Physical activity and exercise

Any physical activity can increase sensitivity to insulin and increase the rate of glucose uptake into muscles for fuel. This can then increase the risk of hypoglycaemia.

The advantage of an insulin pump is the ability to use the temporary basal rate (TBR) to reduce insulin levels before, during, and after any activity to help manage blood glucose (BG) and reduce the risk of hypoglycaemia.

Physical activities such as cleaning, shopping, gardening, and manual occupations can affect BG levels in the same way that exercise and sport can.

A good place to start is a 30–50% TBR reduction.  Always document your BG before during and after exercise and review for next time.

Depending on the duration and intensity of activity, BG levels can fall during, immediately after, or up to 24 hours after physical activity whilst your body is replacing glucose stores.

It is important to monitor the impact of either physical activity or exercise on your BG pattern so that you can make adjustments to your insulin and carbohydrate intake if required.

Even with reductions to TBR, you may also need to consider additional carbohydrates or if appropriate reduce mealtime insulin prior to exercise. Some safety guidelines to help you stay safe can be seen below.

Safety guidelines for exercise

• In some situations when there is not enough insulin on board your BG level can also increase and you may begin to produce ketones.

• Whenever blood glucose above 13 mmol/l you must check for ketones and if present do not exercise but follow sick day guidance.

• If you combine drinking alcohol, with activity you are at an increased risk of hypoglycaemia. To prevent this a greater reduction to TBR would be advised.

• As you are at an increased risk of hypoglycaemia, it is essential to ensure that you always carry treatment options.

• Some people will need to reduce their basal rates much more.

• Some people need to reduce their bolus insulin if exercising within 90–120 minutes of eating.

• Some physical activity will increase blood glucose levels.

Discuss your individual exercise plan with your diabetes healthcare professional.

Runsweet is a good resource to look at to help you manage physical activity and exercise whilst using your insulin pump.