Topic
Wearables, tracking, and the technology of health.
The American Heart Association's own December 2025 statement says the smartwatches and rings promising cuff-free blood pressure readings aren't validated enough yet to trust for diagnosis.
Two independent validation studies tested Apple Watch's wrist-based VO2 max against real lab tests, and the gap was biggest for exactly the people most likely to trust the number.
Oura, Whoop and Apple Watch all now lead with heart rate variability and readiness scores, but a leading cardiologist says the scores themselves are unvalidated.
Rings like Oura are genuinely good at telling you how long you slept, but the deep sleep and REM breakdown they report can miss the mark by a lot.
Sweat biosensors promise blood-level data with no needle. The first one measures lactate, its validation claim has no published study behind it, and the biomarkers people actually want are still only a roadmap.
Oura now costs up to $499 plus a subscription and Whoop bundles its hardware into three membership tiers up to $359 a year, so the real question isn't which tracks better, it's which one you'll actually keep paying for.
Circular's Ring 2 and the PIN Pulse promise needle-free glucose and blood pressure, but no smart ring has been proven, or cleared, to measure either.
Stelo and Lingo put an $89-a-month window on your blood sugar, but the spikes they flag in red are usually your body working normally, and the proof they help people without diabetes barely exists.