A fund-raising project benefiting AIDS Project Los Angeles, the program began on May 1 and culminates with the Marine Corps Marathon on Oct. 24 in Washington, D.C. Beginning in Arlington, near the Potomac River, the Marine Corps Marathon will conclude 26.2 miles later at the Marine Corps Memorial.
As with life in general, the key ingredients for marathon training revolve around the big five daily priorities: developing good nutrition habits and making aware food choices, maintaining routine physical activity, getting adequate sleep and rest, building and nurturing one's self-esteem, and loving oneself unconditionally.
Sports nutrition is an integral factor in training for a marathon or any endurance exercise. The basic goals of nutrition include: 1) to provide energy, 2) support new tissue growth and repair, and 3) help regulate metabolism.
Energy comes from three macro-nutrients of food: carbohydrate, protein and fat. Fluids are essential to performance.
Carbohydrates, also called sugars, are considered our master fuel. Carbohydrates provide glucose required for energy in our muscles and brain. To meet the high-intensity aerobic and endurance marathon challenge, a diet that contains 60 to 70 percent of calories coming from carbohydrate, at least 6 g carbohydrate per kilogram (1 kilogram (kg) = 2.2 pounds of body weight) is recommended. The typical American diet is low in carbohydrates at 45 percent total calories or 4 to 5 g per kilogram. To find out how much carbohydrate is in what you usually eat, pick up a book on the nutritive values of foods and pay special attention to reading nutrition labels.
In general, sources rich in carbohydrates include grains, legumes, starchy vegetables and fruits: oats, barley, rice, wheat, beans, peas, soy, corn, potatoes, winter squash, breads, cereals, pasta and all fruits except avocado. Don't be fooled into thinking that you have the green light to eat unlimited amounts of sweets like cookies, cakes, candy and soft drinks. You still need to be cautious.
Sweets commonly don't contain vital vitamins, minerals, phytochemicals and fiber, and eating them may be robbing you of the opportunity to eat more nutritious foods and getting those important nutrients. In addition, many of these items actually contain more fat in them than you probably thought or want to consume.
Compared to grains and fruits, vegetables have fewer carbohydrates. Remember, eat your vegetables! They have a great variety of vitamins, minerals and phytochemicals that you can't get elsewhere.
Protein is necessary for growth and repair. A complete protein source provides all the essential amino acids. Sources of complete protein are dairy, meat and fish. Examples of incomplete protein sources are beans, grains, seeds and nuts.
Vegetarians who seek to fulfill their protein requirement by eating beans and grains should be reminded that the combination does not have to be eaten at the same meal, but they do have to be eaten on the same day.
A protein intake of 1.2-1.4 g/kg of body weight, or 12-15 percent of total calories from protein is recommended. More protein is not necessary since the average non-vegetarian American diet already provides adequate protein and routine protein supplements are discouraged.
For people living with HIV infection, protein recommendations can be slightly increased to 1.5 g/kg body weight or 16 percent of total calories and may range as high as 120 to 140 g protein per day.
Fat provides energy during long-endurance events such as a marathon. The recommendation for fat intake is 20 to 30 percent of total calories from fat. Fat sources can be visible such as the added oils, butter, margarine, fat under the skin of chickens and turkey and the excess and marbling of red meats. Fat sources can also be invisible and hidden such as those found in baked goods like cookies, pies and cakes, in red meats, cheeses, restaurant food preparation, and seeds and nuts and their butters.
Fluid is integral in maintaining body temperature control, energy production, elimination of waste and avoiding dehydration. Water is an essential nutrient and at least 64-96 oz (8 to 12 cups) of decaffeinated fluid per day is recommended. In general we recommend 80 to 96 oz. (10 to 12 cups) for men and 72 to 88 oz. (9 to 11 cups) of safe water for persons living with HIV.
Choose safe bottled water. We recommend known brands where the label clearly states that the water has been processed by distillation or reverse osmosis. These waters can have added minerals and may be called drinking water, but be cautious and check that the drinking water label clearly states it has gone through these processes.
Electrolytes (sodium, chloride and potassium) are necessary for maintaining hydration, contraction of muscles, and transmission of nerve impulses. Normal amounts of electrolytes are easily supplied in a healthy diet from a variety of foods. Heavy sweat losses and exercising in warm weather, like we have in Southern California, can make sodium losses a problem that lightly salting food can easily correct. Sodium tablets should not be taken.
Variety of food intake is always the key. However, when caloric intake from a good healthy variety of foods is limited, a general vitamin and mineral supplement may be necessary. While some vitamins are involved in the release of energy, remember that vitamins do not provide energy. Calories provide energy.
With increasing miles run and time spent running, carbohydrates become more important than ever. Storage of carbohydrates in the body, called glycogen stores, is limited and becomes lower when exercising more than 90 to 120 minutes. When glycogen stores drop too low, fatigue and exhaustion set in and performance drops or stops all together. To offset this, the emphasis is placed on higher carbohydrate diet and routine rest days to allow muscles to replenish the glycogen stores. Increasing carbohydrates to 8 to 10 g carbohydrate per kilogram body weight is recommended with harder and longer training periods.
Diet and training the week prior to the marathon can be manipulated to increase glycogen storage capacity. Training time and carbohydrate intake changes are called "carbohydrate loading." Remember, training -- using your muscles -- is what is stimulating muscle glycogen building and if you are not training, this won't work.
The increase in carbohydrate stores will cause an increase in water stored, which may cause a feeling of muscle stiffness. This will work its way out in the endurance exercise.
The pre-event diet is high-carbohydrate, low-fat and low fiber. It should be consumed one to four hours before exercising and with 16 to 24 ounces (2 to 3 cups) of fluid. Eight to 16 ounces (1 to 2 cups) of fluid should be drunk 15 minutes before the event.
The experienced marathon runner understands the importance of easy-to-absorb fluid and carbohydrates during the event. It is recommended that during the event to drink every 15 minutes 4 to 8 oz. (1/2 to 1 cup) of fluid and to get in an intake of 30-60 g of carbohydrate (120-240 calories) every hour. Remember to take little bites at a time and be careful, as too many calories at one time may cause gastrointestinal upset.
Drinking and eating by the clock and long before you become aware you are thirsty or hungry is critical. By the time you become aware that you are thirsty or hungry, it is too late.
Fluids are lost during the event and it is helpful to know what you weigh before and after the event. Drinking 16 ounces of fluid that for every pound that is lost during the event is recommended. Within 30 minutes after the event, glycogen stores should be replenished by taking in 1.5 g carbohydrate per kilogram body weight. For example, a 150-pound (68 kg) person, would need 102 g carbohydrates. This could look like 2 cups of a sports drink (28 to 30 g carbs), 1/3 of a powerbar (15 g carbs), a banana (27 g carbs) and a bagel (31 g carbs).
Electrolytes (sodium, chloride and potassium) are lost during energy exertion and must be replenished as well. Sports drinks that contain sodium in addition to plain water should be consumed during the marathon and immediately after to avoid low blood sodium and to aid in recovery.
If you are considering a dietary supplement to assist in running performance, remember that the dietary supplement market is poorly regulated. Quality is not necessarily guaranteed and health claims are not necessarily true. Sadly, it is a "buyer beware" world.
Sport beverages should contain about 60 to 80 calories from carbohydrate per 8 oz. (15 to 20 g or 6 to 8 percent concentration of carbohydrate) for optimal absorption and performance. Choose a sports drink that also contains electrolytes.
Sport gels are semi-solid forms of food that are typically high in simple carbohydrates (28 to 40 g per packet). They are easier to digest than solid foods, and should be followed by 8 to 12 ounces of water to help with absorption. Sticking with the high-carb gels and avoiding sport gels that are high in protein and caffeine is recommended. While small amounts of caffeine may improve endurance performance, potential side effects of caffeine include nausea, muscle tremors, palpitation and headache as well as contributing to dehydration and inadequate rehydration recovery.
The sport bars recommended for runners -- Boulder Bar, Tiger Sport, PowerBar or Clif Bar, for example -- are those that are high in carbohydrate, low in fat, low in fiber and moderate in protein. Sport bars should also be followed by at least 12 to 16 oz. of water and should be eaten in small bites within one hour.
Consumers must critically evaluate the claims of ergogenic aids, which claim to improve performance. Some scientific evidence is available for the effectiveness of caffeine, creatine monohydrate, and phosphates as performance-enhancing supplements, however this can be considered a form of "doping." Carnitine, Co Enzyme Q10, metabolic bars, pyruvate, and glycerol have not been proven to be effective performance enhancing supplements.
Marcy Fenton, M.S., R.D., is the HIV nutrition advocate in the Nutrition & HIV Program at AIDS Project Los Angeles and can be reached at (323) 993-1612 or mfenton@APLA.org. Nellie Duran is an APLA volunteer and a graduate student in nutrition science at California State University at Los Angeles. Both are participating in the National AIDS Marathon Training Program and donations can be submitted in their names. For more information, call the National AIDS Marathon Training Program office at (323) 993-1400.
This article was based in part on a presentation by Tammy Darke, R.D., C.N.S.D., titled "Sports Nutrition for Increased Athletic Performance." Tammy is a registered dietitian at the C.A.R.E. Clinic in Long Beach, where she is part of a model HIV medical team. She is also a member of the Sports, Cardiovascular and Wellness Nutrition Dietetic Practice Group and the HIV/AIDS Dietetic Practice Group, both part of The American Dietetic Association, and locally, a member of Dietitians in AIDS Care. Tammy has competed in more than 30 triathlons, six marathons and ran in the 1999 Boston Marathon in April.