Zone Training

So, I was trying to think of something to post for today and was flipping through back logs of "Ask the Coaches" when I came across this question: when targeting a heart rate workout, what percentage of that interval needs to be in that zone? Hmmm... never thought about that... I just kind of read the words and ran whatever and kind of hoped that I was doing it right. Basically, the guy asking the question had noticed that his heart rate does not reach the correct bpm until well into the interval (especially for the shorter intervals targeted by the higher zones / effort levels). Makes sense... so, do you need to "warm up" for each interval or what? Turns out, the whole point interval training is to simulate a race, but multiple times over the course of a workout (practice makes perfect afterall). So, being that your heart rate starts off lower at the beginning of a race and then gradually climbs, this is the same pattern that your interval should follow. Oh good, because I certainly wasn't looking forward to "warming up" before each mile repeat! #20