How to Avoid the Nutrition Wall E-book by Coach Greg McMillan

As a runner who is still training and competing, with an exercise science background, and the real-world application of coaching athletes, Coach Greg McMillan is bringing three perspectives together to help people figure out how to get from where they currently are as a runner to reaching their goals.

In this FREE E-book, Coach Greg highlights his training and nutrition strategies to help runners avoid hitting the wall.


How to avoid the wall is a topic that’s top of mind for marathoners, distance runners and endurance athletes. When the first running boom happened in the 1970’s everyone wanted to be like Olympic gold medalist Frank Shorter and run the marathon. As marathons grew in popularity, people began to experience a significant decline in pace, usually around the 18 to 22 mile mark. The fast guys at the front of the pack would go from running 5 minute miles to running 7, 8, 9 minute miles or even walking!

Hitting the wall is the overall experience of complete fatigue where it’s impossible for you to maintain your race pace. You’ll often hear athletes refer to this feeling as “bonking”. You might have the desire to go, but your body just won’t go and you slow down to a walk, walk/jog, or very slow run for the duration of the race. This large change in your pace due to overwhelming fatigue is what’s known as the wall or bonk.

It’s easy to hit the wall. Just don’t ingest any carbohydrate and run for a long time and you will eventually hit the wall. That wall could be lower blood glucose or it could be a lower muscle glycogen store. For a lot of us, lower blood glucose is the first thing that we experience. The main reason is that your brain uses glucose as its primary fuel source and has a very tight range of blood glucose levels that it likes, so if you get too high or too low it sends out reactions to deal with that.

As an exercise physiologist I’ve always been interested in understanding what’s going on inside the body that causes this wall. Early on, researchers and exercise scientists set up experiments that forced people to run on treadmills until they hit the wall and they were able to identify three big potential causes.