Exercise Glucose Drop Estimator
Estimate how much your blood glucose may drop during exercise - and whether it's safe to start your session.
Educational estimator only - not medical advice.
Range: 5-180 minutes
Typical safe range to start: 100-250 mg/dL
Fill in your exercise details above to see your estimated glucose drop.
This estimator uses research-based average glucose drop rates per exercise type, adjusted for intensity and the presence of active insulin. Base drops per 30 minutes:
These are scaled by intensity (Light x0.7, Moderate x1.0, Vigorous x1.3) and session duration, with diminishing returns after 60 minutes. If active insulin is on board, an additional x1.5 multiplier is applied - insulin significantly amplifies exercise-driven glucose drops.
Important: Individual responses vary widely. Factors like stress, recent meals, CGM lag, and fitness level all affect the outcome. Aerobic exercise generally lowers blood glucose; high-intensity anaerobic exercise can temporarily raise it due to adrenaline.
Post-exercise late hypo: Blood glucose can continue dropping for 6-12 hours after exercise as muscles replenish glycogen stores. Always monitor after sessions.
Chapter 11 of the FOD Starter Guide covers exercise and blood sugar in depth - including snack strategies, timing your workouts, and managing the post-exercise late hypo window. Essential reading for active people with diabetes.
FOD Starter Guide - Ch. 11This calculator is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Exercise affects blood glucose differently for every individual. Always consult your healthcare provider or certified diabetes educator before changing your exercise routine, especially if you take insulin or glucose-lowering medications. Never exercise if your blood glucose is below 100 mg/dL (5.6 mmol/L) without first consuming carbohydrates.