Originally Posted by Jughed

Same here - I just set my 30 min PB a few weeks ago. Out of the blue, no preparation, I decided on the way to the bike path to do a 10 mile TT. Started below threshold, or what I believed to be threshold, and ramped up from there. At mile 6 I was well above what I thought my threshold power was, at mile 10 I was above that, at mile 15 I was even higher, and I had more left in the tank. At mile 15 I was pushing 20% more than my last 20 min test average.

I typically fail miserably at planned FTP tests.

That being said, I did push close to 1700W on a sprint one day - I was blown away by the number and thought I had superhuman strength. The power meter batteries were dying, I knew this, but they blipped out a reading that I in no way was capable of.