Oura just took a perfectly good smart ring and turned it into the kind of friend who asks if you've done your cardio today, then shows up with a graph. Its two new features, Cardio Effort and automatic VO2 Max, are not here to tell you how many miles you crushed or whether your Strava friends should be jealous. They are here to ask a quieter, more interesting question: what is your heart actually doing in there, and is it getting better at its job? This is the kind of feature that makes you wonder why nobody thought to ask it before, which is exactly the kind of thing we love around here. It also makes us think of the Wyze scale that lets your feet land anywhere and still get a body composition reading, or the Shelly radar sensor that tracks ten bodies without a single camera. All three devices are doing the same quiet rebellion: they are pulling useful data out of thin air, or a finger, or a glass plate, without asking you to change your routine.
Here is the thing that makes Cardio Effort genuinely spooty. Most fitness trackers measure your output, speed, distance, calories burned, which is basically the wearable equivalent of a gold star. Oura is measuring input instead: how hard your cardiovascular system worked to produce that output. That is a subtle pivot, but it is a profound one. It means two people running the same route at the same pace will get different scores, because their hearts are different. It means a bad night of sleep or a stressful morning will show up in your workout data, because your cardiovascular system is not a machine that ignores context. And it means you can stop chasing arbitrary pace targets and start asking whether your heart is adapting, recovering, and getting stronger. That is the kind of metric that actually helps you train smarter, not just log harder.
The automatic VO2 Max upgrade, meanwhile, turns a metric that used to require a lab, a mask, and a treadmill into something your ring just figures out while you sleep. That is genuinely wild. VO2 Max has always been the gold standard for cardiovascular fitness, but it was also the one that required you to breathe into a tube until you wanted to die. Oura is now estimating it automatically, based on your resting heart rate, heart rate variability, and other overnight signals. Is it as accurate as a lab test? Probably not. But it is more accessible, more frequent, and more useful for tracking trends over time than a single number from a test you take once a year. That is the trade-off we love to see: imperfect data that you actually use, versus perfect data that sits in a drawer.
Here is the catch, and we are not going to swallow the hype on this one. Both features require an active Oura membership, which means you are paying a monthly fee to access data your own hardware already collected. That is a hard pill to swallow, especially when the hardware itself is not cheap. And the features are only available on Gen 3 and later rings, which means anyone still wearing a Gen 2 is looking at an upgrade bill plus a subscription to get these new tricks. The question we are left with is not whether the features are good, they are, but whether Oura will ever let you own your own data without a recurring payment. For now, the answer is no. Stay spooty, and keep one eye on the fine print.