FDA eases wearable rules: Oura lobbies, sensors err — stay sceptical

The US Food and Drug Administration (FDA) updated its "General Wellness Policy for Low Risk Devices" on 6 January 2026. Wearables like the Oura Ring, Apple Watch, or devices from Garmin and Polar are now allowed to do more without being classified as medical devices. Oura is celebrating it as a breakthrough. The uncomfortable truth: the easing has less to do with consumer protection than with industry lobbying. And the measurement technology behind it is less precise than the marketing departments would have you believe.

1. What the FDA actually changed

The new guidance broadens the definition of a "General Wellness Product". A product qualifies if it generally promotes health or healthy activities — or supports a lifestyle that demonstrably lowers the risk of chronic diseases. Sounds harmless, but has concrete consequences in three areas.

Blood pressure: Non-invasive wearables that merely estimate blood pressure — for example via photoplethysmography (PPG, i.e. light measurement at the skin) — can now count as wellness products. The condition: they do not diagnose diseases such as hypertension. As recently as 2025, the FDA had explicitly warned that blood pressure estimates do not belong in the wellness category.

Glucose: Products that measure or estimate blood sugar are also allowed in the wellness category — provided they are intended exclusively for nutrition, fitness, and general well-being in healthy people. Explicitly not for people with diabetes or pre-diabetes.

Notifications and alerts: Wellness devices are allowed to indicate when a doctor's visit might make sense. But: they must not name specific diseases, state diagnostic thresholds, recommend treatment, or offer continuous monitoring of chronic conditions.

On paper, this sounds like a sensible middle ground. In practice, it shifts the line between wellness gadget and quasi-medical device — and this shift does not happen without outside pressure.

2. Oura's lobbying: 1 million dollars well spent

Oura did not just welcome this change — the company actively worked towards it. CEO Tom Hale published an opinion piece in the Wall Street Journal in December 2025 calling for a new category of "Digital Health Screeners" to fill the gap between wellness products and regulated medical devices. According to Politico, the lobbying budget grew from 40,000 dollars (2024) to over one million dollars in 2025. The US Department of Defense is already Oura's largest customer.

Oura is not alone. Apple benefits directly from the easing — features like non-invasive glucose monitoring or blood pressure estimation in the Apple Watch become easier to ship without having to go through the full FDA clearance process. Tellingly, WHOOP VP Alex Vannoni warned of an "unregulated and undefined category" and urged caution.

3. The real problem: how accurate are wearables really?

The regulatory question is one thing. The measurement reality is another. And this is where it gets interesting for the fitness community — because the limits of PPG technology affect practically every wearable on the market.

3.1 PPG vs. ECG: physics cannot be marketed away

Heart rate variability (HRV) is based on the precise time difference between individual heartbeats — the so-called inter-beat intervals (IBI). An ECG detects the electrical R-peaks of the heart directly and very accurately. PPG sensors (photoplethysmography), as used in rings, watches, and bands, by contrast measure indirectly via light reflection at the skin. That makes them susceptible to movement, sweat, circulation fluctuations, and poor skin contact.

Studies show: under controlled conditions — especially during sleep — PPG wearables can reach high correlations with ECG for metrics like rMSSD (Root Mean Square of Successive Differences, a common HRV measure), sometimes above 0.9. Validation studies on Oura (including Altini & Kinnunen 2021, de Zambotti et al. 2019) confirm this for overnight measurements. But the caveat is decisive: this only works at rest, with artefact-filtered data, and averaged over longer time windows. Short-term HRV over five minutes, frequency parameters like LF/HF, or measurements during movement — accuracy drops off quickly there.

3.2 ECG is not perfect either — something manufacturers like to leave out

Here comes the point that many manufacturer narratives elegantly skip: even with ECG and chest strap, HRV is extremely sensitive. Researchers have been warning for years that even minor movement artefacts significantly distort HRV calculations — regardless of whether the input comes from a chest strap or a wearable. Extrasystoles (extra heartbeats) must be carefully detected and corrected, otherwise values like rMSSD get systematically skewed. Methodologically sound studies therefore record HRV data in controlled rest, a standardised position, and with dedicated artefact software.

Concretely: HRV is intrinsically sensitive, regardless of measurement technology. PPG wearables add optical confounders on top of this baseline problem. The combination makes single readings outside of resting conditions scientifically questionable.

4. Recovery scores: how much is marketing, how much is substance?

Garmin Body Battery, WHOOP Recovery, Oura Readiness Score, Fitbit Daily Readiness — all the major manufacturers sell proprietary composite scores that distil HRV, resting heart rate, sleep, and activity data into a single number. The problem: no manufacturer discloses exactly how these scores are calculated. And the validation picture is thin.

Studies show that these scores often correlate only weakly — or not at all — with independent recovery questionnaires. Spetz et al. (2025) found that wearable data including recovery scores correlate only weakly with the POMS questionnaire (Profile of Mood States) — external factors interfere heavily, and subjective ratings remain essential. Doherty et al. (2025) directly compared Oura Readiness, Garmin Training Readiness, and WHOOP Recovery: validation against perceived recovery was consistently weak, and the proprietary algorithms make a genuine comparison impossible. Further analyses show that readiness scores explain only 8 to 35 percent of the variance in subjective recovery measures like TQR (Total Quality Recovery). If you wear several devices at once, you get completely different recovery percentages. That speaks to proprietary black boxes — not to robust science.

A realistic estimate: roughly a third of these scores is based on solid data and experience, a third is interpolation and heuristics, and a third primarily serves marketing and ecosystem lock-in.

5. The underrated metric: your resting heart rate

Amid the hype around HRV analytics and AI-driven recovery scores, one of the oldest metrics in sports medicine is systematically underrated: morning resting heart rate. It is robust, cheap to measure, and surprisingly informative.

A consistently low resting heart rate indicates good cardiovascular adaptation. An elevated resting heart rate — even 5 to 10 beats above your individual baseline — reliably correlates with accumulated fatigue, stress, or oncoming immune weakness. Often one or two days before you notice the performance drop.

Research — for example Buchheit's widely cited 2014 paper on HRV-based training management — shows: resting heart rate and HRV are complementary indicators that work better in combination than either metric alone. In studies on training management, multi-day averages of resting heart rate and HRV deliver equally good or better results than HRV on its own — especially when the HRV measurement is not perfect, as with PPG watches. Resting heart rate is therefore not obsolete. It is a solid, often more robust part of the overall picture, which HRV usefully complements — not replaces.

The good news: your finger on your neck at 6 a.m. — or simply the resting heart rate on your smartwatch — gives you a data point no proprietary recovery score can replace.

6. What is positive about the FDA change?

For all the justified scepticism: the new guidelines also have sensible aspects. They create clear boundaries for the first time where there was previously a grey area. Manufacturers now know more precisely what they can and cannot do — which paradoxically also reduces the risk of misleading marketing claims, because the FDA explicitly defines that wellness products must not name diseases, state diagnostic thresholds, or recommend treatment.

For users, this potentially means: more features on the device without manufacturers having to wait years for medical device clearance. Blood pressure trends, metabolic tracking, and personalised notifications could arrive faster. Oura emphasises that it continues to rely on scientific validation by third parties — commendable, as long as it does not remain mere PR rhetoric.

The new clarity also forces manufacturers like WHOOP — which have raised eyebrows in the past with medical claims — to adjust their communication. The FDA rules are not an invitation to the Wild West — they are a reordering with clear boundaries.

7. Verdict: more features, more personal responsibility

The FDA easing is real, and Oura actively helped shape it. That is neither scandalous nor surprising — it is industrial policy as it has worked for decades. What matters is what you as a user make of it.

New features like blood pressure estimation and glucose tracking will come. They can offer useful orientation — as long as you treat them for what they are: estimates based on optical sensors, not medical diagnoses. The underlying PPG technology has physical limits that no algorithm can fully compute away.

For your training, this means concretely: use wearable data as one building block among several. Trust long-term trends over weeks, not individual readings. Take your morning resting heart rate seriously — it is robust, free, and underrated. And if the recovery score looks great but you feel completely wiped out, trust your body.

Spoiler: it is more complicated than a number on your wrist.

Sources: Oura Blog – How New FDA Guidance Unlocks Innovation at Oura (10/02/2026) · FDA – General Wellness Policy for Low Risk Devices (06/01/2026) · AppleInsider – Oura's FDA lobbying benefits Apple Watch (09/02/2026) · MedTech Dive – FDA exempts more wearable, AI features from oversight (08/01/2026) · MD+DI Online – FDA's New Rules for Wearables (08/01/2026) · Buchheit, M. (2014): Monitoring training status with HR measures. Int J Sports Physiol Perform, 9(6). · Altini, M. & Kinnunen, H. (2021): The Promise of Sleep: A Multi-Sensor Approach for Accurate Sleep Stage Detection. Sensors, 21(5). · de Zambotti, M. et al. (2019): The Sleep of the Ring: Comparison of the ŌURA Sleep Tracker Against Polysomnography. Behav Sleep Med, 17(2). · Spetz, E. et al. (2025): Validating Subjective Ratings with Wearable Data. PMC12696214. · Doherty, C. et al. (2025): Readiness, recovery, and strain: evaluation of composite health scores. Sports Med.