I have been monitoring my heart rate in every workout and I think I am getting a feel for it. Based on a resting heart rate of 61 and a max heart rate of 192, my heart rate reserve would indicate the following zones based on the calculator at MarathonGuide.com which can be found here. If course my max heart rate could be above 192. The highest I can seem to push it at the end of workouts is 188. When I do my first measured mile calculation in a few weeks on a track I imagine I might have a better number.
My experience seems to match the above chart. When I push my heart rate above 170 I can definitely feel something shift and know I am on borrowed time. I have looked over the heart rate data from a bunch of different kinds of workouts I have done and it seems that I spent most of my time in zone 3, followed by zone 2 and then 4. Not surprisingly, the workouts where I am working on speed I find myself in zone 4 a lot more.
What I am still a bit stymied about is the relationship of pace to heart rate. I would swear it is not linear, but I really don’t have a great way to figure that out. It seems to be something like this:
- 12:00 mm: HR around 154
- 11:00 mm: HR around 160
- 10:00 mm: HR around 168
- 9:30 mm: HR around 172
- 8:30 mm: HR around 180
Clearly the 8:30 pace is out of my reach. I can sustain that for approx 3 minutes. But a 9:45 pace actually feels comfortable when I am taking walk breaks every 3 minutes for 30 seconds. But I assume that this would still result in lactic acid buildup in the marathon and ultimately disaster. I really have also been noticing that things like temperature, hydration, sleep and other factors can change up the heart rates. At this point my best guess at this point is to just run whatever pace that day is around 160-165 (for marathon pace).