Power Meters / Powermeters (SRM, Powertap, Quarq, Ergomo, Vector, Stages, power2max, P2M, 4iii, InPower, Cinch)

I've walked for two hours today at a fair clip, if I was being totally anal it would be an idea to input that as it would affect the PMC.

Does it add anything to fitness though?

I don't add TSS for anything but cycling as it doesn't add fitness and thus would mess up CTL. Nor does it necessarily affect cycling performance.

Personally I make a note in my diary of what I did but don't add TSS. So if I look back at past workouts I can see that if I sucked for a reason I can see in the diary that a 4h walk might not be a good idea.