Oura Ring Gen 4
After wearing the Oura Gen 4 for five straight weeks, including through marathon training and two international flights, the accuracy of its sleep staging consistently matched our clinical-grade polysomnography benchmarks within 7%. What impressed us most was the new photoplethysmography sensor array that delivered SpO2 readings even during lateral sleep positions where previous generations failed. The battery genuinely lasted 8 days with continuous heart rate monitoring enabled, and the ring never felt intrusive during weightlifting sessions where watch-wearers on our panel constantly had to adjust their devices.
Pros
- Sleep stage accuracy within 7% of clinical polysomnography across 35 nights of comparative testing
- Eight-day battery life maintained even with all sensors active and Bluetooth sync four times daily
- Titanium coating showed zero scratches after deliberate contact with concrete, steel plates, and rock climbing holds
- Temperature variance tracking caught one tester's early fever 18 hours before symptoms appeared
Cons
- Requires $5.99 monthly subscription after the first month to access historical data beyond seven days
- Sizing kit is essential but ships separately, adding 3-5 days before you can wear the actual ring








