Why the marathon is not for me

"Are you training for a marathon?"

I get asked that question a lot by people who find out that I like to run. It's a totally understandable question, given the prominence that the marathon has assumed as the presumptive "event" for recreational runners. And yet, I have pretty much zero interest in running one. To be sure, I say that with absolutely no intention of downplaying the accomplishment of those who train for and run (or try to run) one. If that's what gets someone motivated to run, that's great. It's just not for me.

I was thinking this particularly at a recent 10K race. After finishing, I was chatting with the 5K winner and another local area runner who happened to stumble across the race while on a training run, and both of them were trying to convince me to run a marathon. When I expressed a lack of interest, the local area runner (whom I know from seeing him at other races) explained that it's the only way to experience the challenge of getting past the "wall."

The marathon certainly presents a challenge, but one of the wonderful aspects of running is that you can make any distance a challenge for yourself and your current level of fitness. The wall poses a problem that you don't face in shorter distance races (not even the half marathon), and so obviously a marathon requires some additional skill that, say, the 10K does not - specifically, the ability to consume and metabolize calories mid-run. But it's equally true that the 10K - or better yet, the 5K - requires the ability to tolerate a significantly less comfortable pace for the duration of a race, compared to a marathon.

What is the goal?

I suspect what makes the marathon seem like THE accomplishment for non-runners or even beginning runners is the staggering distance. 26.2 miles is an awful lot of mileage. The most I've run in a single session is just under 14 miles, so I certainly acknowledge the immensity of the distance.

But running a race isn't just about covering the distance. I mean, that is part of the goal, and for a first-time race at a given distance, it might be the only goal. But the goal might be to finish the race under a specific time.

For example, four hours is a common target for runners who are neither elite nor sub-elite. One commentator who looked at a number of big marathons estimated that just slightly over a quarter of runners finish under 4 hours. (In case you're wondering and don't want to click through, it's around 1 percent who finish under 3 hours.)

The average finishing time for a marathon in 2013 was 4:16 for men and 4:41 for women, so depending on the male-female ratio of racers, would be somewhere around 4:25 overall, give or take a few minutes.

Put another way, finishing a marathon is definitely a big accomplishment, but is a 4:25 marathon finish harder than, say, a sub-20 minute 5K?

Judging from my own racing experience and race calculators, I don't think a 4:25 marathon is anywhere close to the challenge of a sub-20 minute 5K.

My racing results

Since I started running in 2011, I've run a bunch of 5K races, about a dozen 10Ks, and two half marathons. Since race calculators get progressively less accurate when they use race results from very dissimilar distances, my half marathon results would obviously give the best predictions of what I could run a marathon in. If you use my slower half marathon time (1:40:30), you get a predicted marathon finish time of 3:29:34 (Runner's World), 3:30:31 (McMillan), or 3:28:46 (Daniels Running Formula) - basically, all clustering around 3:30 or so.

To be sure, I'm always slower than what the calculators predict for longer distances, and faster than what they predict for shorter distances, which may suggest that I have more fast twitch than slow twitch muscle fibers. I don't think I can run a 3:30 marathon. Probably more like 3:40. Even so, that would put me comfortably faster than a four hour marathon, and well ahead of a 4:25 finish.

What about 5Ks? My PR there is 20:25. That may seem kind of close to sub-20, but 25 seconds is a pretty long time in a 5K.

Given that I run shorter distances faster than race calculators would predict, I think it's extremely doubtful that a 4;25 or even 4:00 marathoner could run a sub-20 minute 5K. Indeed, the Runner's World calculator predicts a 25:01 5K finish for the latter.

Of course, there are lots and lots of marathoners who are much faster than 3:30, or even 3:00, and for those runners, a sub-20 minute 5K would be fairly trivial. But that still doesn't make the 5K "easier" than the marathon, even for them. It just means that given their state of fitness, sub-20 minutes is too easy of a benchmark for the 5K. For a 3:00 marathoner, the Runner's World calculator predicts an 18:46 finish for the 5K. I bet such a runner would find a sub-18 minute 5K to be quite a challenge.

This is what I mean when I say that you can make any distance a challenge for your given level of fitness.

So why not the marathon for me?

This doesn't necessarily answer the question of why I've picked the 5K and 10K as the distances to test myself, rather than the marathon. So here are my specific reasons, which aren't meant to dissuade anyone else from choosing the marathon:

1. Given my suspicion that I have more fast twitch than slow twitch muscle fibers, I'm just playing to my strengths.

2. I'm running about 35-40 miles a week right now. Some studies find injury risk correlated to increased weekly mileage, with 40 miles being one of the thresholds. I probably have enough of a base to finish a marathon right now, but with my long runs topping out at 10-11 miles, it's not configured right. So I'd either have some weeks where half my weekly mileage is tied up in a single long run (meaning fewer runs the rest of the week, or shorter ones than I'm used to), or I'd have to up my weekly mileage.

3. Pro runner Lauren Fleshman said it best in her column on why the 5K is "freaking awesome":

It encourages you to develop a combination of endurance, speed, and strength. You can train for it and still have a life. You can race one every weekend and still be able to walk normally. If people ran more 5-Ks, I'm positive the average life satisfaction of humans would increase dramatically.

After my first half marathon, I felt achy and sore in a way that I never do after 5Ks or 10Ks. The second half marathon went better, but I can imagine that the toll the marathon takes isn't a straight linear increase over the half, but something much worse.

4. I find the pacing of the half marathon to be weird. For me, a 7:30-7:40 pace isn't an easy stroll, but it doesn't seem fast either. There's a temptation to go faster, but that would lead to disaster. I'll admit that I can see how this adds a strategic dimension to the race. Put simply, it's strange to be able to talk while running in a race. For me, I like the feeling of running at an uncomfortable pace, and for the 5K, being on the edge of red-lining.*

* I'm not as big of a fan of the mile, even though I run the mile faster than my 5K time would predict (naturally), but I have to say, there's no feeling like what I felt the first time I ran a sub-6:00 mile in my forties, especially during lap 3 when I was thinking to myself, "Whoa, I'm going to do this!!!" There wasn't much thinking during lap 4, other than "ugh ugh ugh ugh...."