What is the thought process behind carbohydrate loading?

Carbohydrates seem to be a controversial energy source lately. With the "low-carb" craze continuing, what do you make of the traditional spaghetti dinner the night before a race?

First of all, I'm not a big fan of the low carb information that is so typical in our media right now. The goal should always be to have a balance of all three macronutrients (carbs, protein, fats) in your diet. Second, depending on what kind of performance you are expecting from your body, carbs are very important.

If you are planning to walk the half marathon, you probably don't need to make major changes to your day-before-the-race intake. Just continue eating a balanced diet and hydrating properly. However, if you are planning to run a minimum of 1-3 hours on race day, pay attention! At this level of activity, our body changes the types of fuel it can use. Muscle glycogen (energy stored in our muscle cells) and plasma glucose (energy in our blood from the food we've eaten) are the primary energy sources during this time frame. This supports the idea of having a meal rich in complex carbohydrates the night before a race and providing adequate complex carbohydrates the morning of the race. So enjoy your pasta!

-Nicole