How to Monitor Blood Sugar Before, During, and After Exercise

Proper blood sugar monitoring during exercise helps diabetics avoid dangerous lows or highs while pursuing safe weight loss. This guide provides step-by-step protocols using glucometers or CGMs, tailored for Type 2 diabetes management.

Before Exercise

Check blood glucose 15-30 minutes prior to activity, targeting 126-180 mg/dL for safety. If below 100 mg/dL, consume 15-30g fast carbs like glucose tabs or fruit juice, then retest after 15 minutes. Skip exercise if over 250 mg/dL with ketones; hydrate and consult your doctor.

During Exercise

For sessions longer than 30 minutes, test every 30-60 minutes to catch drops early. Treat readings under 100 mg/dL with 15g carbs and pause if symptoms like dizziness appear. CGMs offer real-time trends, reducing finger pricks.

After Exercise

Measure immediately post-workout, then at 1-2 hours, and up to 24 hours later due to delayed hypoglycemia from glycogen refill. Snack on protein-carb combos like nuts with yogurt if low; monitor overnight for intense sessions.

Practical Tips

Carry meter, carbs, and water always; adjust insulin if applicable. Log readings to spot patterns and share with your endocrinologist. Start with short, moderate activities like walking to build confidence.

1. https://www.mayoclinic.org/diseases-conditions/diabetes/in-depth/diabetes-and-exercise/art-20045697
2. https://diabetes.org/health-wellness/fitness/blood-glucose-and-exercise
3. https://www.uclahealth.org/medical-services/endocrinology/diabetes/type-1-diabetes/exercise-guidelines