Faster 10k has a lower vo2max compared to slower 10k?

MeanGreen

Can anyone clarify why these similar 10k runs have such different effective vo2max values?
I assumed faster pace meant higher vo2max, but there seems to be something I'm missing. Is it because of the heart rates in relation to the pace?

Run #1:
Duration: 57:48
Pace: 5:47/km
Elevation: 73m
Energy: 576 kcal
Avg heart rate: 82%
Max heart rate: 89%
Effective vo2max: 37.94

Run #2:
Duration: 59:25
Pace: 5:57/km
Elevation: 48m
Energy: 542 kcal
Avg heart rate: 76%
Max heart rate: 81%
Effective vo2max: 40.90

Edit: When I ask ChatGPT to calculate the estimated vo2max based on these runs, the results are 41,91 and 40.85, which is a lot closer to what I'd expect.

Laufhannes

The following help article should clarify this: https://runalyze.com/help/article/difference-between-vo2max-and-effective-vo2max

Have a look at the avg. heart rate. The first run is slightly faster but has a much higher avg. heart rate. The Effective VO2ma is based on an extrapolation what pace you can run in a race assuming some fixed 'race heart rate' (for a given distance).