Physical Activity
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
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.
