Beyond Diabetes: CGMs for Performance
Continuous glucose monitors are now available over-the-counter for non-diabetics. They reveal how food, exercise, sleep, and stress affect your blood sugar. We tested 5 CGMs on athletes.
Testing Protocol
- Accuracy: Compared to fingerstick glucose meter (30 readings per CGM)
- Exercise: Worn during running, weightlifting, cycling
- Meals: Response to standardized meals (high carb, high fat, mixed)
- App quality: Data visualization, actionable insights, food logging
- Comfort: 14-day wear, skin irritation, sleep disruption
Top Picks
1. Levels CGM — Best Overall for Fitness
Uses Abbott Libre 3 sensor (most accurate OTC). The Levels app provides the best food scoring and metabolic insights. AI-powered meal analysis.
Accuracy: MARD 8.8% (best in test)
App: 9/10 — best food scoring system
Sensor life: 14 days
Price: $199/month (2 sensors + app)
2. Nutrisense — Best for Data Geeks
Raw glucose data export, detailed analytics, and optional dietitian consultations. Best for those who want full data control.
App: 8/10 — most detailed analytics
Price: $299/month
3. Signos — Best Budget
Uses Libre 3 with a simpler app. Good basic insights without overwhelming data. Most affordable OTC CGM program.
Price: $149/month
What CGMs Taught Us
- Same food affects different people differently
- Walking 10 minutes after meals reduces glucose spikes by 30%
- Sleep deprivation raises fasting glucose by 10-15 mg/dL
Bottom Line
The Levels CGM provides the best combination of accuracy and actionable insights for athletes. Budget-conscious users should try Signos.
