Boston Build Up 20k: good race, cold legs.

Photo: Ted Pernicano

On Sunday, I ran the Boston Buildup 20k. This race, as the name might imply, is part of a series of races that are ostensibly for people training for Boston, but can be run by anyone. It’s a great series — this is only my second one, but I’m a big fan. I imagine there were about 100 runners in the race, and everyone was great. Super friendly, mostly serious runners, but a good group. And it was super mellow. Registration OPENS 30 minutes before the gun. Which is a nice change from NYRR, where the registration usually closes weeks before. The miles are marked, there are two or three water stops, what more could you want?

Warmer weather. That’s what. It wasn’t that bad, say 30° at the start, but I couldn’t decide what to wear. Ultimately, I decided to wear shorts. Because that’s what I always decide. I showed up, and everyone was in tights. Including my friend Karen. Who never wears tights. Except for this time. Oh, and the two guys I car pooled with. I walked by a woman before the race and she said “just looking at you makes me cold.” I get that a lot.

I had hoped to do well. I’ve been away for about three weeks, working in Las Vegas and Chicago. I’ve been busy, but I’ve been keeping up with my running pretty well. I had a run in 7° weather in Chicago, which was a great 30 minutes. Followed by 45 minutes of agony. But I did get the sense that Chicago would be a great running town. Except for right now.

The race was a 20k, which is, indeed, shorter than a half marathon. By about .6 miles. I looked up the distance in a predicted time chart — a great resource provided by Greg McMillian’s site, and it had me down for a 7:04 pace and a time of 1:27:37. So I decided to try to hit that number.

The first mile was good. Felt great. A little cold maybe. Especially my legs. Which were in shorts. 6:57.

Mile two and three, right on track at 6:59.

Mile 4, big hill. No really. 7:24. Mile 5, no hill. Felt guilty about mile 4. 6:58. Mile 6, 7:19. A little stressed now. Mile 7, 6:58. Mile 8, 6:40. Don’t know quite how that happend, but I’ll take it. Mile 8, 7:05. Mile 9, 6:42.

Mile 10. I could right a novel about Mile 10. Huge freakin hill. Pain. Misery. 7:32.

Mile 11, 6:39. End was in sight!

Overall time was 1:27:47, average pace of 7:02. Total distance from Mr Garmin of 12.5 miles. For whatever that’s worth.

So I was thrilled with my time — right were I wanted to be. Now am worried I should have pushed harder. That being said, Monday, the day after the race, I decided to celebrate my race with a nice recovery run. Made it to the driveway past my own before I realized I was in too much pain. So I came home and ate. That was my recovery jog.

Overall, the race was unique — it felt both supportive and competitive, but at the same time it felt like everyone was running their own race. I was passed a lot in the middle of the race, which surprised me. Most times I find shifting in position come very early on or very close to the end, or if someone gets injured or is having a bad day. I wonder if different runners were attacking the race different, some folks trying to do negative splits (in a 20k?) or were doing a progression run or whatever. But it was a great feel, nonetheless. When I crossed the finish line, there were handshakes all around. One guy, who tried to pass me in the last 20 yards, was all smiles. As was I. He asked my time, I guess he wanted to add a few seconds to it to write down his own.

We took a nice picture afterwards. I put on long pants as soon as the run was over. I was much warmer.

Written by Greg Cohen



Congratulations on your run. Well done indeed on running to (almost exactly) your target time.

Do you get course profiles before the races? I guess you could use MapMyRun to generate them if not and then you could take those into account with your schedule. 7:32 up that novel in waiting at mile10 could have been absorbed in the plan and saved you some worry perhaps. Maybe some of the folks passing you in the middle of the race were pushing in advance of the mile 10 hill?

Do you ever use embrocation to warm your legs? I used it quite often when cycling. The smell was awful but it helped to stay warm and the process of massaging it into your legs is a good way to check for tight spots. Just remember to wash your hands after application (and before wiping your eyes or going to the bathroom).


Ruben, there are profiles for the major races, but not for smaller ones. Well, that’s not true — if someone posts a course on mapmyrun or a similar site from their GPS, the elevation profile is then posted as well (like here:, that’s for Boston, but I imagine it’s off someone’s watch). I never know quite what to do with that info though — I think it’s better to take the suffering as it comes!

I haven’t tried embrocation, it sounds awesome. As in inspiring fear, that kind of awe! But it sounds powerful indeed.

Marci, You, Ruben (my other commenter on this thread) and I smoked more than most! The only thing I miss is the cigarettes!


I may be overcomplicating things but with the course profiles I would think about adjusting the pace to take the profile into account.

For instance on the Boston course you’ve got a bit of an incline to tackle from 26.5k to 34k. It’s not much of a climb but it’s long and at a tough point in the race. So if you were planning on a 7:30 pace overall you might expect to run 10% slower (or 8:15) for that section.

You would hope to make up that time on downhill sections. That may well be different running than cycling though. For me the point in getting into detail on pace predictions is to avoid disappointment in the hard parts and to avoid over-stressing your body trying to make unrealistic intermediate targets.

Perhaps having projections for 5k sections of the race would make this easier. I may be becoming bossy and boring but I am interested in this stuff probably because it combines maths, sport and suffering into a particular kind of geekery. I am as ever in awe of your endeavour.


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