Noob Question

Can you tell me what these numbers mean? (I have difficulty believing this is not on the page somewhere or in a popup. Must be too trivial)

Recommended XSS : 259 ( 228 | 25.6 | 5.3 )

I assume 259 = XSS what are the others?

It’s the low (TP), high (HIE) and peak (PP) parts of the XSS that’s recommended. Seems a bit high overall to me for one workout though.
And this info is pretty new so maybe not documented as well as it’s going to be yet.

The numbers are the breakdown of low/high/peak strain.
XSS (strain score) is similar to TSS (stress score) but not the same.

Thanks. (It was a 60 mile ride)

All activities (indoor/outdoor) are also classified by Difficulty, Specificity, and Focus.
Difficulty Rating: Easy, Moderate, Difficult, Tough, Hard
Specificity: Polar, Mixed, Pure
Focus Duration: 2 min (Road Sprinter), 3 min (Pursuiter), 4 min (Puncheur), 5 min (Breakaway Specialist), 6 min (Rouleur), 8 min (GC Specialist), 10 min (Climber), 20+ minutes (Endurance: Sprint TT thru Triathlete)