Cardio Fitness VO2 does not update no matter what I do

Hi there

Please try this

1. Add a Manual Baseline Data Point

• • Open the Health app on your iPhone.
  • Go to Browse > Heart > Cardio Fitness.
  • Tap the + (Add Data) button in the top right corner and manually log a reasonable VO2 max estimate for today.
  • Follow this up the next day with a dedicated, flat outdoor walk or run using the Apple Watch Workout app for at least 20 minutes. Forcing a manual entry can sometimes jumpstart a stuck calculation pipeline. 

1. Verify GPS and Location Services for Workouts

• • On your iPhone, go to Settings > Privacy & Security > Location Services.
  • Scroll down to Apple Watch Workout (and System Services) and ensure Precise Location is turned On.
  • Make sure that during your outdoor walks/runs, your iPhone is either with you or the watch's GPS is actively getting a clean fix (avoid heavy tree cover or dense concrete canyons that mess with pace data).

1. Check Heart Rate and Motion Permissions

• • On your iPhone, open Settings > Privacy & Security > Health.
  • Tap Apple Watch and verify every single toggle is green—especially Cardio Fitness, Heart Rate, and Fitness Tracking.
  • On your Apple Watch, go to Settings > Privacy & Security > Motion & Fitness and make sure both Fitness Tracking and Heart Rate are toggled On. 

Have you checked that your pulse (heart rate) is measured and showing on the watch throughout the workout?

I mention this because I have found with outdoors walking and cycling workouts, if I don't tighten the watch band by one notch, sometimes the heart rate stops recording. Bicycling goes over bumps in the road and even walking has a fair amount of arm and watch motion. This apparently can occur when one is active enough that the watch is jiggling enough during the workout and thus unable to get a persistent and reliable heart rate sensor measurement on the arm/wrist. There are many reasons why this can work at some time in the past and then stop, but have you checked that the watch band is snug and tight and that the sensor is centered on the arm and far enough away from the wrist/hand so that a reliable heart rate reading is obtained throughout the entire workout?

If the heart rate measurement is not continuous or is interrupted, the cardio fitness might not update.

Cardio Fitness only updates from outdoor walk, run or hike workouts with a good heart rate reading. Make sure Location Services and Motion & Fitness are on for Workout, and that your age, weight and height in Health > Profile are correct.