analisi dislivello su traccia gpx

Do you mean the accumulated ascent or just the difference in elevation between two points? If you just want the difference in elevation you can just subtract the values. The accumulated ascent would be very interesting and is not easy to calculate on your own.

Ascesa accumulata. I dati dovrebbero essere disponibili nella traccia gpx ma non sono mai visibili …

In the GPX there is only data for the position and elevation. Nothing accumulated so everything must be calculated from those logged points.

Nice!

To do that with a logged activity you can view the activity in Garmin Connect Web and click "Save to My Courses". The course will open up and you can select the elevation profile. You don't have to save the course. This is just a method to quickly view the accumulated ascent.

Yes, either that, or you could also use the function Trim Activity, and trim it to the section of interest. Since the trimming is reversible, you can repeat it as many times as needed, with different selections. For a single selection it may be quicker, but otherwise using the option Save as Course, is usually more comfortable

... I should also note, that the Elevation Gain of an activity will be typically much higher that the estimated Total Ascent of a course. That's because of the difference of resolutions between those two - while the course has usually a few tens or hundreds of track points, the activity has typically thousands of them. For a more detailed explanation of the effect, look up the term "Coastline Paradox"

Grande!!! Questo è una bella soluzione.