Reading Your CGM
From once-a-year snapshot to minute-by-minute film
Continuous glucose monitors (Dexcom Stelo, G7, Abbott Libre) give a glucose reading every 1–5 minutes for 2 weeks from a small arm-patch sensor. For a long time CGM was diabetes-only. In 2024 Stelo became the first over-the-counter CGM — a pivotal moment for non-diabetic use.
What's 'normal' (for healthy adults)
Healthy-adult target ranges on CGM: average glucose 70–110 mg/dL; time-in-range (70–140 mg/dL) >85%; post-meal spikes ideally staying under 140, never over 180. Fasting baseline should hover 75–95. Overnight variability under 10% is a good-mitochondrial-health marker.
The metrics that matter more than spikes
Obsessing over every post-meal spike is counterproductive. What matters: (1) average glucose over 14 days, (2) time-in-range percentage, (3) 24-hour variability (coefficient of variation), (4) nocturnal glucose stability. A single spike is noise; consistent patterns are signal.
Match CGM metric to its meaning
Connect each metric to what it actually tells you.
Who benefits most vs. who doesn't
Biggest learning: people with prediabetes, elevated HbA1c, metabolic syndrome, or unexplained fatigue. Lower value: young metabolically-healthy athletes (your numbers will mostly be fine and you'll learn to obsess). Worth trying at least once if you've never worn one — 2 weeks gives you a baseline and insight you can't get any other way.
Key Takeaway
CGM isn't for everyone, but it's transformative for anyone with real metabolic concern. Focus on 14-day averages, time-in-range, and variability — not individual meal reactions. Your resting HR of {restingHr} already tracks autonomic recovery; CGM adds the metabolic layer.