and in laymen's terms.
I have watching the Tour De France and have read throughout this forum, but I am still not clear on the importance of heart rates and their effects on endurance and training. For example, the commentators in the Tour have frequently said that if such and such a person sustains the red zone heart rate for a really long time, it will really hurt them tomorrow. Is that in part because the heart is a muscle?
At any rate, I was hoping someone could boil down to me in simple terms the importance of the different zones of heart rate, and also advise me on what my max heart rate should be (36 yrs old, female).