If you’re a long distance runner, there’s a good chance you’ve had the unpleasant experience of “hitting the wall.”  Not literally of course, but it can be just as painful and unnerving as if you really had. 

Anyone who has trained for a marathon has heard of the term “hitting the wall.”  Sometimes also referred to as “bonking,” hitting the wall is when a runner depletes out their glycogen which is the body’s storage form of carbohydrate.   The liver and muscles store glycogen and is therefore known as muscle glycogen or liver glycogen.  Glycogen is an important source of fuel used to directly produce ATP (energy) but also allows the body access to fat as a fuel source as well. 

An experienced runner will pretty well know what is happening when they have reached this threshold.  It’s not the same thing as feeling a painful cramp in the calf caused by lactic acid build-up or the deep muscle pain sometimes caused by downhill running.  Anyone who has hit the wall will have their own unique description of what it was like.  But generally, it is like an entire collapse of the body – many describe it as if the legs turn to jelly lacking support while the brain and body both turn into mush.  Pain is involved as one’s body feels like it’s going to fall apart with each stride while every single muscle is screaming for fuel.

Doesn’t sound like much fun, does it?  This depletion of glycogen stores can be avoided however.  To understand what is happening and more importantly, how to never let it happen, it’s necessary to have an idea of how glycogen is imperative for long distance runners or bicyclists.  Our body stores glucose for energy in the form of glycogen.  Glucose comes from the breakdown of the macronutrient carbohydrates which are found in all plant-based foods and milk and yogurt. 

Think of the necessity of putting gasoline in your car.  If you want to go from point A to point B, you better fill up the tank with enough fuel to make that happen.  Our muscles and brain operate and won’t function without glucose.  When our bodies run out of glycogen stores, our liver then goes to plan B which is to convert fat into glucose.  The only problem is this process requires oxygen and when runners are completing a marathon most of the oxygen available is being used up not leaving enough to complete the deal.  This is when “hitting the wall” can happen and what leads to muscle cramping, systemic pain and exhaustion, mental confusion and lack of energy.

How to prevent hitting the wall

Now that we have a better understanding of what the term hitting the wall means, here are two very important steps to take to never let it happen to you:

1. Carbs are your best friend

When preparing for a full 26 mile marathon or even a half-marathon, preparation is required.  Of course there is the hours and hours of running time involved but don’t neglect the importance of what you are eating.

About a week before the race, start with a high-carbohydrate diet by consuming 70 percent of your food from carbohydrates which is equivalent to 8.5 grams per kilogram of body weight.  This can increase muscle glycogen by as much as 150 percent which is vital for boosting endurance.  This carb-loading method can aid endurance by putting fuel into the muscles. 

The brain also needs carbs too but the brain only burns glycogen stored in the liver.  By loading up on carbs the week prior to the event, this can prevent depletion of glycogen from the muscles and brain reducing the likelihood of being able to avoid fatigue while still having the motivation, decision making and agility to continue the race without hitting the wall.

2. Protein is also key

Adequate protein is another macronutrient recognized as a strong contender in preventing a bonking experience.  Protein strongly stimulated insulin release.  Insulin speeds muscle cells’ absorption of blood glucose.  So when you are running a race burning up those stored carbs or glycogen, protein is helping to speed up the entry of blood glucose to keep you adequately fueled to be able to cross the finish line without collapsing.  Consume between 25-30 grams of protein at each meal.

Take away message

For anyone considering signing up for a long distance race – running or cycling – never underestimate the importance of nutrition and hydration when training.  Ignoring their fundamental role in helping you finish the race in fine form, is a mistake you want to avoid.