Is there any way besides the perceived exertion scale to calculate where you should be with your intense intervals? It seems so subjective (I hate the pain scale from 0 to 10, also). Can you estimate when you're at the highest level from your heart rate, or is the delay in getting to that heart rate an issue?
"If you drop an egg, you don't say, 'Oh, shoot' and drop the other 11, do you?"
-Source unknown, but obviously brilliant
Reached goal 4/16/2010...but kind of afraid to look these days