Occassional thoughts about orienteering

Saturday, January 31, 2009

Today's race - fun with QuickRoute


I ran a local event at Longview this afternoon, put my GPS track onto the map using QuickRoute, and spent a few minutes looking at the results.

First, I look at the heart rate histogram.

The graph shows that my h.r. was higher than usual (my normal avg. h.r. for a race is around 168). When my h.r. gets over about 168, I usually have to ease off and recover a bit. My h.r. today averaged 172.

Something different was going on today. I think it was two things. First, it was unusually warm (mid 60s...i.e. nearly 20 C). Second, I bruised my ribs earlier this week and had trouble getting a deep breath. I found myself taking lots of shallow breaths (like a dog on a hot day). I don't know enough about physiology to be sure, but I'm guessing this resulted in an unusually high h.r. that I was able to maintain. Unfortunately, that unusually high h.r. didn't mean I was running unusually fast!

The next thing I look at is the pace histogram.

What should I make of the pace graph? I'm not sure. To my mind, this graph looks good - the peak is toward the left side of the graph. It'd be nice if it was further to the left. You can't make a lot of the pace graph without taking the course and terrain into account.

Then I look at the direction deviation histogram.

Direction deviation is a new feature in the latest version of QuickRoute. It measures the extent to which your direction varied from a straight line connecting two controls (or whatever two points you've marked on the track).

I think the direction deviation data for the entire course tells you something about the course, but not much about your run. The graph shows a fair amount of running that is well off the straight line. I know that. I ran the course. The coures-wide data hasn't told me much.

All three of the histograms are most interesting when you compare them with other races or other runners. I'm not going to do that today.

I like to take a look at the pace track for the entire course. I begin by looking for places where I was moving slowly.

On the map I've marked the places that jump out with letters.

But before looking at those points (which are marked by letters), note that the track doesn't line up especially well in some places. That means I didn't spend much time aligning the route (not true in this case) or that the map or the image of the map is skewed. In this case, the map itself is a bit skewed. It is an old map and was made in several pieces that were then put together.

Getting back to the places I was moving slowly...

A. A fairly short hill (3 meter contour interval) in an open area - why would I be going slowly? Because the yellow area isn't really open, it is ROUGH open and in this case it was full of chest high, grassy vegetation. I walked bits of the hill because it didn't seem like it was worth the effort to push through the vegetation.

B. Like A, a yellow area, but this time downhill. What was going on? Two things. First, the yellow was a bit rough. Second, I took a careful look at the map to sort out where I'd cross the stream. I slowed down a bit as I was looking at the map. If the terrain had been more friendly, I probably wouldn't have slowed as much while I read the map.

C. I fell where the track goes red. I fell forward and it was uncomfortable. The ribs hurt. Not really "hurt" more like unpleasant discomfort. Anyway, I took a while to get moving again.

One of my rules is that when I fall, I get up and take a careful look at the map. I try not to rush off quickly. Over the years I've made a lot of mistakes right after falling.

With QuickRoute you can figure out how long it took to recover and start moving well again. I'd been running for 20:15 when I fell down. In the next 30 seconds I only covered 30 meters. That's a few seconds on the ground and a few seconds looking at the map and starting to move. A minute after falling, I was only 80 meters up the trail and was just leaving the trail to head to the control. It only took about 30 seconds to cover the same distance on a trail on the way from 5 to 6. Falling down cost me 30 seconds.

Actually, the fall probably cost me a bit more. I wasn't running with much confidence for the next 5 minutes.

D. The slow pace doesn't jump out because it isn't red. But, I was running at a yellow-green pace through a flat and open area. My guess - I pushed a bit too hard on the previous leg and was forced to slow down a bit and recover. With QuickRoute you can check that by looking at the h.r. track. Sure enough, about half way between 5 and 6, my h.r. was up around 175. That's too high for me to maintain for long. I had to ease off the pace a bit. If I was race-sharp, I'd have felt that immediately and backed off quickly. I'm not race-sharp. So, I pushed my effort (while my pace was falling). The high h.r. didn't begin to fall until I'd passed the parking lot on the way to 8.

Maybe I can figure out how much time I lost because I didn't recognize my h.r. was too high. I used QR to figure out that it took me 1:17 to cover the distance where my h.r. was too high. Then I checked a similar part of the course where my h.r. was just a little bit lower. At that pace, I'd have covered the same distance about 20 seconds faster. So, failing to ease off right away probably cost me a good 20 seconds.

E. Uphill, in the woods. No wonder I was moving slowly.

For me, the next step in looking at a track in QR is to start looking at individual legs. That'll have to wait until later.

Back to okansas.blogspot.com.

posted by Michael | 6:15 PM


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