Another great Sunday run. My iPod shuffle again had a great sense of timing and played Jackson Browne's Running on Empty as I finished.
Turns out it wasn't windy yesterday. Today was windy. The lake had white caps for most of the run and when going over the dam the first time, without the cover of trees, I found my first step landing about a foot-and-a-half to the right as the wind blew me sideways. Wow.
My split times/average heart rates for the three laps plus out and back were 45:20 (147), 44:25 (152), and 42:14 (160) for the three lake loop and 17:27 (163) for the rest. I was still tired from yesterday, but thought today was a good day to just put one foot in front of the other. After all, I know I'll be tired at the end of the marathon. I set the max on the heart rate alarm at 155, but started to bump against it around mile 9. Sometimes your "gear" is a few bpm above where you're shooting for. For example, yesterday during the staircase intervals I just tried to find the next natural gear, because there wasn't a comfortable way to run example 8:30 min/mi (or 8:00, etc.).
Notice I got a little frisky a couple of minutes into the third lap. I thought I'd feel for a somewhat faster gear and see where that fell with marathon pace. If you use the 4.65 miles per loop average that STraM gave today, I ran the 3rd lap at 9:04 min/mi pace. It was pretty comfortable. I wasn't able to breath comfortably with a 4-4 breathing rhythm though. I fell into 3-3 breathing after a while although 3.5-3.5 would have been perfect :-)
Last year I erroneously thought 2-2 breathing was 2 strides in and 2 strides out (actually 4-4 breathing) instead of 2 steps in and steps out. When I'd have to breathe faster than that I took it as a sign I was struggling. I believe I did the whole marathon with 4-4 breathing. I'd also heard that if you couldn't do 3-3 breathing during your long runs it was a sign you were going too fast. I'd try to force myself to do my version of 3-3 breathing, which was actually 6-6.
Bob Glover's Competitive Runner's Handbook says a "3-3 pattern is good for very easy days" and the "3-3 ratio may be beneficial for the first few miles of a marathon, but for most racing the 2-2 pattern works best." What's the matter with me? Today I was doing 3-3 breathing at over 80% of my max heart rate 15 miles into the run. I wouldn't call it a "very easy day." As I said before, it took me about a mile and a half into my 10K to force myself to use 3-3 breathing. It's not like I have super lung capacity or anything. According to the printout from the breathing test my doctor did after I got over bronchitis, my lung capacity was 88 percent of predicted for my height, weight, age, and gender.
Anyway, maybe I've become something of a wimp expecting things to be too comfortable. I'm considering going back to the strategy I used in my first race last spring before I "knew" anything -- start slow and then keep passing people until I'm breathing as hard as the group around me. Well, it's a thought anway.
Lactate threshold update. Willem graciously analyzed my data (for which I'm much appreciative) and after tuning STraM (by fixing my breathing rate) and using some of the Suunto Swiss Army Knife's expert tuning boxes, he found my heart rate at lactate threshold to be 173 bpm. He also interpolated between the lap speed to get 7.3 mph or 8:13 min/mi pace. Marathon pace would then be 8:39 min/mi. Still pretty close to the 8:29 min/mi McMillan predicts. 8:45 min/mi would knock an hour off my first marathon, so I'd be happy with that. I haven't firmed up my exact marathon goals though. I'm toying 4 hours as my realistic goal with 3:50 or maybe 3:45 as my dream goal. Here's Willem's handiwork.
A recap of what I did wrong in the analysis:- I should have set the watch to 2 second time resolution from the default 10 seconds.
- I should have used SAK to come up with better personal parameters (mainly breathing) and then fed those back to STram and reanalyzed the data.
- I should not have read the heart rate at lactate threshold by looking where the cloud of red dots intersects VO2 at lactate threshold (VO2.LT). At higher VO2 the heart rate shifts upward (possibly because of lactate accumulation) and you should look at where the line extrapolated from lower intersects VO2.LT.
- I should not have included the low heart rate points (from my jog to and from the track).
I realized I didn't try to back out heart rate at marathon pace yesterday, so I'll try my hand today. 8:39 min/mi is pretty close to 8:41 min/mi (166 bpm). It's less than a tenth of the way to 8:20 min/mi (172 bpm) so we'll call my heart rate at marathon pace 166-167.
By the way, I came to this conclusion by feel during my marathon pace run (15 miles with the last 12 at marathon pace) about a month ago. I ran at about 9 min/mi on a relatively flat course during the marathon pace portion. In retrospect I think the calibration factor was about 1 percent too high so call this 9:05 min/mi pace. As the graph shows I started at about 160 and drifted up to 166. I figured at the time I could probably start the marathon at 166 (after a few miles of warming up) and drift into the 170's by the end of the race. I assume that my lactate treshold heart rate drifts as well, so I wouldn't be "over the line" with such a strategy.
T6 logbook and STRaM distance differences. I did three laps plus a little out and back until the foot pod said I'd gone 16.01 miles. Viewing the logbook on the watch showed the laps as 4.70, 4.67, and 4.67 miles, and the little out and back as 1.97 miles. After STram was done it had cut my 16.01 miles to 15.87 and reduced the splits to 4.67, 4.64, 4.64, and 1.96 miles.
Section 7.3.5.1, "Differences between the DISTANCE values," of Willem's document seems to address this, but I don't think it accounts completely for what I'm seeing. If I'm reading correctly, STRaM only reports the distance at the sample at the time before the mark, which could be up to 10 seconds old. The logbook also reports with 1 meter precision while the marks in STraM only have 10 meter resolution. Still this doesn't seem to explain it. Ten meters is less than 0.01 miles and even at 8 minute per mile pace 10 seconds is only .02 miles. 16.01 minus 15.87 is .14 miles. Around a .1 mile difference between the t6 logbook and STraM is typcial for my long runs. Willem's document says he doesn't see differences of more than 20 meters. Since he's using only metric units, is it possible this is only seen with English units? I'm sure there's something I'm missing and that it's somewhere I haven't found on Willem's web page. Perhaps I should run with 2-second resolution and see if the magnitude of the STram-logbook difference changes just to experiment rather that read :-)
I don’t know where I’m running now, I’m just running on...
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