Plenty of runners use a GPS watch, and plenty of those offer heart-rate monitoring. As a mid-pack runner, I didn’t give it much attention for years, but lately I’ve found that, even when not using it as a primary guide for training and progress, this data offers a window into what’s going on inside our bodies as we run.

The most practical info I’ve gotten so far is about warming up. Over time I’ve noticed that if I just lace up and start running, even at a very easy pace, my heart ramps up quickly to a rate that usually comes with a full-on sprint. If I keep running, it takes quite a while to settle down to a normal cruising rate, which is fatiguing and seems like it must waste energy. If, on the other hand, I stop running for even a little while, the rate drops down quickly and when I start up again it settles right into normal cruising range. I can’t speak to the exact cause here, but what it feels like is that, to run efficiently, my body needs to adjust its internal settings and biochemical processes from what they are in lighter activity. When I jump right in, the machine is trying to put out high power while still set to ‘idle,’ and that over-work makes it take longer to reset itself. Signaling the body that an effort is coming by just a little bit of running, and then allowing it a brief pause, provides time for biology to catch up with intent

With that info, I’ve been trying a new warm-up on days when I’m aiming for my best performance. Instead of just starting slow and increasing speed as I feel more loose, I alternate a minute or two of running with a similar period of walking around, then run some more, then walk, and so on. Over ten or fifteen minutes, I work those short spurts up from very gentle to almost a sprint. None of that is enough to drain reserves or feel fatigue, but when I start the day’s real work all the internal dials and knobs are on their ‘RUN’ settings and I can put out whatever level of effort is desired at a reasonable heart rate, not the frantic over-revving I’d get from a cold-start. I used that strategy before a recent 5-K and had a really satisfying run, so I’m gonna keep at it.

Another thing I’ve noticed: as a long run goes on, my heart rate slowly goes up, even though I’m holding the same pace (or, more likely, slowing down!). In other words, the longer I run, the higher the heart rate for any given pace. Again, I’m no physiologist, so I can’t say exactly why that is, and I haven’t figured out how to make use of it, but it’s definitely interesting.

Each body is unique and so is each person’s heart rate profile. There are tables out there that say what the resting and exercising rate is likely to be for a certain age (rates generally decrease with age) but they may not apply to you. I happen to be a smallish person and my heart rates run considerably higher than the tables indicate for my age – I call it hummingbird syndrome. To get the most out of any heart rate monitoring, follow it long enough and frequently enough to have a good idea of your own individual resting range, steady-state-running range and high-exertion or maximum range.

(Besides, checking heart rate now and then is a useful way to get your mind off of how hard you’re is working and sweating!).

And the beat goes on…