Diabetes, Sport and Blood Sugar Levels

Having diabetes doesn't mean you can't play sports

When people with diabetes participate in sport, whether they are children or adults, it is quite possible that they will experience low or high blood sugar levels.

If you are on blood glucose lowering medication (e.g. tablets or insulin) it is recommend to more frequently test your blood glucose levels during and after exercise to see how your sugar levels are responding.

Be wary of hypos

Low blood sugar, hypoglycemia, can occur during or after exercise when the body has used a high level of its stored sugar.

People taking glucose lowering medications should be aware of the risk of hypoglycemia that sport can present.

Sport can cause the body to be more sensitive to insulin for up to 48 hours after exercising and people on insulin may need to take this account, particularly when next going to sleep after exercise.

Hyperglycemia and sport

High blood sugar, hyperglycemia, can also occur during exercise, particularly after short bursts of strenuous activity.

Strenuous activity produces a stress response which sees the body producing glucagon to raise blood sugar levels to provide the muscles with energy in the form of glucose.

If your sugar levels are above 14 mmol/l, it may be advisable to do a ketone test as exercise can increase the production of ketones. If your ketone levels are high, it is advisable to do less strenuous activity such as walking.

Symptoms of high and low blood sugar

All diabetics taking part in sport need to be aware of the influence of hypoglycaemia and hyperglycaemia, as well as the symptoms of each.

Hypoglycemia or low blood sugar symptoms include:

• Sweating
• Shakiness
• Lightheadedness
• Anxiety
• Hunger
• Headache
• Lack of concentration.
• In severe cases, fainting and seizures can occur.

Hyperglycemia or high blood sugar symptoms include:

• Dehydration
• The need to urinate more often
• Weakness or lethargy
• Blurred vision

Effects of different types of sport on blood glucose levels

Different forms of sport may affect your blood glucose levels in different ways.

It is not uncommon for upper body exercise to have a different effect on your levels to lower body exercise.

How strenuous the exercise is can also make a difference to how much your sugar levels vary.

The best way to see how different activities affect your levels is to regularly test your blood sugar during (where possible) and after exercise.