Bike Functional Threshold Power (FTP) test result: 249 Watts

My official FTP number is 249 Watts…pretty darn good…at least higher than I was expecting 🙂

Here’s how it looks on the PowerTap download graph…the actual 42 minute test is the highlighted section after warm-up…the scale on the left that has 189 as a high number is heart rate index…corresponds to the fairly even top red line on the chart, and the 351 scale is the Power index… corresponds to the more squiggly purple line on the chart…click on the chart for a bigger view in a new window.

I had already detailed how the test is conducted in the Post before this one on Jan. 3:
http://www.irondaughterirondad.com/bike-functional-threshold-test-today/.

Here’s how it went

Prior to starting the test, I did go back and look at more of my statistics to get a better idea of how to pace the test. 

My peak power stuff for the shorter time periods was in June 2009…CP20 of 272 Watts (my average power generated over 20 minutes), after I had trained a winter in Palm Beach, flogging myself on very fast groups rides.  To estimate FTP from a 20 minute test, subtract 5-10% depending on the opinion that you’re following, so at that point 272W – (27 to 14) = 245-258 Watts FTP.  Looking at this past year, I did have a CP30 of 232 Watts on a ride on October 23, 2010 as part of a normal workout, where I wasn’t trying to maximize anything…so with light workouts for the past 2 months…some short and fast stuff in December, but then 2 weeks of partying to end the year, I didn’t really know what to expect.

Seemed to me, in looking at it, that if I started out in the 230-240 Watt range, and adjusted from there, I should be able to get through the end without blowing up, which was my primary concern.

Turns out I was probably overly conservative, since the ideal profile is exactly the same Power number all the way through, and then fall off the bike in total exhaustion 1 second after the test ends…based on that criteria, I didn’t really get all of it.

The test was 20 minutes HARD, then 2 minutes EASY, then 20 minutes HARD…I’ve broken it down into 5 minute sections:

• First 20 minutes: 237W, 235W…picked it up here since it felt too light…247W…and then picked it up again…256W
• 2 minutes easy
• Second 20 minutes: 258W, 257W, 260W, 267W…pushing _really_ hard in the last 5 minutes to maintain 90RPM which I knew was giving me over 260 Watts…max Heart Rate 156…which is where I’ve had it in the past

Overall, for the entire 42 minutes, Norm Power, including the 2 minute rest section was 249 Watts.  The good news was that I finished strong…the only bad news was that I was too conservative at the start, and therefore could have hit an even higher number.  Knowing what I know now, I’d start in that 245-250W Range, and then ramp it up about the same, so if I remained intact, and had a more perfect ride, would have probably given me closer to a 255-260W FTP.

In an interesting twist on the numbers, Joe Friel uses the CP30 number as his determination of the FTP number…in my test today, my CP30 was 249W, but this included the EASY 2 minute portion, along with the last 20 minutes HARD and 8 minutes HARD of the first 20 minute section…the Norm Power for this CP30 section was 254W, so very conservatively, probably my minimum FTP number right now, considering that there was 8 minutes of hard pedaling before this 30 minute section.

So what does this all mean

In the first place the number should be as accurate as possible because workouts are based on it…like 95% of FTP, or 85% of FTP, or 105% of FTP etc…if the FTP number is not accurate you won’t be working hard enough…or too hard.  If you don’t have a Power meter, workouts are based on Heart Rate as a percentage of your LTHR (Lactate Threshold), or RPE (Rating of Perceived Exertion), although these are not as accurate as Power, since there are a lot more variables that impact those scales…with Power, work is work.

For workouts going forward, I’m going to use a 255W base for my FTP, which I’m sure is close enough…and probably a hair conservative…until I re-test in another 8 weeks.

It’s also used to determine your best target power for racing.  If I were doing an Ironman today, with a 250W FTP, my potential right now would be roughly 70-75% of that, or 250 x (70-75%) = 175-188W Power target for the bike portion…or about 18 -19MPH.

And I have 10 months before Ironman Florida, to improve that to my target of 285 Watts FTP … and 20MPH…and since I may be even closer to 260W right now, 285W feels within reach, based on this test…although…gads…at 267 Watts average in the last 5 minutes, my lungs were turned inside out…and I’m not getting any younger…so who knows.

I had detailed my goal of 285W FTP in an earlier Post:
http://www.irondaughterirondad.com/whats-it-take-to-bike-20mph-for-112-miles/

But for today…I’m happy 🙂