VO2Stats Developed by Bramhand Inc.
VO2Stats is a personal wellness and fitness tool. It is not a medical device and does not provide medical advice, diagnosis, or treatment recommendations.
Always consult a qualified healthcare provider before starting or changing an exercise routine, especially if you have a medical condition.
If you have a question, found a bug, or have a feature request, we’d love to hear from you.
Send an email to:
app AT bramhand DOT com
Please include:
We aim to respond within 2 business days.
Is an account required? No. VO2Stats has no sign-in of any kind. There is no login, password, or registration — everything runs on your device.
Where is my data stored? All estimates are computed and stored locally on your iPhone. Nothing is sent to any server.
Why does VO2Stats request access to Apple Health? VO2Stats requests read-only access to your workouts, heart rate, resting heart rate, walking/running distance, active energy, step count, body weight, height, cardio fitness (VO₂ max), biological sex, and date of birth. It uses these to calculate VO₂ max estimates. VO2Stats never writes anything back to Apple Health. You can manage these permissions any time in the Health app under Sharing → Apps → VO2Stats (or in iPhone Settings → Privacy & Security → Health → VO2Stats).
Why do I see several different VO₂ max numbers? VO2Stats estimates your VO₂ max with multiple scientific methods at once — each uses different inputs (resting and maximum heart rate, running pace, a walk test, heart rate recovery, or a non-exercise estimate). Because their assumptions differ, they rarely agree exactly. Seeing the range across methods is the point: it gives you a fuller picture than any single number.
Why is VO2Stats’ number different from the VO₂ max in Apple Health? Apple Health shows a single value from Apple’s own algorithm. VO2Stats uses several independent, published methods and shows them side by side — including Apple’s value for comparison. Different formulas produce different numbers for the same person; that is expected.
Some methods show no estimate — why? Each method needs specific data. A running-pace method needs recorded outdoor runs; a walk-test method needs a suitable walk; heart-rate-recovery needs workouts with post-exercise heart rate. If the required data isn’t in Apple Health yet, that method stays empty until you record the relevant activity.
Does VO2Stats need the internet? No. All calculations run entirely on-device. VO2Stats has no backend and transmits no data.
Does VO2Stats cost anything? VO2Stats is a one-time paid purchase — you pay once and own the app. There is no subscription, no recurring charge, no in-app purchases, and no ads.
Can I transfer my data to a new iPhone? Your estimates are recomputed from the Apple Health data on your device, so once your new iPhone has your Health history (for example, restored from an iCloud backup), VO2Stats will show your estimates again.
VO2Stats calculates VO₂ max using nine established, peer-reviewed approaches:
Each method’s formula, its scientific reference, and its limitations are shown in the app under the Methods Guide tab. These sources are provided for transparency and are not personalized medical recommendations — VO2Stats is not a medical device.
Two representative references:
The complete list of references, with direct links, is available in the app’s Methods Guide.
Last updated: July 2026 Bramhand Inc.