Estimated Sweat Loss - FENIX 6

No, not currently. There are many analytic based information that is either only available once the activity is done and saved, or only available after Garmin Connect has done it's magic based on the activity uploaded.

If you take a look at the attributes available in the Class Info it will give a guidance of what's available directly or what you (or someone else) can use for analytics to create a new field:

https://developer.garmin.com/downloads/connect-iq/monkey-c/doc/Toybox/Activity/Info.html

I don't have a 6 only 5, however sweat loss is one of the key points for me. Does the "sweat loss" calculate the loss during the activity and post activity?

I think only during activity.

Thank you for reply. So we can wait, maybe it will be in next updates :-)

I don't ha a 6 only a 5, however sweat loss is one of the key points for me. Does the sweat loss only calculates the loss during the activity or also post activity?

Depending on the type of activity and if you drink or not during the activity there may be easier and probable more reliable ways to get the sweat loss (or dehydration). Take your weight before and after (without clothes) and check the difference. The loss in weight is almost only because of sweat. I do this once in a while for running, cycling or gym activities where I don't drink during the activity and I know that I didn't take a leak :-)

That gives me a guidance based on time, intensity and weather conditions that I can use for other activities.