Technology applied to running is evolving at a dizzying pace. In recent years, we’ve seen GPS watches incorporate power meters, estimate our VO2 max, and analyze our recovery. Now, Garmin has taken things a step further by unveiling a patent that would enable non-invasive blood glucose monitoring through the wrist. In this article, we explore what this technology is, how it would work in Garmin watches, and why it could represent a revolution for runners—especially for those living with diabetes or looking to optimize their metabolic health.
What is HbA1c and why does it matter to runners?
HbA1c is the percentage of hemoglobin that has glucose attached to it. This metric is used in medicine to estimate average blood glucose levels over the last 8–12 weeks, because red blood cells have a lifespan of about 90 days. Unlike continuous glucose monitors that report real-time values, HbA1c reflects medium-term trends. For a runner with diabetes or prediabetes, knowing their HbA1c can help them adjust diet and training over the long term and reduce the risk of hypoglycemia or hyperglycemia. Even for runners without metabolic issues, keeping glucose within healthy ranges supports recovery, hormonal health, and the ability to sustain prolonged efforts.
How Garmin’s needle-free glucose monitoring would work
Garmin’s patent describes a system based on pulse spectroscopy. The watch emits three different wavelengths through its photoplethysmography (PPG) sensor and measures how light is reflected in the tissue. By comparing the ratio between the alternating (AC) and continuous (DC) components of each signal, the algorithm can differentiate oxygenated hemoglobin, deoxygenated hemoglobin, and glycated hemoglobin, and solve an equation that calculates the HbA1c percentage. According to details shared by specialized outlets such as The5krunner and Gadgets & Wearables, this approach does not replace continuous glucose monitors; instead, it provides a weekly or monthly HbA1c update, ideal for tracking trends and evaluating the effect of nutrition or training. The key difference is that it would not measure rapid spikes after a meal, but rather the accumulated average—so the goal is to improve long-term health.
The patent builds on sensors and algorithms that already exist in high-end Garmin watches, so it wouldn’t require entirely new hardware; however, speculation suggests it could debut with the sixth generation of the Elevate sensor and possibly in future models such as the Fenix 9 or the Venu 5. Until then, Garmin will continue collaborating with continuous glucose monitor manufacturers like Dexcom to provide real-time data for users who need it.
Potential benefits for runners
- Diabetes management: runners with type 1 or 2 diabetes could receive consistent feedback on the effectiveness of their treatment and detect changes in glycemic control without frequent lab visits.
- Nutrition optimization: seeing how diet affects long-term glucose levels makes it easier to adjust carbohydrate intake before and after training. Keeping HbA1c in a low range can improve recovery and reduce inflammation.
- Injury and fatigue prevention: disrupted metabolism can influence muscle repair and the nervous system. Monitoring glucose makes it easier to identify habits that could lead to overload, energy crashes, or prolonged fatigue periods.
- Integration with existing metrics: Garmin could combine HbA1c with indicators like Body Battery, heart rate variability, or training load to provide more personalized recommendations. Imagine an alert suggesting rest or plan adjustments when it detects that your average glucose has drifted.
Challenges and release timeline
- Accuracy and calibration: determining glucose via light is sensitive to factors such as strap pressure, skin tone, or sensor position. Garmin has already filed patents to compensate for pressure, but improved hardware will likely be required.
- Medical approval: any device that provides health-related data must pass regulatory review from bodies such as the FDA. This could extend the timeline by several years; some analysts point to 2027 as a likely target.
- Initial focus: since it targets users with diabetes or prediabetes, early models may prioritize accuracy over sport features. For runners, this means it will not replace the continuous glucose monitors that some athletes already use to adjust fueling during races.
Comparison with other emerging technologies
Garmin isn’t the only company researching needle-free methods. Start-ups like PreEvnt are working on breath analyzers that measure volatile metabolites to estimate glucose, and other brands are exploring skin-based biosensors. The fundamental difference is the goal: while breath monitoring aims to provide near real-time data to optimize carbohydrate intake during competition, Garmin’s approach prioritizes long-term metabolic health. For runners, both strategies could complement each other: use a real-time glucose monitor on race day and the watch’s HbA1c estimate to review weekly trends.
Practical tips while we wait
- Adjust your diet: prioritize high-quality carbohydrates (whole grains, fruit, vegetables) and avoid refined sugars outside of training. Keep track of how you feel after different meals and adjust portions accordingly.
- Manage your training: use metrics like heart rate, running power, and perceived exertion to avoid overdoing it. Our guide on how to train by watts explains how to maintain a steady effort even on changing terrain; you can read it in this article.
- Listen to your body: recovery and sleep quality are key signals. If you notice persistent fatigue, mood changes, or low energy, review your diet and reduce training intensity.
- Track how you feel: HbA1c is a multi-month average; in the meantime, logging your sensations will help you spot patterns. Tools like SnapRace allow you to create training diaries and sync health data, making holistic analysis easier.
- Consult professionals: if you suspect blood glucose issues, speak with a doctor or sports nutritionist. They can recommend specific tests and continuous monitoring if needed.
Garmin’s upcoming non-invasive glucose monitoring promises to change the way we interpret our health data. For runners living with diabetes or looking to optimize performance, having an HbA1c estimate from the wrist would be a valuable tool for making informed decisions. Although we’ll still have to wait a few years, the trend is clear: wearables are becoming increasingly complete allies.
In the meantime, don’t forget that peak performance is built day by day. Keep training smart, take care of your nutrition, and try apps like SnapRace to plan your workouts, race virtually, and analyze your progress. Stay tuned to our blog for all the latest updates on running technology.