Wednesday, September 12, 2007

Tracking Functional Power

Functional Threshold Power (FTP) is the highest average power you can hold for a 1 hour steady effort. I performed a 1-hour road test for FTP in December 2006 and found it to be 240 watts. I tried again in April and got a result of 268 watts. My next sheduled test was August, but when I attempted the test, I couldn't get through it mentally - I stopped after 20 minutes. I guess it was just one of those days.

The difficulty of accurately measuring FTP on any given day got me thinking. I compared my FTP testing results with my 60-minute best normalized power (NP) for the same period and saw a very strong correlation. So I think I might make the formal FTP test a thing of the past and just monitor my 60 min NP to determin my FTP - it seems to be just as good or better of an indicator that one test on a single day and it uses data from hard training and racing, requiring no training-to-racing conversion factors. (With FTP testing in training, I always threw in a 1.03 factor to account for motivation of racing, etc., and I'm always a little wary of generic factors). So from now on I'll use racing data and keep the factors out of it.

FTP is a good indicator of road racing and TT fitness, but to get a better handle on my crit fitness, I'll also track what I'll call CTP, or Crit Threshold Power. It's nothing more then mean maximal 35-minute NP. It includes more of the anaerobic effort required for short crit races like we see in cat4 races, so it might not track exactly with FTP throughout a season.

As you can see below, my FTP climbed over the winter and early spring, levelling out at about 275 watts, which I think is accurate. My CTP pretty much mirrored FTP except for a jump in the last month, which I attribute to the sprint training I've started to do. I look forward to see where that goes with more work.

One last caveat: in order for this chart to accurately reflect my fitness, I need to make sure to do at least one or two hard 35-minute and 1-hour efforts in each two month period, even during the winter. Do crits exist in January?