Garmin has reportedly acquired Moxy Monitor, the company behind the muscle oxygen sensor that a small group of serious endurance athletes already train with. Neither Garmin nor Moxy has announced it, and that silence is less suspicious than it looks.
The report originated with a specialist Garmin publication and was picked up by TechRadar this week. It attributes the acquisition to "a source with direct knowledge of the transaction." Garmin has made no comment. Moxy's founder, asked about it, reportedly directed questions to Garmin rather than answering them himself, which is the closest thing to a confirmation anyone has offered.
So treat this as reported rather than established. What follows is why it is credible, and what it would actually change.
Why There Was No Announcement
The obvious objection to a Garmin acquisition story is that Garmin is a public company. It reports to the SEC. A purchase would show up.
That is true for acquisitions that matter to Garmin's financial statements, and it is not true for this one.
Garmin is a business with roughly $8 billion in annual revenue. Moxy Monitor is a small, specialist company, and the transaction is reportedly small enough that Garmin's disclosure obligations were never triggered. Under SEC rules, the disclosure threshold is built around materiality: a deal has to be significant relative to the acquirer's business before an 8-K or detailed financial disclosure is required. A company the size of Moxy does not come close.
That makes a quiet close the expected outcome rather than a red flag. It also explains the contrast with Garmin's other 2026 acquisition news, which did come with press releases. Garmin's purchase of MYLAPS, the Dutch timing and live-tracking company, was announced publicly. So was the acquisition of Applied Ballistics, which we covered when Garmin bought the ballistics solver behind its tactical watches.
Two announced deals and one silent one is not inconsistency. It is how materiality works.
The Trademark That Came First
There is independent evidence that Garmin has been working toward muscle oxygen for months, and it predates the acquisition report.
In February 2026, Garmin filed a trademark for "Muscle Battery" describing an algorithm built around muscle oxygen saturation, or SmO2 data. Notebookcheck covered the filing at the time, noting that the sensor type involved, near-infrared spectroscopy, is "not currently available on any Garmin wearable," which points to an entirely new product rather than a feature update.
A trademark filing is not a product. But it tells you Garmin built the naming and the algorithmic concepts for muscle oxygen before it reportedly bought the company that has spent over a decade commercializing it.
Why Muscle Oxygen Is Hard, and Why That Matters
SmO2 is a genuinely different measurement from what any wrist wearable does today.
Moxy's sensors use near-infrared spectroscopy to read oxygen saturation in a specific working muscle. Coaches and athletes use it to set intensity, find thresholds and time recovery between efforts. The reason it has stayed niche is not that it is unproven. It is that you cannot measure it from the wrist. Light has to pass through the muscle being measured, which means a sensor strapped over a quad or a calf, not a watch on your arm.
That single physical constraint explains everything else in this story.
Garmin already reads SmO2 today, from Moxy sensors and from Train.Red hardware, over the ANT+ muscle oxygen profile, and displays the values on compatible watches and Edge computers. So the most immediate thing an acquisition changes is not a watch feature at all. It is the quality, integration and support of the third-party data Garmin already shows.
Anything more than that requires new Garmin hardware: a strap or a pod, sold separately from the watch. That is a longer road, and it is the reason this story matters more for Garmin's product roadmap than for your next software update.
Whoop Got There First
The competitive context is what makes this look less like opportunism and more like catching up.
Whoop has patented its own SmO2 strap, which means Garmin's main rival in the subscription-athlete market is already building in this direction. Whoop also bought its way in: it acquired the assets and team of Humon, a muscle oxygen startup, in 2020, and Humon's co-founder and CTO, Daniel Wiese, became Whoop's Director of R&D. The patent naming the Humon founding team is part of that story.
The category has a graveyard behind it. Humon Hex and BSX Insight both tried and failed to bring SmO2 to a mainstream audience, which is exactly the risk a big company avoids by waiting. Today the survivors are Moxy, which is the only device with published scientific validation for absolute SmO2, and Train.Red, a spin-off from Artinis Medical Systems that packages laboratory-grade NIRS optics into a small consumer sensor.
Buying Moxy gets Garmin validated sensor technology, more than a decade of proprietary research, and a credible position in a category its rival has already staked out, without spending years on a sensor program that two other companies already abandoned.
What Would Actually Change
Three levels of outcome, from most likely to most interesting.
The near-term change is refinement. Garmin continues reading SmO2 from third-party straps over ANT+, now with the company that makes the reference sensor inside its own portfolio. Better integration, better data handling, and probably better support for third-party sensors on the app side. Not glamorous, and it may be all that happens for a while.
The interesting change is new hardware. A Garmin NIRS sensor would be a standalone product, likely a strap or a small pod, aimed at the same athlete paying for a Fenix 9 Pro or a Forerunner 970 today.
The strategic change is the subscription layer. Garmin has been building out Connect+ features and buying software companies for a year, and it now sells a screenless band of its own in the same subscription-adjacent space. Muscle oxygen is a metric that produces a numerical score an athlete can train against, which is precisely the kind of thing a subscription tier is built to sell.
What We Do Not Know
Plenty, and it is worth listing honestly.
There is no confirmed purchase price. Neither company has confirmed the deal exists. It is unknown whether Moxy would continue selling to athletes and researchers directly, or whether its technology gets absorbed into Garmin products and the standalone business winds down. Moxy's sensor has research and clinical uses well outside sport, and Garmin has no obvious plan for those.
There is also no timing on hardware. If a Garmin NIRS strap is coming, it has not leaked, and Garmin's filings so far cover the algorithm and the name rather than a device.
Bottom Line
Reporting this week says Garmin has acquired Moxy Monitor, the muscle oxygen sensor company, sourced to a person with direct knowledge and picked up by TechRadar. Neither company has confirmed it, and no announcement should be expected: the deal is reportedly small enough that Garmin's SEC disclosure obligations were never triggered, which is why this looks quiet rather than hidden.
The supporting evidence is a February 2026 Garmin trademark for "Muscle Battery" describing an SmO2 algorithm, filed months before the acquisition report. SmO2 cannot be read from the wrist, so it requires separate NIRS hardware, which means the near-term effect is better third-party sensor support and the interesting effect is a new Garmin product category. Whoop has already patented its own SmO2 strap, and Garmin spent the last decade reading competitor hardware instead of making its own.
If it is real, this is Garmin buying its way into a metric it has been unable to measure and its rival has been building for five years.
Sources: TechRadar's report on the Moxy Monitor acquisition and its implications for Garmin's product roadmap, published September 2026, citing a specialist Garmin publication's sourcing to a person with direct knowledge of the transaction; Notebookcheck's coverage of Garmin's February 2026 "Muscle Battery" trademark filing and the near-infrared spectroscopy sensor requirement for SmO2 measurement; Garmin's published Connect IQ and ANT+ muscle oxygen profile support documentation for third-party SmO2 sensors; Applied Ballistics' product documentation for its embedded sensor ecosystem; and public records and reporting on Whoop's 2020 acquisition of Humon's assets and team, its SmO2 strap patent, and the earlier commercial failures of Humon Hex and BSX Insight.