March 24th 2026
Gentler Streak brings Cardio Fitness to the Wellbeing tab - with a focus on its trend
Gentler Streak, the award-winning health and fitness app, is about to introduce Cardio Fitness, aka VO₂ max, as a new health metric. The feature is built around a deliberate philosophy: rather than putting a single measurement front and center, it focuses on the trend and invites you to observe how different factors (health metrics, behaviour) actually move it. The update will be available on the App Store from 30th of March on.
Cardio Fitness in Gentler Streak
VO₂ max measures how efficiently the body uses oxygen during exercise. Beyond workouts, it affects our everyday energy and long-term resilience - research consistently links higher cardio fitness with reduced risk of heart disease, type 2 diabetes, and premature mortality.
Apple Watch estimates cardio fitness from recorded outdoor runs, hikes and walks, using heart rate, motion, barometric, and GPS sensors. Gentler Streak now reads this data from Apple Health and presents it in a way designed to be meaningful rather than just throwing the last recorded stat at you.
App Store ETA: 30th March 2026
Version: 5.12
Key features:
Cardio Fitness lives in the Wellbeing section of the Streak tab, alongside existing health metrics
On the main card, you’ll see gentle heart animation reflecting the current state of your VO₂ max estimate and its state
A trend state - increasing, stable, or declining - with a brief contextual explanation
Monthly averages plotted across a yearly scale, with an overall year average. Tap any point to see that month's average and range. The further back your Health app data goes, the further back you can explore
Spot the pattern - Resting Heart Rate, Steps, Activity Duration, Energy, and Distance sit below the chart as tappable bubbles. Switch between them to see how each one moves alongside your VO₂ max over time, and if you can notice any correlations
Info screen:
Contextual brackets showing how your estimate compares to averages for your age and sex group
Clear explanation on what affects the accuracy of the estimate: sport type, watch usage, outdoor session frequency
"We deliberately chose not to make the number the hero here. A single VO₂ max figure from a consumer device can't tell you much, and in a lot of cases, it wouldn't even be accurate. However, what does tell a story is the trend: where it's heading, and what seems to be driving it. Over time, you might start noticing patterns between your behaviour and your cardio fitness, and that’s where you can learn." Katarina Lotrič, Gentler Stories Co-founder and CEO.
About the VO₂ max Estimate
The estimate is most accurate for those who run regularly - that's the movement pattern the algorithm is calibrated to. Because of this, walkers can see a higher number than their actual running fitness would support, and when they start running, the figure often drops to a more accurate level. Those active mainly in other sports, cycling, swimming, gym training, may see a lower number than their cardiovascular fitness actually reflects. And it will always vary from a supervised lab test, which remains the only clinically validated measurement. But what it does well is track change over time, and that's what Gentler Streak uses it for.
A Note From the Team
In our experience, people can take what wellness/fitness apps say more literally than is healthy, and we’d like to address that. Health and fitness data does its most honest work when it informs and leaves some room for interpretation - not when it makes absolute statements, tricks you into engagement, or creates pressure where there shouldn't be any.
No app, including ours, can know your context, your actual stress, your health/body predispositions. The best, most accurate source of information on how someone truly feels is the person themselves. We, as a society, need to acknowledge and accept that commercial devices cannot and don't substitute ourselves, our doctors, or any professional that works one on one with us. Apps can in the best cases serve as lighthouses - if they are built on quality data, interpreted with enough humility, and with an agenda to actually support you where you are. Investor-backed apps rarely have that freedom, as they are optimized for growth. We'd call for critical thinking when deciding which apps to let into your life, why, and to what extent. Read the privacy policy. Understand the business model. Ask yourself whether the app is designed for your benefit, or mostly for its owners. We built Gentler Streak's wellbeing section to help notice changes in the body faster, understand cause and effect better, and take more informed decisions. Not to replace judgement, not to outsource decisions that are ultimately yours, but to inform them.
