Chips & Hardware
Oura adds Cardio Effort and VO₂ max to its fitness tracking
Oura is rolling out two new metrics, Cardio Effort and VO₂ max, to show users how their workouts affect their bodies beyond simple duration and heart-rate zones.
Smart-ring competition is intensifying, and Oura announced Tuesday that it’s expanding workout tracking with two new metrics: Cardio Effort and VO₂ max. Rivals like RingConn and Ultrahuman have been chipping away at Oura’s longtime lead in the category, and the company is responding by pushing further into advanced training data.
Cardio Effort measures how much strain a workout places on the cardiovascular system, aggregated weekly against each user’s own baseline. Oura frames the shift as moving past “how many minutes did I move” toward a read on whether someone is maintaining, building or overdoing their fitness. Because the metric weighs both intensity and duration together, a short, hard workout can score similarly to a longer, easier one. It splits into two pieces — a per-workout score and a weekly total, the latter sorted into bands from “Light” to “Reaching” — built from elevated heart rate measured against a person’s long-term resting rate rather than estimated max-heart-rate figures, with personalized ranges set from recent activity. Cardio Effort is rolling out to Oura Ring Gen3 and newer models.
VO₂ max estimates long-term fitness by capturing how efficiently the heart, lungs and muscles deliver and use oxygen during exercise — a figure that used to require a lab test or a six-minute walk test but which Oura can now estimate passively from GPS-enabled workouts. After five qualifying activities, users get an initial estimate they can track in ml/kg/min inside the Health Heart Hub, along with a category (Low, Fair, High or Peak), its trend over time, and alerts when it shifts meaningfully or holds steady. VO₂ max is launching in Oura Labs, the company’s testing ground for experimental features, limited to Gen3 and newer rings.
Oura says the two metrics are meant to work together, pairing how hard a workout is with how that effort accumulates over time.
Why it matters
As rivals narrow the gap in smart rings, Oura is betting that deeper physiological insight — not just more sensors — is what keeps subscribers from switching.