Sunday, November 4, 2012

US Half Marathon

The US Half Marathon was my second "training race" for the Sacramento International Marathon four weeks from today, where my goal is to qualify for Boston. My idea was to do a 10 km race in October, a half-marathon (21.1 km) in November, then the full marathon in December (42.2 km). This is a nice factor-of-two progression in race distances.

At first my goal was to use these races to practice my marathon pace, but this plan didn't last long. As each race approached, I was drawn to the attraction of distance-cspecific time goals: 40 minutes for the 10 km, then 90 minutes for the half-marathon. Unfortunately my 10 km race yielded a disappointing 41:46, well off my target.

Going into the half I was forced to admit my 1:30 goal was probably unrealistic. While I like to believe that my running fitness is better than it was last August when I ran 1:30:56 in the San Francisco Giants Half Marathon (as "Fred"). But that course, while sharing many of the elements of this one, was clearly easier in the differentiating elements. The Giants race includes a long out-and-back on the Embarcadero, while the US Half winds through Presidio hills, and does a loop over the Golden Gate Bridge pedestrian walk, down and under the bridge along a dirt trail, then up the steep Conzelman Road to the west path (normally for cyclists) which we take back to the City. The Giants race gained 38 meters while the US Half gained 211, according to Strava. The difference of 173 meters takes its toll, especially on me since I run relatively slowly down hill and am less able than others to recover time lost going up.

Despite the 7 am start time, since it was the first day of standard time I had no problem getting up in time for a 4 am breakfast, then at 5:20 getting on my bike for the spin across town to the start. I got there right after 6 am, so had plenty of time to use the porta-potties, lock my bike, drop off my backpack, and relax.

At 6:50 am, ten minutes before the scheduled start, I slotted in a bit back from the front of the line. I didn't want to be swarmed in the initial rush by starting further up. This was the first big road race I've done where there were no signs offering pace guidance for staging. In retrospect I was too self-critical in my start position selection. I spent most of my time waiting squatting in the start area, trying to relax.

At the start, first nothing happened, then the slow shuffle to the line began. The line was approaching both too slowly and too quickly. At this point I'd have preferred for people to let a bit of a gap open in front of them so we could hit the line with some speed, but instead I was still in slow walk mode when I hit the timing pad. Game on. I immediately began threading myself through gaps in the crowd to try and move up to people at close to my target pace, which was around 4:15/km.

2:13 into the run and I'd gone only 430 meters. That included 22 meters of elevation gain, but a similar climb at the end of the race took me only 1:47, so I'll estimate I lost around 25 seconds in this early scrum. Normally slowing results in some offsetting recovery but since this was at the start of the race there was nothing from which to recover yet.

Finally I slotted into some groups which appeared to be going a good pace, nice and relaxed but not effortless. Races are funny like that; looking back not he data I was going too quick here. I heard one woman next to me say she wanted to drop back to a 7-min mile pace. That was my target as well, but I'd need to be a bit faster on the flat & fast sections to average that with all of the climbing in the route.

At mile marker 1 I tried to see my time on my Garmin but it was hopeless: my sunglasses had fogged up in the unusually humid morning air. I was relieved: I decided to run by feel rather than addicted to what my Garmin told me. Indeed, after the race I heard from some other runners the mileage markers were imprecisely placed, and thus the pacing information would have been misleading anyway.

Rest stops were approximately every two miles. I decided to get something at every one to practice my technique. "Water or Cytomax?" volunteers shouted as I approached stop #1. I decided to lead off with water, switching to Cytomax later. As I reached the water table I moved over and felt a small bump from behind as someone brushed my shoulder. "Asshole!" he shouted. I tried to ignore him. Relative to my experience in bike races what had happened was nothing, a small bump, zero danger. At following stops things weren't as crowded and I never had another such incident, except for a runner who accidentally stepped on my heel from behind. That was clearly his fault, but it didn't bother me in the slightest. Stuff happens in races.

I grabbed the half-filled water cup fine and even managed to take a sip without it going up my nose. I decided to keep running rather than slow, taking sips as I could. Finally I was done. But by now I was well past the drop zone so I decided to hold onto the empty cup until the next water station, careful to keep the opening in the trailing direction to minimize wind drag.

On an 11.7 km training run a few weeks ago in moderate temperatures I lost 800 grams in water. That extrapolates to 1600 grams lost in a half-marathon. To replace all of that I'd need to drink 1.6 liters of water. Obviously that wasn't going to happen. But I don't need to replenish all of it: in a marathon, it's typical to lose around 3% of body mass. For me that's around 1.7 kg for a full marathon, or 850 grams for a half marathon. So I needed to replace at least 650 grams, or milliliters, to avoid losing weight at faster than a 3%/marathon pace, assuming the rate of loss was the same as on my test run. With the half-filled cups at the rest stops that would certainly require drinking at each of the stops here.

At the second stop I dropped my empty cup then took another cup of water. This time, for some reason, drinking didn't go as well, and water ran up my nose. I decided to invest a few seconds in a fast walk for drinking. I took maybe four walking steps before I finished the water, then I was on my way again. Since this walk provides some recovery, I get some of the lost time back in a faster sustainable pace once I start running again.

By this point we were approaching the marketing highlight of this run: the Golden Gate Bridge crossing. When I'd registered, I'd expected the auto lanes would be closed, allowing us the rare pleasure of running across the bridge without the interference of cars. But I had no such luck: instead of stopping car traffic, they gave pedestrians and cyclists the boot. I did see a truck hauling a trailer with bikes mounted on it, so perhaps they were running a bike shuttle. But this was a disappointment. As I began running along the eastward, pedestrian side path, I was accompanied by the deafening sound of freeway traffic on my left. Fortunately there wasn't a strong exhaust smell, but I had to wonder what the air quality was. Runners can run along the side path any time they want, but honestly I've never really wanted to. There's so much nicer places to run then along freeways.

As I ran, I felt my foot slip slightly on a metal plate on the running path. I tried to keep my path as straight as possible while avoiding these plates, which were placed irregularly. When I'm running, I always try to optimize: hit the tangents in corners, optimized draft behind other runners, stay on the most efficient surface. Global optimization requires a compromise between these factors, and trying to hit the net optimum is part of the fun of racing.

I reached the other side and followed runners ahead of me off the path and through the parking lot at the Vista Point Lot. We were quickly through the lot, and then entered a dirt trail I hadn't known existed. It wend down, then under the bridge, connecting with Conzelman Road half-way up its ascent from the outskirts of Fort Baker up to the west side of the bridge. The descent was a wonderful break from the bridge path: much less noise, a gorgeous view of the mist hovering over the water in the Bay, and the soft dirt path a pure joy to run down. It reminded me why I like trail running so much.

I did my usual measured tempo not he climb of Conzelman. I'm a slow descender, as I've noted, but while I'm a lot better at climbing, I'm not as fast as I'd think I'd be based on cycling. For example, of the 68 runners who've so far posted their races on Strava, I'm tenth on this climb, 2:58 versus the top time of 2:19. From his Strava time that runner, Benjamin Leibald, ran 1:19:25 for the full course. I wish I could run that fast.

Approaching the bridge again we reached the third water stop. Having taken water at the first two, I chose Cytomax here. Once again I walked a few steps to drink it efficiently and it tasted good. I'd brought some PowerBar-branded gel chews, tucked under my compression sleeves, but I felt no desire to eat these. Getting a bit of sugar with the Cytomax was a good idea at this point. I ended up getting Cytomax, at the fourth stop as well later in the run.

Running back on the western side had added novelty because it's normally restricted to cyclists. It was hotter here: I could feel the heat from the cars on the road. And I suspected there was a tailwind in this direction, as I felt fast. I was now heading toward the finish line, so felt a dose of motivation to pick up the pace. But it was still fairly early, not much past half-way, so I didn't want to get too enthused, but didn't want to get slackidasical either.

I was running next to a larger shirtless guy when we were passed by a guy not much bigger than me who appeared to be gliding over the road more then running. He didn't even seem to be trying, just coasting along without effort. I decided to try to follow him, to emulate what he was doing, but I'm sure I wasn't successful. We reached the end of the bridge and turned onto the path which descends from bridge level and once on that descent he was gone. I never saw him again.

Having come off the bridge, we ran down to Marine Drive toward Fort Point, a landmark in many of my longer runs. As we descended this road we passed a quite large woman, number pinned to her shirt, struggling up the hill. I was impressed: this was going to be a long effort for her. How many women with her body would attempt a half-marathon? I cheered her on.

It was slightly confusing what side of the path we were supposed to follow here, but once we were on Marine Drive it was clearly on the left. On the right side of the roughly paved road decent-sized groups of runners were returning. This was a nice reminder of how many people were faster than I was. But I wasn't as far back from them as I feared: the turn-around was well before Fort Point. Past the pylon marking the turn-around, it was straight to the finish line without any further convolutions.

After returning on the rough pavement, we entered the dirt trail along the water. This is a very popular trail for runners and dog walkers, and I saw no signs indicating a running race was occurring. Of course it's conventional to run on the right on pedestrian paths, but without course markings I ran on the left, since the path was curving that way. Courses are always marked assuming runners follow "tangents", the shortest legal route, and I didn't want to run even an extra meter than I had to. But this trajectory involved a degree of conflict with the 3-abreast and dog-walking crowd. To be honest, it annoys me when people see a race obviously in progress and decide they're still going to take up a wide chunk of the path. The term "pig-headed" entered my head on way more than one occasion. Maybe I'm the one who's pig-headed for thinking my oh-so-important race really matters, that if I were to lose a few seconds staying out of the way of people enjoying the morning it makes any difference. But when other people are racing I certainly show respect for that and stay out of their way.

After the path, we diagonalled to the paved walkway on the side of Marina Blvd. This went on for further than I wanted, Fort Mason hill looming in the distance. I was surprised to pass the fifth water stop here. It was too close to the finish to get much benefit from drinking, I felt, but I took a water and dumped it on my back for cooling. I felt a bit guilty about wasting a cup and filtered water this way but sometimes a bit of water on the back or head can provide a jolt of energy on even temperate days like today.

Finally, Fort Mason. This was it: up, down the other side, then a sprint for the finish. I put in a hard dig on the climb and a volunteer shouted "That's the way to attack the climb!". It was corny but it all helps. On the Strava segment I defined for this climb I was 6 seconds faster than I'd been at the half marathon last year, ranking 6th/54 who triggered the segment today. However, following the climb is the descent. I decided to try and lengthen my stride, relax, and let gravity carry me down rather than making a strong effort. This proved to be a failure, as I was 5 seconds slower than I'd been last year here. Of course it's possible these time differences are in part due to GPS noise, but I'd prefer to believe I can learn something about how I executed this part of the course today. The conclusion: "gliding" down hills isn't fast, you need to work hard as well. But I already knew this from trail running where the guys going fast down gradual hills always seem to be breathing harder than me.

This was it: the sprint for the finish. It wasn't much of a sprint. But I consoled myself with the message that if I had been able to sprint, I'd have been better off going harder the rest of the way. The fact I tried to release all inhibitions, recklessly throw the throttle forward, and didn't have much to give was a good sign.

Cara was there! "Go, Dan!" she shouted. It always makes me happy when she comes out to watch.



approaching finish
approaching finish (Cara Coburn photo)

The clock was there, ticking, as always way faster than it should. I hit the finish at close to 1:33, which translated to 1:32:26 in chip time. I was 82nd place overall out of 3632 total runners (80/1781 males, 1851 females). That's top 5% of males, so I can't complain. But of course I always want to be faster.

So could I have broken 1:30 on the Giants marathon course? There was that estimated 25 seconds lost from my poor start position: with a better start position maybe I could have gotten 1:32:01 Then there's 173 meters of added climbing If that adds 2:01 that works out to 5147 vertical meters per hour gained in time. I certainly think for two courses of the same distance, one gaining and losing 514.7 vertical meters (more than Kings Mountain Road) and the other dead flat, the one with the vertical gain would be at least 6 minutes slower. So I think I could have cracked 1:30 with my fitness today had I been running the flatter Giants route. But of course it would be better to have actually done it on this course, then no calculations would be required.

Another interesting aspect is the dirt. I definitely seem to run slower on the dirt. When I look at my data, my kilometer splits on the road tend to be in the 4:05 to 4:10 range, but on the dirt they invariable go up into the 4:20's. Running on the dirt is more enjoyable and less impact, but it shouldn't be a shock that it would be slower. Every time you push off with your foot on the dirt it slips a bit. We ran that dirt trail in both of these marathon courses, dodging pedestrians. I don't think there's anything like that in the Sacramento course.

2 comments:

Christine said...

Go Dan! Excellent finish. Wowee. And you had your woman out there cheering for you! You should be feeling special about now.

Unknown said...

Great race report. Those metal plates on the bridge can be slippery when wet, I found out the hard way a couple years ago.