Originally Posted by
RChung
Right, there's a split between the demand and supply sides of power, and that has consequences for measurement. There are lots of different things you can do with a power meter and they differ in the degree of accuracy and precision they require. As a rough rule of thumb, the things you do on the supply side have fewer requirements for accuracy and precision than the things you do on the demand side, which is why many people can train (especially FTP) pretty effectively with a HRM, a wristwatch and a course of known distance, or even a one-sided power meter. FTP is sorta more an organizing principle than a bright shiny line.
I give regular formal tests to students but in my own work I don't take tests to figure out whether I'm making progress. Hmmm. Maybe I should.
Exactly. All of these things we use to describe effort- power, heart rate, RPE and resp rate/quality- have their own degree of wiggle to them & are affected by different things.
I'm sure people approach things variably, but for me I race a TT monitoring those four factors constantly. Sometimes you have to throw one or two out the window, they will be off to an unpredictable degree. A great example is when I raced at Loyalton last year and discovered a different physiologic effect on me doing a 100% effort at 5000 ft. I train at 1200 ft and have ridden a decent amt at altitudes ranging up to 11,000 ft. I thoughtI had a good idea of the effect of altitude on my power output but what I failed to realize is that the effect as I understood it was for endurance events. Turns out I experience a much greater effect at a 100% effort than at a 75% effort.
So I floundered a bit and tried to fall back on HR but that was off too in ways I hadn't previously experienced. I should have just fallen back on RPE, that was a great lesson there.
Which is part of my point, you really have to just go out and do some of these things in order to understand the effects. Ideal conditions are great but since you don't always have them, there's something to be said for exposing yourself to less-than-ideal conditions too. By way of learning over time.
Totally different thing than the objective output data you might get using a power meter for aero testing say.