It is not uncommon for athletes to tell us that they had heavy legs, low energy, and no ability to run at the end. Often times, a common theme from among these athletes is that they didn’t take in many (if any) carbohydrates during the run. There is a lesson to be learned here! And that lesson is: YOU NEED TO FUEL YOURSELF DURING TRAINING AND RACING TO PERFORM TO YOUR ABILITY!!! Here’s why!
First off “nutrition” is only of three critical elements of ‘fueling the body’ for endurance training and racing. The other two are HYDRATION and ELECTROLYTES. Hydration refers to water intake and electrolytes refer to our sodium, potassium, magnesium, etc. intake and balance. Nutrition provides the energy (calories) and is the focus of the remainder of this article.
Our bodies burn primarily use CARBOHYDRATE and FAT for fuel to power us through any activity. Most of us are well aware of how (and where) we store fat, but did you know that we store carbohydrate too? Our bodies store a finite amount of carbohydrate in the form of GLYCOGEN in our muscles and liver. We have around 2000 Calories of stored carbohydrate in our bodies when we are fully loaded. Now, it takes about 100 Calories to run a mile, so if you do the math, you will see that if you use only carbohydrate for fuel, you will run out of stored energy around mile 20 (hence, the dreaded WALL folks talk about between mile 18 and 22 in a marathon!).
Fortunately, endurance athletes train themselves to use fat for fuel as well as carbohydrates, so most folks don’t burn just carbohydrates. However, any time we exercise, we begin to deplete our stored glycogen. Now, when we our glycogen stores get close to empty, our muscles aren’t happy! You notice this in the “dead leg” feeling and the inability to get your legs to run (heck, you can hardly get your legs to move, let alone run!).
So what can you do to avoid this dreaded glycogen depletion??? You need to take in carbohydrates during training sessions! Our guts are highly adaptable and can be trained (just like our hearts and muscles). If you are not used to taking in any form of food during runs, begin with something simple like an energy gel or some sports drink (like Gatorade). I recommend starting with ~10-25 grams of Carbohydrates (which is between 40-100 Calories of carbohydrate) every 20-30 minutes. Start conservatively (with ~10 grams of carbohydrate). If you choose to use an energy gel, you will want to take some sips of water along with the gel. If you use a carbohydrate drink, you probably won’t need additional water.
How do you know if your fueling strategy is working? We want the following things to happen:
steady energy (no dips in energy or shakiness)
- no GI distress
- no gut cramping
- no muscle cramping
- no sloshing in the stomach (like you have water in your stomach and can’t get rid of it)
If you have any of these symptoms, then do one of the following:
change your carbohydrate source. If you used gels, switch to a drink or vise versa.
- Change the amount of carbohydrate you eat. Probably take in less.
- Slow down when you take in carbohydrates. Running hard AND trying to eat can cause problems
The good news is that the gut can be trained and you will adapt to taking in carbohydrate during runs.
I recommend using your fueling strategy for ANY run over 45 minutes. Take in 10-25 grams of carbohydrate at 20-30 minutes and continue this until the end of the run.