Originally Posted by wphamilton

That could be difficult to compare because our response to training depends on our level of fitness relative to our potential. It follows an "S" curve, like many things biological. After a certain point it tapers off, with diminishing returns. So I think you'd have to be somewhere in the middle linear portion, trying it either way for awhile. Maybe, a lot of cyclists start out training with perceived effort, then buy a power meter and use that, and have kept good enough records to compare. I haven't seen anything like that posted though.

What I do find curious though, and it plays to your point, is that runners hardly ever use devices to measure power. They rely on pace - speed - as a proxy and utilize that almost exactly analogously as you'd use power measurements. Obviously speeds are lower and wind drag less of a factor, and yet ... it's not insignificant either. To put real numbers to it, somewhere around 8 to 8:30 pace you start to lose time outside vs a treadmill, which is (primarily) due to wind resistance. There is a lot of "sloppy" opinion about that out there, but let me just say that best information is that pace is non-linear with power for practical purposes for runners at around an 8 minute pace. Which is pretty slow, generally speaking.

So to me, it shows a logical discrepancy in approach, two different "conventional wisdoms" in the two sports even though the physiological objectives and physical factors are largely similar. If pace is "close enough" for competitive runners, why isn't speed "close enough" for competitive cyclists, as you contend?