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Monitoring blood sugar for exercise

Overview

Certain exercises can increase stress on the body hormone release, leading to temporary rise in blood sugar production.

Examples of such exercises include brief but intense exercises such as sprinting and powerlifting.

Usually a small increase that lasts for 1-2 hours is not a concern if your pre-exercise blood sugar level was not excessively high.

Before exercising

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If your blood sugar level is less than 4.0 mmol/L (hypoglycaemia)

Delay your exercise
Perform the 15/15 rule to treat hypoglycemia
Do not exercise if you:
- feel unwell
- had an hypoglycaemic episode in the last 24 hours that required someone’s assistance
- are exercising alone or engaging in a potentially unsafe exercise

15-15 RULE

Consume 15g of fast-acting sugars
Check your blood sugar level after 15 minutes

Examples of fast-acting sugars (carbohydrates):

3 teaspoons of dextrose powder/table sugar in 120ml of water
½ can of regular soft drink
1 can of low-sugar soft drink
½ glass (150ml) of fruit juice
3 soft/jelly sweets

If your blood sugar level is 4.0 – 5.5 mmol/L

Exercise with caution
Have a light snack (15 - 30g of long-acting sugars, e.g., 3 pieces of biscuits and milo) and wait 15 minutes before exercising
If exercising duration for more than 30 minutes, consume additional carbohydrates

Note: If you are on insulin and/or sulphonylurea, standby 15g of fast-acting sugars due to a higher risk of hypoglycemia occurring with exercise.

If your blood sugar level is 5.6 – 15 mmol/L

This is a good range!
Go ahead with your exercise, but monitor signs and symptoms throughout as you do so
If your session lasts longer than 60 mins, you may need additional carbohydrates

Pro Tip: Blood sugar levels between 5.6 to 15 = Good to Go!

Note: If you are on insulin and/or sulphonylurea, standby 15g of fast-acting sugars due to a higher risk of hypoglycemia occurring with exercise.

If your blood sugar level is more than 15 mmol/L (hyperglycaemia)

If you are feeling well and have taken your usual medications, proceed to exercise with caution
Monitor your glucose trend and increase your fluid intake

CAUTION:

If you are on insulin and sulphonylureas, it is best to consult a physiotherapist for a guided exercise session before determining the appropriate blood sugar levels for exercise, as there are many other factors to consider.

Pre-exercise medication

Medications

Consume your medications as prescribed by your doctor. Do not skip medications and attempt to replace it with exercise.

Consult your doctor for a medication review if you are changing your exercise routine.

Important Medicine

If you are on insulin, sulphonylurea (e.g., gliclazide, glimepiride, glipizide and tolbutamide) or meglitinides (e.g., repaglinide), your blood sugar levels may decrease faster as compared to other medications.

Start easy, monitor signs and symptoms closely, and avoid prolonged exercise.

Consult your doctor for a medication review if you experience signs and symptoms of hypoglycaemia.

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CONTRIBUTED BY

Ministry of Health