by Jana Peale
When it comes to the marathon, nutrition becomes a real concern. Maybe you have gotten away with just some water or electrolyte drink for a half you have done, but this event is double a half marathon! I cannot even go 3-5 hours without eating when I am completely sedentary. Add continued running for the amount of time and nutrition becomes vital.
About half of our energy while doing the long, slower runs comes from fat. Where does the rest come from?! Glycogen! We get glycogen from carbohydrates, which is why runners LOVE carbs. We also love electrolytes. Basically, electrolytes maintain electrical voltage across cells so that cells can function. Electrolyte depletion can at the very least cause muscle cramps and at the worst hyponatremia! Finally, the most obvious thing we need to take in while running is water. Our bodies are made up of about two thirds water. It pretty much makes everything happen. The main cause of mid-day fatigue is dehydration, so once again let’s think about what mid-run dehydration can do to us….
Ok, we know we need carbohydrates, electrolytes, and water while running longer distances. Now, how long is long distance? How much do I need? And where can I get these from while I am running?!
Carbohydrates: The body generally stores enough carbohydrates to last you two hours, but trust me you do not want to test that one! If you go a full two hours without taking in any carbs, you won’t have any energy. The rule of thumb is that whenever your run will take over an hour, you want to take in carbs. You will need a minimum of 50-75 grams an hour, depending on your size and how fast you are running. Take carbohydrates at about the 45 minute mark, then every 20-30 minutes after that point.
What to get your carbs from comes down to your personal preference. Most choose a gel, like GU or PowerGel because they are (relatively) easy to get down. However, there are other options. Most companies that make gels also make chews, which are basically a candy form of gel if you want to feel like you are eating something that more resembles food. Always read the labels to see if you are getting enough. In general these options have 20-25 grams of carbohydrates.
Also, when I say anytime you run over an hour, I mean every time you run for over an hour you want carbohydrates. I do not mean just on race day. First of all, you would have some awful, possibly dangerous training runs without any nutrition. More importantly, this is the time to experiment! Some gels or chews sit well in some stomachs better than others. Some have caffeine. Some taste just down right awful. The last thing you want is for something as preventable as the wrong for a gel to ruin the event you have been training so hard for!
Electrolytes: First when I say electrolytes, I do not mean just sodium and potassium. They are the most important, but we also need chloride, calcium, magnesium and if we want to get really technical, bicarbonate, phosphate, and sulphate. Now, how much you need is dependent on the climate and you. If you are a really good sweater and running in the middle of July, you are going to need a lot more electrolytes than someone that does not sweat that much and is running in December. To give you numbers, the range for sodium is 500-1000 mg per hour. You do not need as much, but you should take in the other vital electrolytes.
Carb sources will almost always have some electrolytes, but always read the labels to see if they have enough. Most do not. There are plenty of supplement options. You can take pills, add a electrolyte solution to your water, or use an electrolyte tab to your water.
Water: Water intake is also sweat dependent. People need anywhere from 12-30 ounces of water per hour. This is also something you really want to train for because at first it can feel pretty uncomfortable to put that much water in your stomach while running. You always want to take water with your carb source, so start there and work your way up to taking in more water while you run.