From where do you got that screenshot? It doesn’t look like Strava and it’s difficult to read too.

Hi Jan, I attach here below the screenshot from Strava. Previous was from Garmin. Could you check where the record on 1 km is ? Just curious.

Furthermore could you explain me what are the data on Y-axis on the below right graph? (0 m, 5 m, etc.) ? thanks for your help

These are laps. I guess you ran a planned workout that created a lap for every workout step, therefore the many short laps in the middle of the activity. From the lap times I would guess the 1 km best began in the 20th lap and ended in the 21th lap.

The y axis with the 0m or 5 m is the current elevation.

It is almost impossible to identify exactly where the “best 1km” would be from that.  It is not going to fit exactly to a specific “lap”, it is going to be just some 1km portion of the entire workout.  It very likely could include a bunch of your short 0.08km intervals combined, but likely starting partway into one and ending partway into another.  

Hi Jan, thanks for your reply. Just another question, I understand the grey area represents the current elevation, but what are the blue and red lines? 

Hi anchskier, thanks for your reply. Do you mean the portion of the entire workout is made of continuous intervals, correct? I want to say that the intervals to be taken into account for the record must be in sequence and not taken random “here and there” just for reaching 1 km. Correct?

;-) Thanks to all, cheers!

The blue line is the pace and the red line your heart rate. You can see details when moving the mouse over the graphs: 

The intervall for the personal best is always a continuous part of the activity. The intervalls that are representing the 22 laps in your screenshot don’t matter in this regard.

Thank you so much for the reply. Now It’s clear.

Ciao