FTP Estimation

A while ago I wrote about trying to estimate my Funtional Threshold Power (FTP). This is the maximum power you can hold for one hour and is the basis for your cycling power levels. After that initial FTP test I tried again after a few weeks and found my power had dropped. So I started resting to make sure I was fully recovered. Each time I revisited the test, things looked worse. I was questioning everything, diet, workouts, fitness and finally the powermeter.

Just before the Mt Evans HC the powermeter was really reading my power low. I felt great and didn't believe it. So I sent it back to PowerTap to get recalibrated. It was off. The sad thing is how slowly the thing drifted lower. I would be fine if it just stopped working so I at least knew it wasn't working. But to die so gradually, 5%, 15%, 20% then 50% off is hard to catch until the end. Honestly, it makes me less trusting of my wireless powertap SL hub.

Anyway, after getting the hub back from the PowerTap folks I tried Joe Friel's FTP approximation test again.

I also made some modification on my LTHR. Previously, I was using data from shorter races and not correcting for the short duration or the fact that it was a race. The new result of ~156 - 158 is consistant with the longer races I done recently too. (WP races and Mt Evans HC).

From the test on 6/3/10 my LTHR of 157 was hit during an interval with a power of 286W. So my FTP at that time would have been around 286W. This past week I hit a LTHR of 156 during an interval with a power of 293W. This means things have improved some over the summer despite all the resting I tried because of the powertap loosing its calibration.

Now that things are back on track I've been loading up the training the past few weeks to get ready for CX. We'll see how things progress throughout the fall. Currently I'm estimating, based on last years power files, that I have similar fitness to what I had last year this time. My plan was to be faster, we'll see if I can make it happen.