Marathon and Half-Marathon

by Marnie Caron

  • Fainting

  • Fatigue

  • Weakness

  • Cramping

  • Nausea

  • Vomiting

  • Bloating and puffiness in the face and fingers

  • Loss of consciousness

  • Fluid in the lungs

  • Seizures

  • Coma

  • In severe cases, death

  What about overhydration?

  One of the problems with the growing number of athletes who are taking a run/walk approach to the marathon is the increasing rate of hyponatremia, or overhydration. As University of British Columbia sport medicine physician Dr. Jack Taunton points out, “The big concern that we are starting to see in marathoners who are walking large portions of the event is overhydration. Basically, these folks are walking through the aid stations, ingesting too much water, and end up with hyponatremia. It can be and has been fatal.”

  Hyponatremia is a shortage of sodium in the blood. This state occurs when runners sweat excessively, lose too much salt, and drink excessive amounts of water, which then dilutes the blood’s sodium content even more.

  Why has overhydration become such a concern?

  “There is an obsession that people have in this current society with drinking fluids and being concerned about dehydration. Everyone seems to have a water bottle on their desk or with them at all times,” says Dr. Taunton. He finds at least part of the reason for our concerns in sport medicine, and in the American College of Sport Medicine guidelines, which became increasingly aggressive in terms of encouraging people to drink more and more fluids. Now we’re starting to see marathon organizers taking two and three aid stations out of the races in order to reduce the risk of people taking in too much fluid.

  For beginning runners, hyponatremia is a significant concern, but it’s not a problem for the very fast. When elite runners are running fast, their gastrointestinal systems’ absorption rate is impaired. This means “it is virtually impossible for those finishing a marathon in under 3 hours to take in too much water,” says Dr. Taunton. However, when people are moving at a shuffle pace, they haven’t shunted the blood supply away from the gut to the exercising muscle. Your body still has the capability of absorbing a great percentage of the water you drink, so you end up increasing your total blood volume and diluting your sodium sources. This is when you run into problems. This is why it’s essential for beginners to play close attention to their fluid intake and remember to alternate water with electrolyte solutions along the way.

  To avoid overhydration, consume an average of 4 to 8 oz. (120 to 240 milliliters) of sport drink every 15 to 30 minutes during your race. You may want to increase your salt intake slightly 2 or 3 days before the race; sprinkle a little salt on your food once or twice a day, hydrate with a sport drink the day before, and enjoy cereals and breads as part of your carbohydrate-loading plan.

  Getting Your Nutrients

  Vitamins and minerals

  Regardless of whether you’re a vegan, eat organic food regularly, or knock back a sirloin every few days, your cells are looking for some key nutrients to do their job. The human body uses carbohydrates, protein, and fat from food to fuel itself, and in order for the metabolic processes to work properly, it requires vitamins and minerals. Here are a few tips on vitamins from Parsons:

  • You will need fewer vitamin and mineral supplements if you have a balanced diet and take in an adequate amount of calories.

  • Milk, egg yolks, and vegetables are a good source of vitamin A.

  • Many fruits and vegetables provide vitamins B and C.

  • Meat, whole grains, leafy vegetables, soybeans, poultry, and fish offer B vitamins.

  • Vitamin D is found in egg yolks, fish oils, canned sardines, fortified milk, and soy-milk products.

  • Wheat germ, sunflower oil, and whole grain cereals have vitamin E.

  • Vitamin K is found in vegetables, especially in green, leafy ones.

  • Calcium is found in dairy products, fortified soy products, fortified orange juice, almonds, and oranges.

  • Meat and alternatives, enriched cereals, clams, and lentils offer iron.

  Runners need carbohydrates

  If you’re a distance runner, you need a fair amount of carbohydrates in your diet. Different from proteins and fat, carbohydrates are quick and easy to break down and offer an almost immediate source of fuel. Extra glucose can also be stored in your muscles and liver as glycogen, the main source of fuel for muscle movement. Human beings have a low capacity for storing glycogen, which is why you need to replace it daily.

  The Glycemic Index (GI) was originally developed for people with diabetes; it classifies carbohydrate-containing foods by how much they raise blood sugar levels compared with a standard food. A food with a high GI raises blood sugar levels more quickly than a moderate or low glycemic food. Eating foods with a low GI may help to provide lasting energy for long runs and control your appetite.

  The main difficulty with using the GI is that the index value remains true only if the food is eaten in isolation, but this is not practical, because food is mostly eaten in mixed meals. Dietitians say this doesn’t mean the GI has no value, just that it is a complex approach. What is most important is that, as a runner, you choose quality food sources of carbohydrates such as whole grains, fruits, and vegetables to fuel your body.

  Allow time to digest food. Approximate digestion times: 1–2 hours for carbohydrates, 2–4 hours for protein, 4–6 hours for fats.

  Protein

  Dallas Parsons encourages runners to include protein in their diets: “Although carbohydrates are the main staple of a runner’s diet, protein is also very important for the growth, maintenance, and repair of muscles and other tissues.” Protein is needed for the formation of hemoglobin, which carries oxygen to working muscles and provides support for the immune system. Protein also slows digestion and increases people’s satisfaction levels after finishing meals. The best choices for protein sources include lean red meats, fish and seafood, poultry, beans and lentils, tofu, eggs, and low-fat dairy or soy products. Aim to include one of these foods in each main meal.

  Aim to choose these sources of carbohydrates most often

  • Grains such as brown rice, quinoa, amaranth, kasha, and wild rice

  • Whole and sprouted wheat bread and whole wheat pasta

  • High-fiber and whole grain cereal

  • Brightly colored fruits and vegetables

  • Dark-green and leafy vegetables

  Good and bad fat

  We have all read about the hazards of too much fat, but too little fat or none at all is also bad. The best or healthiest sources include omega-3 fatty acids. These are essential nutrients that help your body to function properly. Salmon, tuna, flaxseed oil, canola oil, soybean oil, fortified eggs, and dairy products are just a few of the options for including omega-3 fatty acids in your diet. Other healthy fat choices include olives, nuts, seeds, vegetable oil, and avocado.

  One serving of fat equals 1 teaspoon of oil. Try to limit your amount of added fats to three to six servings per day.

  Bad fats such as trans-fatty acids should be avoided or consumed only on rare occasions. Trans-fatty acids are commonly found in highly processed food products, including some margarines, and usually in fast foods and snack foods as well as in commercially baked cookies, muffins, and cakes. Look at the “Nutrition Facts” label and aim to get as close as possible to “0 trans fats.”

  The vegetarian runner

  Being a vegetarian means different things to different people. Some vegetarians eat fish and chicken; others abstain from all animal products, including dairy products. Regardless of the type of vegetarian you are, the basic principles of healthy eating remain. Remember, it’s all about a well-rounded, wholesome diet that remains flexible to allow a moderate amount of “treats.” Vegetarians who don’t eat any seafood or meat can easily miss out on some vitamins and minerals that are difficult to fi
nd in a strict vegetarian diet. These nutrients include protein, calcium, iron, zinc, vitamin B12, and vitamin D. Fortified foods such as breakfast cereals, textured soy products, and soy beverages provide many of these key nutrients. A multivitamin and mineral supplement would also be a worthwhile investment. Alternative protein sources such as tofu, beans, lentils, nuts, seeds, soy beverages, and meat analogues provide adequate protein when eaten in the correct amounts.

  If you are unsure whether you are meeting all your energy and nutrient requirements, or if you need additional supplementation, consult a registered dietitian. If you are experiencing unusual fatigue, you should make an appointment to see your physician to have your iron stores (ferritin) checked.

  Daily Meal Planning and Calorie Levels

  Now that you have read about the nutrients your body needs to be well fueled for running, your next questions might be: how do I get all this good nutrition in and how much do I need? It may sound more complicated than it is. Says Dallas Parsons, your daily energy requirement (caloric needs) is determined by four main factors: resting metabolic rate, thermal effect of food, daily activity, and purposeful exercise. As a runner, 55 to 60 percent of your calories should come from carbohydrates, 15 to 20 percent from protein, and the remaining 20 to 25 percent from fat. Despite all the numbers and serving recommendations, there is no prescription diet that meets everyone’s needs. Always adapt recommendations to your personal preferences and requirements.

  Insights into smart meal planning for runners

  • These are essential kitchen tools for a busy athlete: indoor grill, steamer, and slow cooker.

  • Make a 1-week meal plan. Figure out how many dinners and lunches you need. Think about your training and whether you need anything special, such as sport-drink powder.

  • Buy a small chalkboard for the kitchen and use it for a running list of foods that need to be replenished.

  • Keep your kitchen well stocked with foods that are handy in a pinch, such as frozen meats, breads and vegetables, canned beans, tomato sauce, pasta, and dried fruit.

  • Go shopping every week for fresh fruits and vegetables.

  • Make double the recipe and freeze leftovers, or take them for lunch.

  • Scout out some simple recipes. Ask your running mates for their favorite quick recipe.

  • Pack lunches, snacks, training food, and fluids the night before.

  • Keep a food journal to ensure you are eating a complete and adequate diet. Reflect on your entries for clues on how to improve your eating habits.

  Estimating your daily calorie needs

  Calories

  30–32 cal/kg (2.2 lb.) body weight per day on rest days 33–38 cal/kg body weight per day on 1-hour running days 39–43 cal/kg body weight per day on 2-hour running days 44–50 cal/kg body weight per day on 3-hour running days

  Carbohydrates

  4–5 g/kg/day on recovery days

  5–6 g/kg/day for 1 hour of running

  7–8 g/kg/day for 2 hours of running

  8–9 g/kg/day for 3 hours of running

  Protein

  1.0–1.2 g/kg/day for an adult runner to maintain mass 1.2–1.4 g/kg/day for an adult runner building muscle mass Note: 2.0 g/kg/day is the maximum usable amount of protein for adults.

  Fat

  Minimum 1.0 g/kg/day for an adult runner, depending on energy needs

  Table 9

  Food-Group Servings Based on Calorie Level

  The Basics of Eating for Training and Competition

  Before running, why should I eat?

  Eating before running has three functions: to top up muscle, liver, and glycogen stores; to ensure adequate blood sugar levels; and to prevent hunger before and during exercise.

  What runners eat is just as important as why they eat

  Try to choose lower-fiber, carbohydrate-rich foods such as breads, grains, cereals, fruits, and vegetables. Include small amounts of protein. If, for example, you eat 2 to 4 hours before you run, sources of protein might include 2 ounces (56 grams) of lean meat, 2 tablespoons (30 milliliters) of peanut butter, 3/4 cup (180 milliliters) of low-fat yogurt, 1 cup (250 milliliters) of milk or 1/2 cup (125 milliliters) of cottage cheese, and 1 egg. Avoid high-fat foods. On race day, eat only familiar foods. Try out your pre-race meal during training to ensure that it agrees with your stomach. If you suffer from a nervous stomach and have difficulty eating before races, try a liquid meal such as a fruit smoothie or a meal-replacement drink. Your pre-running meal should be low in fat, low in fiber, and high in carbohydrates. And remember to show up to training well hydrated. Drink 2 cups (500 milliliters) of fluid 2 hours before.

  How much should I eat?

  Sport dietitian Dallas Parsons says pre-workout food choices vary widely among runners. The best advice is to experiment during training. This will help you find a pre-race meal that works for you. If you are racing out of town, be sure to plan your pre-race meal. Ask yourself: what will I eat, when will I eat it, and where will I get it?

  Use the guidelines in table 10 to start.

  Table 10

  Is it okay to eat sugar before I exercise?

  Some runners are concerned that they may experience a drop in blood sugar levels and energy if they eat carbohydrates in the hour prior to exercise. Research shows that although an increase in plasma insulin following carbohydrate ingestion in the hour prior to exercise can result in temporary low blood sugars during subsequent exercise, there is no convincing evidence that this is always associated with impaired running performance. With that said, individual practice should be based on individual experience.

  If this is a concern, avoid eating simple sugars (for example, candy, gels, sport drinks) 30 to 45 minutes before training. The night before your race, eat a mixed meal that includes carbohydrates, protein, and vegetables. Here are some examples:

  • pasta with tomato-vegetable sauce, shrimp, chicken, or lean ground meat

  • tofu and vegetable stir-fry over rice or noodles

  • bean-and-vegetable soup with salad, bread, and milk

  • grilled fish, steamed vegetables, and brown rice

  If eating 2 or more hours before running, eat a small high-carbohydrate meal that is low in fat and has a minor amount of protein for lasting energy. For example:

  • low-fat yogurt, with low-fat granola with raisins

  • bagel with peanut butter and honey and juice

  • ready-to-eat cold cereal with low-fat, flavored soy milk

  • oatmeal with 1 percent milk and a piece of fruit

  • pita pocket with vegetables and tuna, grapes, and arrowroot cookies

  • chicken breast with rice, steamed vegetables, and fruit yogurt

  Best foods for recovery

  During training or races, your body loses fluids and uses a lot of muscle glycogen. Carbohydrates and water are what your body needs to replenish. If you’re dehydrated and glycogen-depleted, your body cannot recover and perform well during subsequent training. As part of your training, make it a habit to drink at least 2 cups (500 milliliters) of fluids as soon as you can after finishing a run. Ideally, refuel 10 to 15 minutes post-exercise.

  If eating 1 hour before running, drink a liquid meal such as a yogurt-and-fruit smoothie or meal-replacement drink. Sport bars are another alternative, but be sure to choose one that provides at least 30 grams (1 ounce) of carbohydrate and less than 10 grams of protein. Consider the following options:

  • bagel, jam, milk

  • fruit smoothie made with milk, yogurt, juice, and fruit

  • toast with peanut butter and honey, sport drink

  • pasta with tomato sauce, milk

  If running first thing in the morning, have a glass of sport drink, diluted fruit juice, or water, and an energy gel. These options will provide approximately 75 to 100 calories and should prevent light-headedness or low blood sugars during a 30- to 45-minute run, provided a good meal was eaten the night before.

  Fuel for your long
runs

  Sport dietitian Dallas Parsons says:

  • If you are well fueled before you run and training for only 1 hour, water will suffice in most cases.

  • If the weather is very hot, or if you are unaccustomed to warm temperatures, a sport drink is a good idea even for shorter runs, because it encourages drinking and replenishment of fluids, carbohydrates, and sodium. For training runs lasting longer than 2 hours, take along a carbohydrate source to keep up your energy supply to your working muscles and brain. Start with 30 grams of carbohydrate per hour after the first hour. Some people need more than this and may go up to 60 grams per hour.

  • Another general guideline for fueling while running is 1 gram of carbohydrate per kilogram of body weight per hour after the first hour. Energy gels and sport drinks are among the most popular supplements used during long runs. Some runners can tolerate solids, such as bites of a sport energy bar or Fig Newton cookies.

  By race day you should have a plan that combines the best fluid and fuel replacement to support your needs and preferences. On the day, you may experience unexpected conditions such as wind, hot weather, or cramping; you should be ready and able to adjust your nutrition plan as needed.

  Be sure to replenish your fluids after running. Weight lost during running is due to loss of water. For every pound (half kilogram) of weight lost during a workout, drink 3 cups (750 milliliters) of fluid.

  After interval work or long training runs, which put more stress on your muscles and energy stores, it’s important to rehydrate and have a recovery snack within 30 minutes of completing exercise. Blood flow to the muscles is greater then, and muscle cells are more insulin-sensitive. At this time the body is able to maximize glycogen replenishment and muscle repair.

  Read the labels on your sport products

  You may be wondering whether you need to use special sport products such as protein powders, meal-replacement drinks, and energy bars. Aside from being expensive, these products can quickly add excess calories to your day. Read the labels carefully to check their energy, carbohydrate, protein, and fat content, and always consume with plenty of water. If choosing a bar, look for one with a three- or four-to-one ratio of carb to protein and less than 3 grams of fat per 100 calories.