![Why does the watch measure vo2max on random days when i workout almost every for 20+mins? And how is it so bad on good workouts and good on bad workouts? : r/AppleWatchFitness Why does the watch measure vo2max on random days when i workout almost every for 20+mins? And how is it so bad on good workouts and good on bad workouts? : r/AppleWatchFitness](https://preview.redd.it/why-does-the-watch-measure-vo2max-on-random-days-when-i-v0-dumb129gmuc81.jpg?width=640&crop=smart&auto=webp&s=90f87d6e18b623f28140d4df12d54eaa2bed7bbc)
Why does the watch measure vo2max on random days when i workout almost every for 20+mins? And how is it so bad on good workouts and good on bad workouts? : r/AppleWatchFitness
![How exactly is VO2 max on Watch calculated? I don't think it actually measures oxygen, does it? Today I let my friend wear my watch to test and she had the same How exactly is VO2 max on Watch calculated? I don't think it actually measures oxygen, does it? Today I let my friend wear my watch to test and she had the same](https://preview.redd.it/how-exactly-is-vo2-max-on-watch-calculated-i-dont-think-it-v0-809a297xuzbb1.jpg?auto=webp&s=5d3fec17d59ddd6b42d955c08603633876df739e)
How exactly is VO2 max on Watch calculated? I don't think it actually measures oxygen, does it? Today I let my friend wear my watch to test and she had the same
![VO2 max displayed in Apple Health (a) and Garmin Apps (b). This data is... | Download Scientific Diagram VO2 max displayed in Apple Health (a) and Garmin Apps (b). This data is... | Download Scientific Diagram](https://www.researchgate.net/publication/360957487/figure/fig5/AS:1182642905063448@1658975449848/VO2-max-displayed-in-Apple-Health-a-and-Garmin-Apps-b-This-data-is-calculated-in-the.png)
VO2 max displayed in Apple Health (a) and Garmin Apps (b). This data is... | Download Scientific Diagram
![Sudden drop or change in cardio fitness score (VO2 max) on your Apple Watch and iPhone Health app? - MyHealthyApple Sudden drop or change in cardio fitness score (VO2 max) on your Apple Watch and iPhone Health app? - MyHealthyApple](https://www.myhealthyapple.com/wp-content/uploads/Health-app-iPhone-Sudden-drop-in-Apple-Watch-cardio-fitness-score.jpg)