What Diet is Good For a Marathon?

Nutrition is often an overlooked element of marathon training. The right nutrition plan will make those long training runs seem much easier!

Food is your source of energy. All food is composed of carbohydrates, proteins, fat and fiber. Carbohydrates are tied to energy production, complete proteins are tied to tissue repair and building, fat provides body fuel and fiber is roughage.

Most foods will have trace amounts of all these macronutrients, but each is typically rich in one. ALL are needed in your diet.

Carbohydrates

Your body burns carbohydrates more efficiently than fat or protein. Consider increasing your carbohydrate intake to 60-70% of your daily food intake.

Runners benefit the most from the amount of carbohydrates stored in the body. Carbohydrates yield more energy per unit of oxygen consumed than fats. What this means is that you get more energy for running when your body burns carbohydrates than you do when your body burns fat or protein. Because oxygen often is the limiting factor in long duration events, your body will find it easier to use the energy source that requires the least amount of oxygen per kilocalorie of energy produced. (energy is measured in kilocalories)

Your body produces energy by converting carbohydrates into glucose. When you are exercising at a moderate pace, carbohydrates provide 40 to 50 percent of your energy requirement. As you start running harder, carbohydrates provide a greater percentage of your energy requirements. It is difficult for your body to break down protein and fat into glucose to provide energy. Therefore your body first burns carbohydrates. The harder you work, the harder it becomes for your body to devote energy for breaking down protein and fat. That energy could be used to propel you forward in the race.

Best sources of carbohydrates for your marathon training

Carbohydrate needs are commonly based on the runner’s body size and activity level. Runners engaged in moderate-duration, low-intensity exercise require 5-7 g of carbohydrates per kilogram of body weight. By contrast, those participating in long-duration and high-intensity exercise require 7-12 g of carbohydrates per kilogram of body weight.

All carbohydrates are not created equal.

Best sources of carbohydrates in your diet

  • Fruit,
  • vegetables,
  • brown rice,
  • enriched whole-grain breads,
  • whole grain cereals,
  • rolled oats,
  • beans,
  • legumes, and
  • sweet potatoes

(Note: Cheetos, cookies and tortilla chips are not on the list.)

Fat

The next macro-nutrient to be used by the body during exercise is fat.

Fat is not the enemy. Fat created from an excess of cheetos is. (Remember that excess of any macro-nutrient – carbs, protein, fat – is turned into fat.) For moderate exercise, about half of the total energy expenditure is derived from free fatty acid metabolism. If the event lasts more than an hour, the body may use mostly fats for energy. Using fat as fuel depends on the event’s duration and the runner’s condition. Trained athletes use fat for energy more quickly than untrained athletes. (This is one of the adaption mechanisms of the long run in marathon training.)

Best sources of fat in your diet

  • Nuts
  • Seeds
  • Nut butter
  • Fatty fish
  • Fish-oil supplements
  • Flaxseed oil
  • Safflower oil
  • Canola oil
  • Sunflower oil
  • Corn oil
  • Avocados
  • Egg yolks

Protein

After carbohydrates and fats, protein provides energy for the body. You also need protein to repair muscle tissue that is damaged during exercise. While exercise may increase an athlete’s need for protein, most Americans tend to eat more than the recommended amounts of protein.

A protein intake of 10 to 12 percent of total calories is sufficient. Most authorities recommend that endurance athletes eat between 1.2-1.4 grams protein per kg of body weight per day. Remember, extra protein is stored as fat.

It’s doubtful that you will need extra protein, what is probable is that you need to be more mindful of where you get your protein.

Women trying to lose weight by cutting calories often forego healthy protein sources for bagels. Don’t get me started on my “bagels are empty calories” rant; for now, all I’ll say is protein-rich foods include lean pork and beef, poultry, fish, eggs, beans, tofu, and low-fat dairy products. Include lean sources of protein in your marathon training diet.

Best sources of protein in your diet

  • Lean pork and beef
  • Poultry
  • Fish
  • Eggs
  • Low-fat dairy products
  • Broccoli
  • Beans
  • Corn

Fiber

Fiber helps the body stay healthy and may prevent heart disease. Getting enough might be easier than you think.

Soluble fiber, which is found in oats, barley, beans, apples, oranges and other fruits and vegetables, may help prevent heart disease by lowering LDL, or “bad” cholesterol levels. Set a goal to eat 20 to 35 grams of fiber every day. The best way to do this is to consume a wide variety of whole grains, nuts, seeds, beans, fruits and vegetables.

Fiber also keeps the bowels regular. This is key to avoiding discomfort on your long training runs.

Best sources of fiber in your diet

Include more fiber in your eating plan by adding vegetables to stews and casseroles. Add oats to meatloaf, breads and cookies. Fruit on cereal, as a snack and in salads are other options.