the app hasn't been recording VO2 Max...how do I reinitiate that measurement?

Possible Solutions for Vo2Max

1.Tighten the watch band a touch and clean the sensors on the bottom of the watch..

2.Reset fitness calibration.

3.Input a VO2 max figure manually based off your last record from the health app then re-calibrate the watch.

4.Put the watch in airplane mode,do a walking/running or hiking workout of at least 20 minutes,when you've finished turn airplane mode off and let the watch sync the data to the phone.