Where to Find VO2 Max on iPhone
Open the Health app, tap Browse, then Heart, then Cardio Fitness. Apple calls VO2 max Cardio Fitness, and it only appears after an Apple Watch Series 3 or later has recorded outdoor walks, runs or hikes.
How do you find VO2 max in the Health app?
It is under Heart, labeled Cardio Fitness, not VO2 max.
- Open the Health app on your iPhone.
- Tap Browse at the bottom of the screen.
- Tap Heart, then tap Cardio Fitness.
- Tap D, W, M, 6M or Y to see daily, weekly, monthly, six-month or yearly averages.
- Tap Show All Cardio Fitness Levels, then a level, to compare your number with others your age and sex.
On iPad, tap the sidebar button instead of Browse. To skip the menus, type Cardio Fitness into the search field at the top of Browse. The unit is mL/kg/min, and Apple reports values from 14 to 65.
Which Apple Watch measures VO2 max?
Apple Watch Series 3 or later. iPhone cannot estimate VO2 max by itself, because the reading comes from the watch's heart rate and motion sensors during outdoor workouts. Apple shows a level (Low, Below Average, Above Average or High) for people aged 20 and older.
Which workouts count toward a VO2 max reading?
Outdoor Walk, Outdoor Run and Hiking in the Workout app. Indoor workouts, including treadmills and gym equipment, do not count, and wheelchair Push workouts are not supported. Apple's white paper lists what a workout needs to produce an estimate:
- Fairly flat ground, under a 5 percent incline or decline.
- A good GPS signal and a clean heart rate reading.
- Enough effort to raise your heart rate about 30 percent of the way from resting to maximum. A brisk walk is often enough; you do not need an all-out run.
Apple also counts passive measurements, so everyday outdoor walking adds to the estimate between workouts.
Why doesn't VO2 max show on my iPhone yet?
Most often the watch simply has not collected enough qualifying data. Apple says the first estimate needs at least 24 hours of wear, followed by several outdoor walks, runs or hikes, and the very first qualifying workout never produces one. In Apple's validation study, over 90 percent of people with at least one outdoor walk, run or hike longer than three minutes received an estimate.
If you have done those workouts and still see nothing, check these:
- Your age, sex, height and weight are filled in under Health Details. Apple uses them, along with any heart rate medications, in the estimate.
- Your workouts were the outdoor types, not Indoor Walk or Indoor Run.
If Health later finds your older estimates could be more accurate, an Update option appears on the Cardio Fitness screen under Update Your Data, and a notification shows how the numbers changed.
How do you get notified about low cardio fitness?
On iPhone, open the Apple Watch app, tap My Watch, then Apps, then Heart, and turn on Cardio Fitness Notifications. You are notified when your level is Low for your age and sex, and about every four months if it stays low. If you take a medication that limits heart rate, such as a beta blocker, add it in Health Details: in Apple's testing that cut the average error for those users from 11.8 to 1.6 mL/kg/min.
To see what your number means for your age, use the VO2 max chart by age and sex.
How VO2 Max helps
VO2 Max & Cardio Fitness reads the same Cardio Fitness estimate from Apple Health, read-only, and shows it without the menus: the latest value with its date, the trend, home and lock screen widgets, and an Apple Watch app.
See your VO2 max without digging through Health
Free on iPhone and Apple Watch. Read-only access to Apple Health, no account.
About VO2 Max & Cardio FitnessFrequently asked questions
Where is VO2 max on iPhone?
In the Health app. Tap Browse, then Heart, then Cardio Fitness. Apple calls VO2 max Cardio Fitness, so searching Health for VO2 max may not find it; search Cardio Fitness instead.
Can iPhone measure VO2 max without an Apple Watch?
No. The estimate comes from an Apple Watch Series 3 or later during outdoor walks, runs and hikes. An iPhone alone records steps and distance but not Cardio Fitness.
Why does my iPhone not show VO2 max?
Usually because the watch has not recorded a qualifying workout yet. You need at least a day of wearing the watch and several Outdoor Walk, Outdoor Run or Hiking workouts on fairly flat ground with GPS. Indoor and treadmill workouts never count, and your first qualifying workout does not produce a reading.
How long does Apple Watch take to show VO2 max?
At least 24 hours of wear followed by several outdoor walks, runs or hikes, according to Apple. In Apple's validation study, over 90 percent of people with at least one outdoor walk, run or hike longer than three minutes got an estimate.
How do I turn on low cardio fitness notifications?
On iPhone, open the Apple Watch app, tap My Watch, then Apps, then Heart, and turn on Cardio Fitness Notifications. You get one when your level is Low for your age and sex, then about every four months if it stays low.
Sources
- Apple Support: Track your cardio fitness levels
- Apple Watch User Guide: Monitor your heart health
- Apple: Using Apple Watch to Estimate Cardio Fitness with VO2 max (white paper, May 2021)
This page is general fitness information, not medical advice. VO2 max estimates are approximations, and the app does not diagnose, treat, cure or prevent any condition. Talk to a clinician about your health.