Originally Posted by smoke

you'll get spurious signals from a heart rate monitor. it isn't that big a deal if you can see it and it's not too long; you keep going at the same effort until reasonable numbers kick back in. this happens a lot when i'm riding alongside power lines. the problem with heart rate is that it varies a lot. temperature, humidity, your hydration, your efforts from earlier days, all these can cause a change in your heart rate for that day. and in the course of an hour, your heart rate will increase for the same effort. it's called cardiac drift. power is power. you either crank out 400 watts or you don't. you do your workout based on power, and if you can't, it's time to call it a day. i spent years training by heart rate and improved a bit. i bought a powertap this spring and have been training by power since, and i've PR'ed in time trials twice and finished my best in a road race. the power data has got me working harder than i ever have; it's also got me going faster than i ever have. having said all that, it's a heck of a lot of money for the thing. i simply got into a position where i could afford it back then. i think some good points were made in earlier posts; if you're not willing to put in the structured training, or don't have a goal of fast racing or time trialing, it's probably not worth the money. if you ARE willing, and DO have those goals, and DO have the money, i think power training will get the absolute most out of you that you have to give

smoke