5 days a week, or 150 minutes a week of aerobic exercise.

Aerobic exercise, such as walking, jogging, swimming, skipping, bike riding, should be intense enough to increase the pulse rate and the respiration rate. Brisk walking is probably the most common form of aerobic exercise.

People with diabetes should be encouraged to perform resistance exercise 3 times a week. Resistance training does not necessarily require expensive equipment. Weights used can be as simple as a can of soup or a packet of grain. It is better to use repetitive light weights than heavy weights.

The type, frequency, duration and intensity of exercise should be adjusted according to individual fitness levels.

People who have not been recently physically active and are intending to start exercising should see a health care professional in order to identify the risks associated with physical activity and how to manage these risks.

For people with type 1 diabetes there are risks associated with unplanned physical activity. The primary one is hypoglycaemia. Therefore physical activity should be planned for and changes made to carbohydrate intake and/or insulin dose.

Before starting exercise, people with type 1 diabetes should:

  • Drink adequate amounts of water.
  • Ensure that footwear is appropriate to protect feet from injury and keep them dry.
  • Wear some form of diabetes identification, such as a bracelet or necklace.
  • Ensure exercise partners know how to recognize and treat low blood glucose (hypoglycaemia).
  • Warm-up for 5-10 minutes.
  • Test blood glucose prior to activity.
  • If blood glucose is more than 252mg/dl (14mmol/L), do not exercise.
  • Check for ketones in case of type 1 diabetes.
  • If blood glucose is less than 108mg/dl (6mmol/L), eat 15 grams of carbohydrate.
  • Have a glucose source readily available throughout the activity.

Special precautions need to be taken when treating hypoglycaemia would be difficult, such as when scuba diving, hang gliding or rock climbing.

People with type 1 diabetes need to monitor their blood glucose frequently after exercising because of the risk of delayed hypoglycaemia. They may also need to reduce insulin or increase their bedtime snack to prevent a hypoglycaemic event overnight.

The risk of hypoglycaemia is reduced in type 2 diabetes and unlikely in people who manage their condition through lifestyle measures alone. People with type 2 diabetes on anti-diabetic medications or insulin therapy may need to adjust their medication prior to prolonged and excessive exercise and should always carry a source of glucose.