Discussion: Intensity

I feel like intensity, being a subjective measure, changes under circumstance. Being already tired, pushing hard anyway but only mustering a speed which would normally constitute intensity 3 could be a 4 or more if you were intense about trying.

I'll stipulate that perceived effort isn't an objective measure but I want to correlate with the level of output from and stess on my cardiovascular system rather than with the willpower required to persevere since I think it's the former that determines the resulting physical training effect (no comment on the willpower training effect, though perhaps that's also something I ought to focus on).

Another way of saying what I intended is that with an already stressed cardiovascular system you can be working it as hard as you would during intensity 4 and still end up with a non-stressed intensity 3 pace. Lacking the portable heart and lung monitoring hardware, perceived pushing, and race splits are what you have left to go by.

Maybe I'm wrong on the physiology but that doesn't sound right to me in the context of what I perceive as the primary reason to keep track of my training. To take an extreme illustrative example, I don't think I would get the same training effect by running intervals slowly while sick as I do by running them at my usual pace while fresh and healthy no matter how identically difficult the effort felt. Though if I viewed my log as primarily a tracking tool to help me avoid overtraining, I probably would just go with my perceptions.