Run, Sacramento

I need your help, please.

Help me figure out why I bonked so badly on yesterday's long run. It wasn't the leg cramping (thank goodness!) torture I've sometimes felt by going out too fast in the early miles of marathons.

Rather, it was that total fatigued state in which you feel as if someone wrapped you in a wet blanket and turned the road under your feet into wet concrete. This has never happened to me before on a mere long training run.

It hit at just past the 15-mile mark of an 18.6-mile base-building run. I completed the last three miles or so at a pace more than a minute slower than my usual long-run pace. I finished completely spent, breathing hard and feeling woozy. (Woke up this morning feeling fine, though.)

We've got some very knowledgable runners in Sacramento, so help a guy out, will ya? Let me lay out some facts to help you figure out why I bonked.

1. 18.6 miles is hardly unchartered territory for me. Already, in this training cycle for my early May marathon, I've done two 20-milers at an even pace and felt just fine.

2. I did not run the early miles at too fast a pace. It was fairly steady.

3. I had 32 ounces of Cytomax in my hydration pack (I used it all, needles to say) and gagged down a GU packet at miles 6 and 11.5.

4. I ran in the late afternoon. It was 58 degrees and partly sunny when I left midtown Sacramento and -- just a guess -- maybe 50 degrees and dark by the time I reached Davis.

5. I normally am an early-morning runner. I mean really early. Most days, this winter, I run at 5 a.m., when the temperature in Davis ranges between 35-45 degrees.

6. Here's what I ate at lunch and in the hours before running: 1 turkey sandwich on whole wheat bread, an apple, an orange, 1 peanut butter sandwich on whole wheat bread and an ounce of shelled sunflower seeds. Oh, yes, and a banana consumed 45 minutes before I ran. I drank a lot during the day. I'd estimate about 70 ounces. It was iced tea (caffeinated), not water.  

7. I've been fighting some sinus issues recently and took two Sudafed pills at 11 a.m.

8. Four days earlier, I ran all-out at a half-marathon in Davis, but my legs felt fresh all day Thursday.

OK, so, did I bonk because my body wasn't used to running when the temperature was warmer? I mean, geez, it was only 58 degrees, not like some heat wave.

Or did I bonk because I didn't fuel enough before the run (I'm used to waking up, downing a banana and taking off) during the day?

Or was it that I didn't drink enough during the run? (On my other 20-milers in this cycle, I drank less than 32 ounces and didn't even feel close to bonking.)

Or is it that I'm not as fit as I thought? (Always a possibilty, but then how does that explain other longer runs with no such issues arising?)

Or did the half-marathon take more out of me than I thought?

Or am I just an aging running hack who should hang 'em up?

I'm thinking it might be a combination of poor fueling throughout the day and not drinking enough during the early miles as well as that extra 10 degrees in the air temperature. Here's a primer by Runners World's Amby Burfoot on temperature and pace in marathon running.)  

I'm counting on you, the wisdom of the crowd, to help me out here. Please share your thoughts on why I bonked.

P.S.: Here's a well-written primer on bonking by a nutritionist writing in UltraRunning magazine.