What is the meaning?

I believe it's your 5k run estimate. 3.1 is that distance in miles. 8:13 is your pace in minutes per kilometer and 41:04 mins is your estimated finish time. All related to your vo2 max recording. This may be incorrect, so someone please step in a help if anyone is positive on this. I'm just guessing.

Thank you for your reply. I don't understand because I didn't run since I have the watch, only walked with. Not understand too the 3.1 in miles because I customized my watch in kilometers.

Very strange...

Which watch face and is this a Fenix 6?

Is the standard from Fenix 7X solar.

OK, I'll move this thread to the fenix 7 forum.

If you press and hold the data you should be taken to the screen that has more detail on this

Ok, I succeeded! Thank you to Diggs.

In fact it's easy when you know, just to press and hold the finger on the screen on the field you want and the magic operates, you get a complete report about the field chosen. 

Working for all fields on screen.

Not sure that is well explained in the Garmin doc.

you're welcome, it only works on Garmin faces at the moment but I find it very useful