Sunday, April 09, 2006

long run 18 miles

today's training: 18.02 miles, marathon course, 3:06:16 (10:20 min/mi), 151 bpm average/168 max

Ran the marathon course. Out and back (2x10.5 km) plus an out and back to the 4 km mark for 29 km or 18.02 miles total. STraM give 28.55 km or 17.74 miles (1.6% error).

Still very slow for the heart rate, but not as bad as 2 weeks ago. I averaged 146 bpm for the first 21km, which is the same as 2 weeks ago, but I finished the 21km a little over 8 minutes quicker.

I let myself drift higher today because I knew there was no way I could keep under 150 for 3+ hours. The rough gameplan was <150 for 10.5 km, <155 for next 10.5 km, <160 for next 4km and <166 for last 4km. I cheated a little and went to 160 and 166 about 1km early. Here are the semi-ugly results

  • 10:18/142, 0-10.5 km
  • 10:15/151, 10.5-21 km
  • 10:34/158, 21-25 km
  • 10:28/163, 25-29 km

All in all this doesn't compare too favorably to my long runs before the last marathon. My last 20-mile run was at 9:45 min/mi and 154 bpm average heart rate. This was 10:20/151. The course are similar in terms of ascent/descent per mile although the marathon course is unshaded and it's probably 20 degress warmer. Also, although it doesn't seem like much 3 bpm can account for a fair difference in pace (especially at lower paces), so it's hard to compare the two directly.

During the run today, I seriously considered just running the half marathon. If I had run a perfect pace at the marathon 4 weeks ago, there's a slim chance I could have made 4 hours. This time 4 hours seems impossible on a much tougher course in heat that is likely to be even worse. If I do the marathon, I should just aim lower and try to beat my last time (by going out slow and now walking at the end).

I can't quite let go of 4 hours though and would like to go out slower but give myself a chance at getting 4 hours by running negative splits if I feel good. The problem is I'm not sure I can even run 9:30 min/mi the whole way. If I ran the first half at 9:30, then I'd have to run the second at 8:48. Plus I'd have to decide to go to 8:48 with 13.1 miles left and risk crashing again. I could try 9:15 min/mi for the first 20 miles and then I'd have to run about 8:50 min/mi for the last 10K. The problem is that 9:15 min/mi on this course might be as hard as the 9:01 min/mi on the last course and we know how that last 10K turned out. Ugh.

I'm debating whether just to go back to my old lake loop for my long runs since it's shaded, has a softer surface (crushed gravel and dirt versus pavement) and has gentler hills. If I do go back to the marathon course, I'm not sure how to do the 20 miler. There was a 4 km marker but I don't think I saw anything else before 7.5 km. 2x10.5 + 2x7.5 = 36 km or 22.4 miles. I could also just use the mile markers and the .63 miles the footpod tells me it's to the first mile marker. 13+3.6x2 is about 20. Running over 20 sounds appealing because it's something I haven't done before in training and maybe it would help. Running 22 on the pavement might require too much recovery though. An alternative is 5 laps around the lake, which is 23 miles. Even at 10 min/mi though this is 3 hours and 50 minutes -- a long time running.

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