I an 44 years old and have been riding just for fun for the last few years and was thinking about racing. I did my first month of threshold training on my KK PRO trainer and then I went to my LBS and did a computrainer 20 minute threshold test. My threshold power over 20 minutes on the computrainer was 280W. I weigh 59kg. Is there a magical formula that I could estimate my FTP (I assume FTP is based on 1 Hr) from a 20 minute effort. I did a similar test for 30 minutes on my KK trainer and it hurt bad! Would prefer not to ride indoors for 60 minutes to get my FTP.
BTW my KK Pro trainer has a speed to watts conversion and from what I have been finding from various sources it is very accurate. Based on my perceived effort the KK PRO was very close to the computrainer. I did not buy the computer that does the math for you as I hear that thing sucks. I put the formula in a spread sheet to get the watts. For those of you like me who can not afford a power meter the KK Pro is a good tool to estimate power. My plan is to continue to train on the KK Pro and test myself on the Computrainer every so often. The LBS charges me $15.00 to do the threshold test which I think is a great deal.
There are other ways to estimate FTP besides doing a maximum 1hr effort. Several are described here: home.trainingpeaks.comwhat is threshold power.aspxOpen ↗ . For best estimates, try to correlate the results of multiple methods independently to narrow the ballpark. If you can be comfortable within a 5-10w range for your estimate, you're doing okay.
Some (many?) folks take a shortcut and use 95% of their best 20-min power. I mention that only because it is common practice, not necessarily because it is recommended.
