Tuesday, June 21, 2011

Hitting The Wall, Part 1

I'm familiar with hitting the wall in a marathon. In 8 marathons, I've hit the wall 8 times. Below is a graph describing my pace over the course of my fourth marathon.

This graph interests me for two reasons: 1) it's a visual representation of the wall, and 2) the winner also hit the wall, all though his wall was shorter, a little later and oh yea, his pace was shifted down much lower than mine. The winner (a skinny dude from Africa I'm sure) probably had about a 40-50 lb weight advantage on me.

Here's how I understand the typical solution for not hitting the wall:

  • muscles can only store about 20 miles worth of glycogen to fuel them.
  • any body has essentially an unlimited supply of fat to fuel muscles, but the body has to be adapted to burn fat.

  • muscles can be trained to burn fat by running a lot of mileage (glycogen depleted) at a slow aerobic pace (fat metabolism preferred).
Even though I've been aware of this potential solution, I've never really tried to implement it. I have no problem with running at a slow aerobic pace. It's the high mileage that has been a challenge. A typical base building program for me has been 20-30 miles/week over the course of a year, ramping up to 30-40 miles/week 4 months before the marathon, 40-50 miles/week 2 months before the marathon, peaking at about 60 miles/week a month before the marathon and tapering back down to 20-30 miles/week those last few weeks. This mileage hasn't been enough for me to adequately burn fat and not hit the wall.

Another potential solution for not hitting the wall is to carbo-load. I've tried this solution. I've eaten spaghetti the night before the marathon, drank Gatorades and consumed Gu during the marathon. The most positive effect that all these carbs seems to have on me is that they positively make me nauseated.

In Part 2 of this series is an alternative nutritional approach to avoid hitting the wall.

Click here for Part 2.


  1. Looking forward to the rest of the story (to paraphrase Paul Harvey)...

  2. It'll be a few days, but I think you know the rest of the story. Thanks for the inspiration.

  3. Sounds familiar. I've run 5 marathons and hit the wall the first 4 times. My solution involved a HR monitor. I ran 6 miles 3x a week at 70% HRR pace for 5 months. I ran at a 80% HRR during a half marathon a couple of weeks back. With the monitor, I didn't run the 70% runs too fast, and the 80% effort level was just right for race day. The result was I shaved 24 minutes off of my PR. Had I not picked up the pace in the last couple of miles, I felt like I could have kept going. You're quite a bit faster than me. I'm hoping to break a 4 hour marathon this year in Chicago.

  4. Stephen, I agree that HR monitors are useful. I've had one for years. Every now and then, I'll wear it to gauge my effort. So far, Chicago is my favorite city to run a marathon. I wish you the best with training.