I’ve always just used the hrTSS value that Training Peaks calculates from my heart rate (via a Garmin watch and HR strap) and the duration of the workout. It usually seems to be a reasonable number. As a reference point: When I cross train with cycling the TSS number TP calculates from my measured cycling power matches pretty close (usually within 10%) to the hrTSS it also calculates which makes me think it’s a reasonable approach. You do have to have your HR zones set correctly in TP.
I think Training Peaks TSS is based on pace and duration of running on a flat course? Using a TSS based on duration and pace and then adding in fudge factor for elevation gain and another for how ‘difficult’ the snow and maybe another for pack weight just seems much less accurate???
Thoughts?
Ron