Hey, if you have time, I'd love to hear how you use the heart rate monitor, especially to measure capacity. I know about some of the VO2Max tests, such as the YMCA test, etc. but I don't think that is what you are talking about. I would guess you are making sure pulse stays constant as you slowly increase distance or speed?
And if you have a link that describes the strategy you use, I'd love to read about it. I got hafl of a Garmin monitor, but I need to get the other half. I want to pull my pulse down some - it's always been on the high normal side - and I'm wondering if I can do it with low medium intensity jogging. My pulse was humming along at 120 about 20 minutes into my jog (72% of 165/220) and 125 at 35 minutes (76% of 165/220).
Sure! I first got into it with this book http://www.amazon.com/Heart-Monitor-Training-Compleat-Idiot/dp/1891369849
but am slowly moving to Phil Maffetone's methods which I feel are a bit more mature. It is basically as you suggest; identifying a safe and comfortable heart rate zone to do the majority of your training. Before paying attention to HR I was running too fast to be useful as a slow, low risk run, and not fast enough to really advance aerobically. It was a general 'no-mans land' where it feels like decent exercise, but the risk of injury goes up and isn't optimal for progression. So you switch to a strategy where most of your running miles are at a very comfortable (even slow) pace, and you are then free to introduce a small number of targeted intense sessions that really have purpose - quality runs. For me this is one day a week for interval sessions, and one long run a week (>15miles) with a strong finish.
To begin with, most people find their calculated heart zone to be comically low, and would even have to walk to ensure they don't exceed it (or more likely run for a few mins and have to walk for a bit before repeating). It lasts a few weeks and lots of people give up because they like to run faster. But with enough time your body adapts and you can freely bank the mileage with a much lower chance of injury. The heart is a great indicator of general health, and when you build up historical knowledge of your pace and heart rate in combination you can readily identify when you might be overtraining, or even when you might have an infection or cold about to come up on you (i.e. way before you can experience direct physical symptoms).
As an example my standard HR zone is < 137bpm for my general low intensity runs. Even though I run with this artificial limit imposed on me it's still fun to track the improvement in pace as the weeks roll by. When I started I would typically be running at over 6:30/km pace, for a 10k well over one hour. These days I can hustle along at 5:00/km pace for a 50min 10k, with the same level of effort.
Awesome job on the 7 5k's on the trot; that's something I've never done!