Giving your body the right fuel is critical when you are training to run a marathon

Whether you’re a seasoned marathon runner or just getting started, training for a half or full marathon is a challenge. But while preparing for the race may be tough, the food doesn’t have to be.

Remember, dieting is for losing weight — fueling is for marathon training.

Not everyone goes into marathon training free of injuries, health issues, or without dietary restrictions or choices. The sports nutrition experts at UPMC Sports Medicine break down a few health issues, diets, and training roadblocks to help you perform your best.

Training for a Marathon While Managing Diabetes

According to the Centers for Disease Control and Prevention (CDC), more than 9 percent of people in the United States have diabetes, which affects the way the body produces insulin and utilizes blood glucose.

When training for a half or full marathon, the goal is to keep blood sugar stabilized throughout the day and to be especially mindful of blood sugar levels before, during, and after training runs and workouts.

Training with diabetes isn’t a roadblock to a successful race or hitting a personal record; however, it requires more attention to food choices, especially carbohydrates. There are three types of carbohydrates:

  • Sugar
  • Starch
  • Fiber

Each of the three should be included in various ways, amounts, and at certain times. Carbohydrates should not be avoided when training, but need to be managed based upon training level, tolerance, and fasting blood glucose.

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Ketogenic Diet for Marathon Training

The ketogenic diet was originally developed for epileptic patients, and from there gradually made its way into the mainstream when the low/no-carbohydrate craze resulted in quick, short-term weight loss.

Now, the ketogenic diet is gaining traction in the exercise market as a way to enhance focus by using fat as the main energy source. This results in a greater reduction in body fat and sustained endurance during training.

The goal of a ketogenic diet is to achieve ketosis, a state in which the body produces ketones as an energy supply because blood sugar is low.

A ketogenic diet includes no more than 20 to 30 grams of carbohydrate per day. Most full-marathon runners should consume anywhere from 400 to 700 grams of carbohydrates per day.

Some of the main sources of fuel on a ketogenic diet include:

  • Non-Starchy Vegetables (Broccoli, Kale, Cauliflower).
  • Meats.
  • Nut Butters and Milk (Full-Fat Dairy).
  • Nuts and Seeds.
  • Fish.
  • Avocados.
  • Olives.
  • Eggs.

Foods that are not on the ketogenic diet:

  • Fruits (only exception is avocados).
  • Starchy Vegetables (Potatoes, Corn, Peas).
  • All Grains (Wheat, Rye, Oats, Corn, Barley, Rice and Sprouted Grains).
  • Quinoa.
  • Legumes and Soy.
  • Sugar.
  • Alcohol.
  • Fruit Juice or Dried fruit.
  • All Processed Foods.

“This is a diet I do not recommend, regardless of a person’s training status,” Lucchino said. “There is still limited research on the long-term use of ketogenic diets, with even less research specific to endurance athletes. Adding a variety of carbohydrates to your performance plan allows your body to get the glycogen and nutrients it needs to perform at the highest level possible.”

Food for Fueling Up For the Marathon

Fueling properly throughout your marathon training is what results in a successful outcome. Half-marathon and full marathon nutrition plans should not differ much at all in the quality of food; the biggest difference is the quantity.

Half marathon basics principles of fueling:

  • Balanced meal plates: 1/3 protein, 1/3 grains, and 1/3 produce.
  • Snacks: Moderate in protein and produce.
  • Beverages: Primarily water before, during, and after training.

Full marathon basic principles of fueling:

  • Balanced Meal Plate: 1/2 grains, 1/4 protein, and 1/4 produce.
  • Snacks: Primarily carbohydrates with moderate protein.
  • Beverages: Water during the day and sports drinks before, during, and after training, as well as carbohydrate-rich, post-workout smoothie or snack.

Race Fuel and Marathon Training

Intra-carbohydrate fueling (fueling during a training run or race) can be the boost a runner needs to improve their performance — or it could be your downfall come race day.

First, if you have used intra-carbohydrate sources during your training without any issues, proceed with using them during the race. Be sure to use the same brand and types you’ve used during training on race day, to prevent any unexpected reactions.

The standard recommendation for carbohydrate consumption during training is 30 to 60 grams of carbohydrate for every hour after the first hour of running.

That said, some half-marathon runners do not need to worry much about intra-carbohydrate fueling during training or on race day, but full marathoners most certainly do.

Carbohydrates intra-race can come in many forms:

  • Fruits
  • Fruit snacks
  • Gels
  • Gummies
  • Beverages

If you’re using a gel, gummy, or sports drink, look for brands with the following criteria:

  • Carbohydrates (at least two various sources of carbohydrates in the ingredient list).
  • Sodium (most abundant electrolyte lost during activity).
  • Minimal or zero caffeine.

Marathon Injury Recovery Foods

Injuries can occur at any time during your training. Always consult a sports medicine professional before continuing to train. During short-term recovery (10 to 14 days or less) dietary guidelines do change slightly.

“Our bodies need quality nutrition when in the injury state just as the active state. Yes, the body does a great job healing itself, but nutrients from food can decrease recovery time,” Lucchino said.

Half marathon:

  • During Training: 1/3 grains, 1/3 protein, 1/3 produce.
  • When injured:1/4 grains, 1/3 protein, and remainder of plate produce (fruits and vegetables).

Full marathon:

  • During training: 1/2 grains, 1/4 protein, 1/4 produce.
  • When injured: 1/3 grains, 1/3 protein, 1/3 produce.

Marathon Tapering Foods

After 12 to 16 weeks or more of training, every marathon participant looks forward to tapering, the period where the volume and intensity of training decreases.

Runners are sometimes confused about what to do with their nutrition during tapering. A percentage of runners keep everything the same, others over-load the carbohydrates. So what do you do? Two factors can change your nutrition during your taper:

  • Duration of taper.
  • Whether you’re training for a full or half race.

If you’re planning on a two week-plus taper, then your plate distribution will change from your standard plate to the lower carbohydrate based plate. If your taper is less than two weeks, continue to keep intact the same plate you had all training season.

If you’ve changed your plate during your taper phase, when should you begin to add your training plate back in?

A common, but disastrous mistake is adding a lot of carbohydrates back in the night before and morning of a race, also known as carbo-loading. Some runners can get away with this if they have experience from past races, and have a high tolerance to this method. Others may become sick to their stomach or extremely bloated.

Re-introduce your training plate two to three days before the race. This gives enough time to build up your carbohydrate stores and allows for any minor adjustments.

Also, if you gain one to two pounds the week before to the race, that’s a good sign. Filling your glycogen stores after depleting them for 12 to 16 weeks will result in increased intra-muscular water and carbohydrate stores.

Editor's Note: This article was originally published on , and was last reviewed on .

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