Saturday, August 18, 2012

Recent 5K and Revelations

Last weekend we ran the Hank Aaron State Trail 5k. We hadn't done a 5k in a while and this was a lot of fun. I went with the completely unrealistic idea that I could finish in under 20 minutes (my best recorded time was 23:xx, and my suspicious personal best in training was 20:40 last summer). Anyway, I finished in 22:40, a cool 7:19/mile. I should be happy with that... it's been a while since I ran that fast. But as a consequence, I was extremely sore the next day. Haven't been so sore from such a short distance in quite some time.

I haven't been running much recently (until today, but that'll come later), but I have been doing body awareness exercises from Running with the Whole Body. I am loving the program, but I have yet to really "run faster with less effort" as it promises. But I am patient and I know that all comes in time. I do feel my form improving, though. I've also been perusing The Big Book of Endurance Training and Racing. It's really interesting, and really complete. I had a big revelation from it: carbo-loading is a lie. Especially for a properly aerobically trained athlete.

For long endurance runs (anything longer than a sprint, really), you're burning fat as fuel, not sugar. For runs over two hours, less than one percent of your energy expenditure will be from sugar. The less aerobic base (meaning the ability to run at satisfactory speeds with a heart rate of 180 minus your age, give or take), the more you'll rely on sugar to take you faster. So burning fat is the whole idea. I knew that, but I didn't know what it took to truly train your body to run on fat. Moreover, I didn't realize that eating a lot of sugar pre-run will actually discourage your body from burning fat. So even if you're well aerobically trained, it seems like too much sugar can actually sabotage your efforts. Wow. Meanwhile, here I was gobbling up pasta and slurping energy gels, just like a lot of other people.

I went out for a run at 4:40 this morning with a heart rate monitor, my new handheld water bottle and a bean–avocado burrito. I had it in my head that I'd go 30 miles, but there were a few reasons that didn't happen:

  • My ankles were starting to kill me
  • I planned my route with a few passes by my house in case I'd have to get more food/water, change shoes, etc. One of those returns was at Mile 22.5. 
  • I hadn't run more than a few miles at a time since the marathon three weeks ago (does that matter? I'm unsure)
I gave it up at 22.5 miles because I didn't want to risk hurting my ankles, and because I felt my form starting to slip. Note to self: Do ankle strengthening exercises. BUT I was super impressed with myself because I did not feel exhausted like I usually did at that point in a marathon. I ended up doing it in 11-minute miles, staying within the aerobic HR zone of 145–155 is much as I could. I think for a lot of it I was actually closer to 140 because I was planning on going 30 miles and didn't want to get exhausted. Even so, I know now that my aerobic base needs some work. FINALLY some answers as to why my marathon performance was always a bit sour. 

The current debate: Do I run an October marathon, or do I devote the next several months to training up my aerobic base and come in strong for Disney World this January? I'm opting for the latter, because I think it's smarter... but I really wanted to do Bilbao. Maybe I'll do the half marathon?

No comments:

Post a Comment