My wife loves to run. I, in contrast, find running to be boring and unpleasant. But I run all the same, because it keeps me relatively thin and makes me feel better for the 23.5 hours per days that I’m not running. Before I had a normal-ish job and a family, I was running a fair number of miles – around 35-40 miles/week. But life got in the way, and I’ve been off-and-on for a few years now. The problem with off-and-on running is that it keeps you just fit enough to get through the runs, but not fit enough to get through them in a pleasant manner. I’d find myself running five miles one week, twenty miles the next, and feeling exhausted with every step. Combined with my natural distaste for running, this unpleasantness made for an exercise regimen that was hard to stick to.

So, last summer I decided that I’d mix things up, and I bought myself a heart rate monitor. (This one.) I figured that I wasn’t enjoying my running routine, and it wasn’t much of a routine anyway, so I might as well go whole hog into a training plan that was totally foreign to me; I didn’t have much to lose. I’ve been faithfully training with the heart rate monitor for about a year now, and overall it’s been a really positive change.

The first thing I did when I got the watch was to ask my wife if she had any resources for training with a HRM. Surprise! she had several, and she grabbed one for me from her unreasonably large library of running books. I found Heart Monitory Training for the Compleat Idiot by John Parker to be a helpful resource: written specifically for runners (as opposed to, say, triathletes), a very quick read, and full of advice that I found sensible and not overbearing.

The main takeaway from the book (spoiler alert) is that most people run most of their miles far too fast. When your “easy” runs aren’t legitimately easy, you’re never rested for the hard runs, and you never build the kind of stamina that you really need for distance running. (At the risk of sounding like a running nerd, the idea is to do the majority of your miles under your lactate threshold.) The heart monitor is used as a gauge for enforcing easy runs. The magic number is 70%: on easy days, keep your heart rate below 70% of your heart rate reserve, a figure which is calculated by subtracting your resting rate from your max rate, and then using your resting rate as a floor. For me, the calculation was something like this. I did a max heart rate workout (found a steep hill on a hot day and did repeats) and got my HR up to 192. Measured my resting rate over a couple mornings and called it 58. 192-58 * 70% = 94, which when added to 58 gives me an easy run ceiling of 152 BPM.

The first thing you learn when you start staying under this target rate during easy runs is that holy crap this is slow. I was accustomed to doing easy runs around 8-8:30/mile pace. With the HRM, on a hot July day, I found myself running at 10:00+. You also learn that hills are really serious business when it comes to heart rate. To stay under the 70% threshold on hills of any size, my shuffle devolved into a near-walk. It was torture. Physically, I had no idea what to do with my body when going that slow (your form totally changes). And mentally, I was humiliated getting passed by grandmas, kids, invalids.

But, I stuck with it, and after a few months things started to click. The weather started to cool. I found techniques for modifying my form up and down hills that would let me maintain some speed while keeping my heart rate down. And most importantly, I think that I really was building the kind of aerobic fitness that’d been promised in the book. Within four or five months, most of my easy runs were back down at 8:30 pace or faster – and they were all below the 70% HR threshold.

Some cool things happen when most of your runs are easy. For one, you can really go balls out on hard runs. Because there’s no latent fatigue from the previous few days (and because I know I’ll get legitimate rest over the ensuing days) I can pretty much run myself into the ground during workouts. Another benefit is that you can immediately start adding distance, because you never, ever feel tired during easy runs. I end every run thinking, gee, I feel like I haven’t even gone out yet. For someone who was used to feeling like shit after every run, this is a huge and welcome change that makes the whole endeavor much less unpleasant. Tracking your heart rate also gives you window into your general health. You might feel fine and plan to hit the streets at your normal pace, but if you are coming off of a cold (or have one coming on), your heart rate will be elevated, and you’ll be forced to slow down.

A couple weeks ago I ran the first road race that I’d done in a number of years. Looking back through my running logs, I see that the last time I ran a 5K at that pace, I’d been running twice as many miles per week, and I was five years younger. Granted, I’m still not running very fast in any objective sense, but this is still a pretty cool side effect of running a bunch of junk miles.

If you’re a runner and feeling like you’re in a rut – or if you’re someone who’s tried to run in the past, but could never get over that initial god-how-can-anyone-endure-this-torture phase – I highly recommend getting a heart rate monitor, and learning how to use it during training. It makes running more interesting and less painful. (Though I still don’t like it like my wife does.)