The finger is one of the most accurate places on your body to measure cardiovascular data, and Oura has spent over a decade engineering hardware specifically to take advantage of that.
The finger is one of the most accurate places on your body to measure cardiovascular data, and Oura has spent over a decade engineering hardware specifically to take advantage of that.
The result is data I actually trust and act on.
The Oura Ring 4 is the most significant hardware upgrade in the company’s history. The Smart Sensing platform uses an 18-pathway multi-wavelength photoplethysmography system with red and infrared LEDs that delivers a 120% improvement in blood oxygen signal quality, a 31% improvement in nighttime heart rate accuracy, and measurably better performance across different skin tones than any previous generation.
The interior is now completely smooth titanium, with no sensor bumps and no pressure points, which means you can wear it during training, during sleep, and throughout the day without thinking about it. An eight-day battery life means you rarely need to charge it.
It tracks your readiness score, sleep score, HRV, resting heart rate, skin temperature deviation, and sleep stage breakdown compared to your personal baseline. The readiness score in particular is something I’ve learned to take seriously: when it’s low, I pull back, and when it’s high, I push. That discipline alone has meaningfully changed how I train and recover.
Daytime stress tracking, cardiovascular age estimate, VO2 max estimate, and automatic detection of over 40 workout types round out a picture that no single metric could give you alone.
With over 2.5 million rings shipped and validation against polysomnography at institutions like the University of Tokyo and National University of Singapore, this is a genuinely insightful tool for understanding your body.
“It’s no secret that the Oura ring is my #1 choice for self-quantification, due to a huge number of variables, including…
…extreme “out-of-the-box” ease of use…
…the fact that it doesn’t produce a cell-damaging WiFi and Bluetooth signal…
…the extreme sleep tracking accuracy that beats the pants off any other tracker on the market…
…the new Oura “team” dashboard that allows coaches to monitor an entire team or personal trainers to monitor all their clients…
And, this beautiful wearable allows you to track body temperature, heart rate variability, calories, steps, respiration, extremely accurate sleep cycles and much, much more.” – Ben