Though initially developed for people with diabetes, the (relative) affordability of personal constant glucose monitoring devices is getting to the point where athletes and people looking to dial in their nutrition can soon use the science in a meaningful way. (Read more about the science behind glucose monitoring here.) While both the Levels and the Supersapiens devices below are made by the same company, Abbott, the models and platform are quite different.
Both use a small, 5mm hollow needle to effectively implant a thin, hair-like sensor filament under the skin on your arm. The sensor is attached to a plastic patch, roughly the size of a quarter, that sticks to your skin with a very strong, waterproof adhesive. The sensor only lasts 14 days, so you’ll need to reapply every two weeks (it doesn’t hurt much, as long as you change application sites). Also, the sensor is waterproof for swimming—even over an hour, despite the manufacturer’s warning. Just make sure you don’t snag it on clothing or a doorframe and rip it out.
$400 for first month, $200/mo. | levelshealth.com
The current version of Levels’ platform uses Abbott’s FreeStyle Libre with a sensor that stores up to eight hours of glucose information for periodic download via the built-in contactless near-field chip (NFC) reader on your smartphone. Because it’s a store-and-see situation, you won’t be able to view real-time blood glucose with this sensor. The Levels app displays your downloaded glucose data on a graph alongside any Apple Health-connected activities and lets you log your food intake for analysis against your data. The app also has a huge library of learning content to help you as you go.
The food logging setup is very good, and allows you to take pictures of your meals to simplify the process, and the library of learning content is incredibly vast. Levels also sends out a very helpful daily email summary with info on trends like metabolic score, average glucose, time in optimal range, variability, and more. Also, the sensor by itself is meant to withstand everyday use, but the included adhesive patches that you can place on top of the sensor to protect it is essential for triathletes. Even when putting on and taking off a wetsuit, the patch keeps the sensor in place.
The fact that you can’t see your glucose in real-time makes the Levels setup more of a post-mortem situation.
You can’t view your levels as you train or race, and having to download the information after every meal or event is a little bit of a chore—though it is as simple as holding your phone close to your arm. Levels’ analysis is also very DIY, as they provide you with a wealth of educational tools that range from the extremely basic to the way-too-in-depth, but their in-app analysis and insight tools are minimal compared to Supersapiens’.
Approximately $150-200/mo., depending on frequency | supersapiens.com
The Supersapiens we tested uses Abbott’s Libre Sense, a version of their CGM sensor that is not yet FDA approved for use in the U.S., but focuses more on the active customer—like triathletes—as opposed to people with diabetes—like the Libre Freestyle does. The result is a sensor that transmits data in real time (and stores up to eight hours of data) via Bluetooth LE over a tighter range of glucose levels than the Libre that Levels currently uses. Supersapiens’ app also lets you view your blood glucose levels live and provides excellent analytics and insights.
Obviously having a real-time, Bluetooth-compatible sensor is a huge boon for triathletes looking to dial in their nu- trition. Being able to see your glucose levels change as you train and race provides another dimension, and there’s talk of making the sensor compatible with a smartwatch or GPS computer—which would eliminate the smartphone from the equation. Device aside, the Supersapiens app does a much better job of showing trends, variability (important in glucose monitoring), and gives more on-the-go insights than the Levels app. Also, the Bluetooth connection is easily one of the most rock-solid we’ve ever seen with any device.
While the analytics on the Supersapiens app are stronger than the Levels version, the library of knowledge is far more basic, so it’s a little harder to know what to actually do with all of that info. That said, the graphs and insights are better, so you need to know less to make it work, but there’s still a lot of trial and error. Finally, as of this writing, Supersapiens relies solely on the Sense patch itself to stay on your skin, and it doesn’t offer an external adhesive patch to protect it like Levels does—an easy/cheap fix, but an important one for triathletes.
Both are very careful not to give “medical advice,” which seems like a little bit of a roadblock if you’re not willing to invest a lot of time in self-analyzing and researching the ins and outs of how your food and training interact with your glucose levels, but both Supersapiens’ sensor and app are much better suited for athletes willing to take the time and spend the money.