True VO2 Max gives you lab-like cardio fitness insights using your Apple Watch — now indoors too.
Stop getting misleading VO₂ max drops from heat, humidity, altitude, smog, or tough outdoor conditions. We correct for real-world factors so you can trust your fitness trend. And with our first-of-its-kind Indoor Treadmill VO₂ Max, you can track cardio fitness even when you run inside.
No account required.
No ads.
▷ INDOOR TREADMILL VO₂ MAX
- Estimate VO₂ max from indoor treadmill runs
- Perfect for winter, rain, or night runs
- See indoor fitness changes clearly — without outdoor weather noise
▷ CORRECTED VO₂, ANY WEATHER
- Removes temperature, humidity, altitude, heat, cold, etc.
- Raw vs Corrected shown side-by-side
- Trust the trend, not the temperature
▷ SCIENCE-BACKED CORRECTIONS
- Research-based penalties for weather & elevation
- Transparent impact per condition
- Spot real changes vs. bad weather
▷ IMPACT RESULTS
- Automatic processing the moment you finish your workout
- Be first to see your real fitness trend — no more confusion
- See progress even when conditions make it look worse
▷ AUTOMATIONS
- Apple Watch sync
- Health app sync
- VO2 corrections, no manual input needed
▷ WHAT'S FREE?
- No ads
- Unlimited runs/workouts
- Corrected VO₂ max vs. weather
- Raw Apple Watch VO₂ max vs. Corrected VO₂ max
- Weather logging
- Record your activities
- Basic insights about your performance
▷ WHAT'S PLUS?
- Indoor Treadmill Watch app
- Instant weather capture as soon as you finish your workout
- Most accurate VO2 max correction every time
- Clear & transparent impact per weather condition
- Improve your VO₂ max with Full Insights
- Personalized performance takeaways
- And more
Try Plus free for 7 days. Cancel anytime.
▷ PRIVACY
- No account needed
- No tracking
- No ads
- No personal data collected
- No third-party SDKs
- All logged info (runs, corrected VO2 max, etc.) remains on-device
Not a medical device. True VO2 Max is for fitness and wellness only.
Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
I love the app when it works, but I often have trouble with it not reading recent outdoor runs or walks where there is indeed a VO2Max score. I use the same tracking method, Apple Watch Series 11, iPhone 17 Pro Max, tracked with the Fitness app every single time. Currently it only shows runs through early last week when I have had 3 outdoor runs since then. There is no refresh button, all permissions are granted, no changes made.
Developer Response
Hi Mark, thank you for the feedback! We just completely rebuilt workout syncing in our latest update to make importing runs and walks from Apple Health and the Fitness app faster and more reliable. If you still experience any issues, please email us directly at truevo2max@gmail.com and we will happily jump in to help!
Love the app!
Mark605@605
It’s amazing that it factors in elevation and temperature during the run. Easy to use and set up!
Not great
USA-DK
The app doesn’t see indoor workouts even with a paid membership, it’s simple won’t take into account count your treadmill runs. This app should be free until everything is fixed and works as advertised.
Developer Response
Hi there, thank you for your feedback, and I am very sorry for the frustration. I want to sort this out as soon as possible for you. To track your treadmill runs correctly, please ensure the True VO2 Max app is installed directly on your Apple Watch. You will need to use our watch app to record your treadmill sessions instead of the native Apple Fitness app. If you are already doing this and it still is not working, please email us at truevo2max@gmail.com. To help us troubleshoot, please include your iPhone and Apple Watch models, along with screenshots of the Indoor Settings tab from the True VO2 Max app on your phone. We want to get this fixed for you right away.
Not sure what this does
Littlewing745
I’d love to try it, the concept sounds great. However…it doesn’t pull any data whatsoever. I’ve uninstalled, reinstalled, quadruple checked permissions. It simply doesn’t work.
Developer Response
I’m sorry it didn’t work for you. Please note that True VO2 Max only pulls outdoor runs recorded after the app is installed, and it initially relies on Apple Health’s Cardio Fitness (VO₂ max) value for each run. If Apple Health didn’t record VO₂ for that workout, there’s nothing for the app to normalize and display.Please confirm VO₂ exists in Health → Cardio Fitness → Show All Data at the time of your run. If it’s missing, updating to the latest watchOS commonly resolves the Apple Watch→Health VO₂ sync issue. Then do a new outdoor run long enough for a VO₂ estimate (e.g 10 mins), and verify Health → Cardio Fitness → Data Sources & Access has the True VO2 Max app enabled to read data and your Watch listed as a data source. If you’d like, email truevo2max@gmail.com and I’ll troubleshoot with you.
Completely rebuilt workout syncing for faster, more reliable updates from Apple Health.
Workouts now appear sooner while additional details continue syncing automatically.
Improved post-workout summaries, including clearer handling of information that is still processing or unavailable.
More reliable route, weather, heart-rate, and VO₂ max enrichment.
Post-workout notifications are now available to everyone.
Improved subscription purchasing and entitlement recognition.
Safer workout-history migration, stronger data protection, and numerous performance and stability improvements.
Stay tuned & rate us if you enjoy using True VO2 Max!
Version 2.5
The developer, DANIEL BLACKBURN, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Privacy practices may vary, for example, based on the features you use or your age. Learn More
The developer indicated that this app supports the following accessibility features. Learn More
Supported Features
Dark Interface
Differentiate Without Color Alone
Sufficient Contrast
Information
Seller
DANIEL BLACKBURN
Size
44.7 MB
Category
Health & Fitness
Compatibility
Requires iOS 17.6 or later.
iPhone Requires iOS 17.6 or later.
Mac Requires macOS 14.6 or later and a Mac with Apple M1 chip or later.