Exercise
Glucose Monitoring
Tracking Glucose during Exercise
Continuous Glucose Monitors (CGMs) can help you figure out the timing of before-exercise meals or snacks. They can also help you catch high and low blood sugars during exercise. Below we provide some information on how to utilize CGMs during your physical activity:
Tips for Sensor Use During Exercise
CGM (sensor) and fingerstick blood glucose can have an increased lag time during rapid changes in glucose (for example: during exercise)
- You can sometimes see around a 15-30-minute delay between CGM and fingerstick blood glucose during rapid changes (up or down) in blood glucose
When in doubt, fingerstick blood glucose measurement using a glucose meter is important!
- Particularly if you don’t trust the sensor reading
Generally, consider avoiding calibrations during exercise/activity or rapid changes in glucose
- Better to calibrate when glucose level is stable, flat trend arrows, not after a large meal or exercise
- Example: First thing in morning is generally good time to calibrate, if needed
- Can generally wait around 20-30 minutes after activity to see if CGM and fingerstick glucose had time to “catch up” to one another
Check out our Wisdom section to learn more about glucose monitoring and exercise:
I was adamant I’d stop using it once the baby was born but I actually started liking seeing my plots and avoiding the lows and highs.
Lolly
You can see where you are running high or low. Also the doctors can look at your recent numbers and see where you stand as far as your A1C levels.
Julie
As I began to trust the system more, I gave it more and more range to have control managing my diabetes, which has worked really well.
Dan
Visit these sections for more information
References
Zaharieva DP, Turksoy K, McGaugh SM, et al. Lag time remains with newer real-time continuous glucose monitoring technology during aerobic exercise in adults living with type 1 diabetes. Diabetes Technol Ther 2019;21(6):313-321, doi:10.1089/dia.2018.0364
Li A, Riddell MC, Potashner D, et al. Time Lag and Accuracy of Continuous Glucose Monitoring During High Intensity Interval Training in Adults with Type 1 Diabetes. Diabetes Technol Ther 2019;21(5):286-294, doi:10.1089/dia.2018.0387
Guillot FH, Jacobs PG, Wilson LM, et al. Accuracy of the Dexcom G6 Glucose Sensor during Aerobic, Resistance, and Interval Exercise in Adults with Type 1 Diabetes. Biosensors (Basel) 2020;10(10), doi:10.3390/bios10100138
Fokkert M, van Dijk PR, Edens MA, et al. Performance of the Eversense versus the Free Style Libre Flash glucose monitor during exercise and normal daily activities in subjects with type 1 diabetes mellitus. BMJ Open Diabetes Res Care 2020;8(1), doi:10.1136/bmjdrc-2020-001193
Da Prato G, Pasquini S, Rinaldi E, et al. Accuracy of CGM Systems During Continuous and Interval Exercise in Adults with Type 1 Diabetes. J Diabetes Sci Technol 2022;16(6):1436-1443, doi:10.1177/19322968211023522