Insulin pump and sport
Sport is good for your health! Just a silly saying, you may say. But it is actually true: regular physical activity lowers blood sugar and improves insulin sensitivity in the long term, lowering the insulin demand. Diabetics also benefit from physical exercise, because exercise protects the cardiovascular system, reducing risk factors associated with cardiovascular disease. "Bad" fats, such as triglycerides and LDL cholesterol, go down; the "good" HDL cholesterol goes up, while blood pressure and heart rate go down as well. And sport, of course, helps you keep slim and in shape.
Yes: Sport and the insulin pump go together!
Anyone with type 1 diabetes, who is physically active and exercises, knows that certain situations can destabilise blood sugar levels – despite all the positive effects - because it lacks the fine-tuning of your own body.
Insulin pump therapy provides an excellent solution to this problem.
Someone with diabetes can engage in most kinds of sport. Because of the positive cardiovascular effects, endurance sports like running, Nordic walking, cycling, hiking, etc. are particularly suitable. Swimming is possible as well, although you may have to remove the insulin pump - follow the manufacturer's recommendations. Even martial arts and sports with body contact are allowed; but in this case you must remove the insulin pump because of the danger of the catheter getting caught and the inadvertent removal of the needle.
When to begin?
All insulin pumps have the option of reducing the basal rate by a percentage for a particular period of time. Depending on the type of insulin used, lowering the basal rate begins an hour prior to the use of insulin analogues or two hours prior to standard insulin.
Lowering the basal rate
The extent to which the basal rate needs to be lowered is dependent on the two remaining issues (duration of training and physical condition). The longer the duration of the physical activity, such as an all-day hike, the more you need to lower the basal rate. Anyone who is untrained, and has no experience in using the insulin pump during exercise, should seek advice from their diabetes team.
Individual requirements vary
There is no hard and fast rule for lowering the basal rate. The basic principle is: to avoid hypoglycaemia, you should begin with gentle training. It is easier to compensate for slightly higher values afterwards, than trying to find the energy to continue with your physical activity after suffering from hypoglycaemia during your first training session.
High values after sport
Anyone who already knows how to lower basal rates - and also manages to be successful at sports - may still occasionally experience a higher blood glucose level after exercising than before. A reason may be that the blood sugar was already too high in the first place, with an existing insulin deficiency. Before you start exercising you should thus always measure your blood sugar, and with raised values also check your blood for ketones, if ketones are present delay your activity to treat the high levels first.
Do not start with very low values
Measuring blood sugar before exercising is also essential to raising a low value. Before you begin exercising, your values should be between 8.9 and 10.0 mmol/L. With anything below that, you need carbohydrate units in the usual form of juice or bananas to return your blood sugar to the requested range.
Replenishing muscle glycogen stores
After exercising, blood sugar stores are depleted. This may frequently result in hypoglycaemia, since carbohydrates will move to the blood sugar stores, thus replenishing the muscle glycogen stores. Reducing the basal rate after exercising is thus recommended - for twice as long as the time of exercising.
The basic principle is: There are no hard and fast rules for diabetics for adjusting their insulin therapy to their chosen sport. However, with these tips, anybody can gently approach their own "personal" therapy.
- Lower your basal rate one or two hours before exercising.
- Measure before exercising:
→ Blood sugar below 8.3 mmol/L: Drink or eat 20 - 30 grams of carbs and wait 20 mins,
→ Blood sugar above 13.9 mmol/L: Check blood for ketones - if positive, correct high levels first and refrain from exercising until levels have dropped to your target range.
- Stop exercising with any symptoms of hypoglycaemia and take quickly absorbed carbohydrate 10 - 15 grams and check blood sugar again in 15 mins.
- Retain the lower basal rate for some time after exercising. Test your blood sugar: correct low values with carbohydrate intake, wait with raised levels due to the replenishing effect of the muscle glycogen.