billh

haven't bought a power meter yet but started reading Allen and Coggan's power meter book as well as Friel's Training with an HR Monitor. Both books are very positive on power meter training but I'm a little confused. I think Friel wrote about heart rate as the "input" to the system and power as the "output" and both wrote of the problems training only with HR because "low" HR can indicate fitness or not enough effort, and "high" HR can indicate a lack of fitness or appropriate hard effort. However, it makes more sense to me to train the input to a system rather than the output. That is, if really believe in periodization, ie. that I want to do a particular workout in a given zone, if I train according to the output, eg. power, I could be way out of the proper heart rate zone, eg. if I feel crummy or am tired during a given workout, then my heart rate could be too high if I try to maintain a given level of power for an aerobic zone workout. Seems like HR takes into account all those confounding factors, appropriately. What am I missing?

NomadVW 

Heart rate is the physiological response to the effort of power. Your heart rate can be affected by a number of factors like adrenaline, temperature, caffeine, hydration, (the lists goes on). Yet, while each of these are being affected, the only one that is truly "objective" is the power your legs are putting out.

I see that you posted to the wattage google list as well. You're going to get the most information there, for sure.

ratebeer

Very cool, bill. Thanks for the book refs. I hope to be into this kind of training by Summer.

You can always test your output on any trainer where resistance is purely, or very nearly a function of just speed.

Then your speed and how long you hold it becomes an accurate relative measure of power output. If you want watts (for whatever reason) just throw your numbers into a bike physics calculator. The result will not be an accurate number of course but when comparing your own workouts will surely deliver precise deltas showing true *relative* changes in your performance.

It's very cheap, very easy and can be even more effective than power meters -- especially ones with documented lack of reliability and measurement accuracy.