VO2 max very low in new watch

Apple says:

To estimate your cardio fitness level, your Apple Watch also takes into account your:

• • Age
  • Sex
  • Weight
  • Height
  • Medications that might affect your heart rate

It can take at least 24 hours of wearing your Apple Watch, followed by several workouts* and passive measurements with your Apple Watch before you receive an initial estimate.

First, notice the word estimate in the description. To measure VO2 max, a statement of lung capacity and oxygenation efficiency, you would need to be wearing a mask and measuring the flow of air into your lungs. The Apple watch uses information you give it, and data it measures, to guess at your VO2 max.

So, have you entered that information?

Use the Health app on your iPhone or iPod touch - Apple Support

Have you calibrated your watch?

Calibrate your Apple Watch for improved Workout and Activity accuracy - Apple Support

See more here:

Track your cardio fitness levels - Apple Support

Huh? You are in a discussion group of users like yourself. Telling us what to do will not help you.

You apparently have talked to Apple. You refer to Apple's response, but you do not tell us what Apple said.

Try giving feedback to Apple:

Feedback - Watch - Apple

An example of a cracked wheel tapper’s hammer! My two previous watches have much higher levels. ‘New watch’ low readings.

Apple’s response, it’s the human’s problem.

no, it’s Apple’s software at fault. Fix it Apple. Your software is broken!