Carbohydrates for Marathoners Part 2

By Ben Connelly

I wanted to follow up last week’s post by delving deeper into some specifics on carbohydrate consumption during marathon training. Carbohydrates are crucial to fueling long runs and recovery (for every athlete, not just runners). But the average American runner probably eats enough carbohydrates to meet those needs. However, they may not be consuming the right type of carbohydrate.

During the high volume of marathon training, runners need to pay more attention to their diet to ensure they are getting the macronutrients and micronutrients they need to recover. But as I mentioned last week, during tapering, runners should begin shifting their macronutrient balance towards carbohydrates. When running peak mileage, runners may need to focus more on protein and micronutrients. But as the days count down towards race day, marathoners can start replacing some protein (and fat) with carbs in order to build up their glycogen stores.

Type of Carbohydrate:

For simplicity’s sake, I will not go into too much scientific detail here. I realize that I am heavily simplifying, but the rules of thumb I provide should be enough for most runners’ purposes. 

We can divide carbohydrates (roughly) into complex carbs and simple carbs. If your goal is to build up glycogen stores, or recover from workouts, you need complex carbs. On the other hand, if you need instant energy, you want easy-to-digest simple sugars – which are contained in gels, gus, sports drinks, chews, and all the other products runners consume during races. 

Key Takeaway: During a long run or a race, you want the simple sugars found in gels or gus (or your favorite marathon fuel of choice). At all other times, you want complex carbohydrates. 

Given that you still need to avoid micronutrient deficiencies, you should seek out sources of complex carbs that are also micronutrient-dense. A good start is to eat your vegetables. Most vegetables are sources of carbs, and contain high amounts of vitamins and minerals. 

Other top sources:

• Quinoa: nutrient-dense and also a source of protein
• Oats/oatmeal: not the instant, sugary kind
• Rice
• Potatoes: Although they get a bad rap, potatoes are actually very high in vitamins and minerals
• Sweet Potatoes: More potassium than a banana. Which means sweet potatoes (and white potatoes, too) can help you replenish electrolytes following a hot run.
• Turnips, parsnips, and other root vegetables

Occasionally, you can also indulge with bagels or pasta or bread or corn.

Shifting Ratio:

If you count your macros, you will find it easy to increase the ratio of carbs to protein and fat in your diet. For everyone who does not, try the following rules of thumb:

• Try counting calories and macros (protein = 4cal/g, carbs = 4cal/g, fat = 9cal/g, and alcohol = 4cal/g) for a week and see what you learn about your diet
• Simply start paying attention to the food you eat: read nutrition labels, understand the macronutrient (and micronutrient) composition of the foods you consume – even without counting calories, you will learn a lot
• Shift your diet away from high-fat, high-protein foods, towards carbohydrates: more vegetables and fewer nuts, meats, eggs, dairy products, oils, etc.
• Make sure vegetables and foods like rice and potatoes take up larger portions of your plate than previously. Continue eating some meat and eggs, but in smaller portions.
• Replace high-fat snacks with vegetables and high-carb foods: trade your nuts for carrots and your cheese for chopped sweet potato

The more you pay attention to your diet and the more you learn about nutrition, the easier they will be to control. With some mindfulness and some reading of nutrition labels (and maybe a tiny bit of math), you can easily eat in a way that fuels your training and meets your race day goals.