Need retesting for threshold power?

cshong88 said:

Hi, I currently am training with a threshold power of 200W. I am wondering if I might need to retest my threshold power based on the results of this tempo ride which I just did. Here are the numbers:

Duration: 1:45:59.22
Work: 1093 kJ
TSS: 147.8 (.916)
Norm Power: 183
Distance: 32.57 mi

Power: min 0 max 476 avg. 172 W
HR: min 87 max 184 avg. 169 bpm
Cadence: 30 136 86 rpm
Speed: 2.3 38.5 18.5 mph
Torque: 0 279 70 lb-in

The ride was about a 7-8 on a scale of 10, 10 being hardest. I am wondering this, since my avg. power is only 8 W away from the ride becoming a threshold ride, and in fact, my norm power says it was a threshold ride...but shouldn't it be harder to do a 1:46 threshold ride?

I got the 200W as my threshold power by doing a 20 minute TT test up an undulating mountain road. BJ Basham from TrainingPeaks helped me establish the 200W, which is 95% of my norm power for the test, 211W. My average power for the test was 209W.

Thanks for your help.

P.S. Is there anything wrong with testing threshold power on a trainer? Ex: doing the 20 minute TT on the trainer then subtracting 5%? I ask because the course I did the TT on is 1 hour drive away.

-Chris

Do it on the trainer, 20 minutes as hard as you can go and use that as your FT.

Your FT should be higher. Notice the IF score of .916 over 1:45 at tempo: That would be closer to an FT ride.

Testing on a hilly TT is tough, power may be lower as a result.

I think you're correct in using 95% of your 20 min power, that's typically how I determine my FTP.

Another good test is to do a set of 2x20's and use that avg power.

I generally use my avg power and do the test on a trainer. When I test outside I use np.

Another thing to consider is if you're new to using a PM it may take a few tests to get the "feel" for how watts relate to PE. I know when I did my first 20 min test a week later I did another one after getting a better feel for the relation to watts and PE and picked up about ten watts.

Well, now I'm running into problems...

The NP from the 20 minute TT I mentioned was 211W, done on a ok...not really hilly course in that it was mostly uphill. There were slight undulations of downhills but no more than 4% grade I think. Also, I think I did a good job of not having huge power undulations in that my avg. power of the test was 209W while the NP was 211W, only 2W off.

So, with that said, I took 5% off to get 200W as my functional threshold power.

Today, I did some training on the trainer downstairs and I discovered I couldn't do much more than 185W for 2x20...

What should I take from this? First of all, when I do FT tests outside, is it OK if the terrain is more uphill or should the terrain be as flat as possible? (because going uphill generates watts a lot more easily). And as for the trainer numbers, what do I make of this? Should I have different FT for when on trainer?

Dr. Coggan, if you are out there...please help!!!