Tuesday, April 03, 2007

Normalized Power

Since I've paid attention to normalized power (equivalent constant power output), I've been a little skeptical that it is a really accurate way to equate a very inconsistent power output (out of the saddle accelerations followed by back of the pack coasting then a 10-minute paceline chase) to a constant power output during that same period.

But the last two times I've been dropped (on Pate Road a couple of weeks ago on a Tuesday Macon ride, then Saturday on the dirt road in the Perry RR), I had been riding for more than an hour at an intensity factor (IF)of about 0.97-0.98. That means both efforts were equivalent to 97 or 98% of my functional threshold power (FTP) for over an hour. FTP is the maximum average wattage one can hold for a one hour flat TT.

That tells me that I have calculated my FTP accurately (about 245 watts) and that the normalized power routine, which uses a long algorithem with powers of 4 in it, does a good job of measuring riding intensity.

I'd like to keep improving so that I rarely get dropped, but at least if I do pop off the back I can look at my IF to see if I gave it 100% or if I just gave up.