Friday, June 20, 2008

PowerCrank Preliminaries

I’ve been selected for Frank Day’s PowerCrank study, and honestly I do hope I get some benefit from the use of PCs. The proof will be in the power numbers that come after adaptation to the cranks, and fortunately I have much historical data from the last 5 years to make a solid comparison point. It should be noted that my typical volume of cycling is in the 500-650 hour/year range. Living in a moderate climate (Houston, Texas), I am able to cycle year round and maintain at least a certain level of fitness. Dips in fitness are usually only associated with illness, injury, or travel for work. My FTP is also affected in the summer months by the intense heat and humidity in the Houston area. Nonetheless, at 39 years young and 66-68 kg for summer form, my road position usually nets a FTP in the 265-275 W range. On the TT bike I suffer a slight decrease in performance on the order of 10 W or so. I’m a classical time trialist – weak in neuromuscular power. If you look at my 5s and 1m powers on Andy Coggan’s power profiling charts, you’ll see that they are 8-10 lines below my 5 and 60 minute powers.

To look for positive trends from PCs, I will throw out a couple of the low points in the data. There were some definite periods where the month was comprised of only a couple of rides (due to illness or travel). The periods thrown out are June and July 2004 (was going to Japan or Europe almost every other week) and September and October 2005 (was in Japan almost all of Sept without a bike, and October was like getting on the bike all over again).

To look for positive trends, I’ve taken the above data and averaged it across a yearly basis by month. So the May month is an average of the Mays from 2004 to 2008. The plots below show the average (thick black line) and 1-sigma, 2-sigma, and 3-sigma lines for the reported data. If PCs work, I expect my numbers to be above the 2-sigma line (thick yellow line). That would mark a small improvement in FTP, but after years of training where I feel I’ve reached a limit on FTP, even a 10 W gain would be significant (translating to 30-60 seconds quicker in a 40k).