Optimize your performance by proper fueling.

mance. Adopting specific nutritional strategies before, during, and after

training and competition helps to optimize performance and promote health. The proper amount of food, the composition of the meal, and the timing of food intake also enable runners to train and perform more effectively and reduce the risk of illness and injury (Burke et al. 2007; International Olympic Committee 2010; Rodriguez et al. 2009; Burke et al. 2011).

\ utrition has a significant influence on marathon and ultramarathon perfoEnergy intake

Energy requirements depend on arunner’s periodized training load and competition program and vary from day to day and with the competition schedule. Runners should consume adequate energy and carbohydrate during training to maintain a desirable training intensity and thus maximize training adaptations (International Olympic Committee 2010; Rodriguez et al. 2009).

To meet energy demands, runners may need to eat meals and snacks continually throughout the day. They should fine-tune their fueling strategies based on running intensity and duration and environmental conditions. Testing specific foods and fluids before, during, and after training sessions also allows runners to determine effective fueling strategies for competition (Burke et al. 2007; International Olympic Committee 2010; Rodriguez et al. 2009; Burke et al. 2011).

Failure to match energy intake to energy expenditure during training impairs endurance running performance because of muscle and liver glycogen depletion. Compared with male runners, female runners are more likely to consume insufficient energy (International Olympic Committee 2010; Rodriguez et al. 2009).

Energy requirements for competition are often higher than during training, especially for ultra-endurance events (such as 50- and 100-mile runs) and multipleday events. In ultra-endurance running events lasting about 24 hours, it is not necessary or practical to meet total energy expenditure (O’Connor and Cox 2002).

O’Conner and Cox noted that an athlete who ran around Australia lost only about 5 kilograms after averaging approximately 47 miles per day for 191 days (O’Connor and Cox 2002). His estimated energy expenditure was 6,321 kilocalories per day (kcal/day) (Hill and Davies 2001) and estimated energy intake was 6,000 kcal/day (O’Connor and Cox 2002). A typical day’s intake provided about 100 grams of protein, more than 1,000 grams of carbohydrate, and 120 grams of fat (O’Connor and Cox 2002).

Fudge et al. (2006) reported that elite Kenyan endurance runners consumed 3,152 kcal and expended 3,478 kcal during periods of intense training. Burke et al. (1991) reported that elite Australian male marathon runners who ran 91.6 miles per week consumed 3,570 kcal per day. Motonaga et al. (2006) reported that male Japanese marathon runners who ran 405 miles per month consumed 3,784 calories per day.

Eden and Abernathy (1994) reported that a male ultradistance runner in the Sydney to Melbourne race (628 miles in 8.5 days) consumed 5,952 kcal/day.

Glace et al. (2002a) found that male ultrarunners incurred an energy deficit of 7,513 kcal in 24.3 hours during a 100-mile run. Their estimated energy intake was 6,047 kcal and estimated energy expenditure was 13,560 kcal. In another study, Glace et al. (2002b) found that male and female ultrarunners incurred an energy deficit of 2,516 kcal in 26.2 hours during a 100-mile run. Their estimated energy intake was 7,022 kcal and estimated energy expenditure was 9,538 kcal.

Moran et al. (2011) reported that a female ultrarunner consumed 2,592 kcal in 12 hours, 49 minutes during a 62-mile (100K) run. Fallon et al. (1998) reported that male ultrarunners consumed 1,011 kcal in 10 hours, 48 minutes during a 62-mile (100K) run.

Practical suggestions to increase energy and carbohydrate intake are provided in later sections of this article.

Carbohydrate

Adequate carbohydrate stores (muscle and liver glycogen and blood glucose) are critical for optimum endurance performance. Fatigue during prolonged running is often associated with muscle glycogen depletion and/or hypoglycemia. Thus, nutritional strategies that optimize carbohydrate availability before, during, and after exercise are recommended to improve endurance performance (Burke et al. 2011).

Nutrient-dense carbohydrate foods and fluids should be emphasized during training because they contain other nutrients such as vitamins and minerals that

are important for the overall diet as well as recovery from exercise (Rodriguez et al. 2009.).

The runner’s carbohydrate and energy intake should be adjusted or “periodized” to meet the requirements of the particular training cycle or phase for his or her sport. Excessive energy intake during light training can cause an increase in body fat, which may have a negative effect on performance. Conversely, inadequate carbohydrate and energy intake during heavy training can cause loss of lean tissue, depleted carbohydrate stores, and impaired performance. Ideally, the athlete should lose excess body fat in the off-season or early in the training cycle (International Olympic Committee 2010; Rodriguez et al. 2009).

Runners engaged in moderate-intensity training programs for 60 minutes per day should consume 5 to 7 grams per kilogram of body weight per day (g/kg/d) of carbohydrate/kg per day. During moderate- to high-intensity endurance exercise for one to three hours, runners should consume 6 to 10 g/kg/d of carbohydrate/ kg/day. Runners participating in moderate- to high-intensity endurance exercise for four to five hours per day should consume 8 to 12 g/kg/d of carbohydrate/kg per day. These are general recommendations and should be adjusted with consideration of the athlete’s total energy needs, specific training needs, and feedback from training performance. Carbohydrate intake should be spread over the day to promote fuel availability for key training sessions—before, during, or after exercise in the training cycle (Burke et al. 2011).

Fudge et al. (2006) reported that elite Kenyan endurance runners consumed 9 g of carbohydrate/kg/day. Burke et al. (1991) reported that elite Australian male marathon runners who ran 91.6 miles per week consumed 8 g of carbohydrate/ kg/day. Eden and Abernathy (1994) reported that a male ultradistance runner in the Sydney to Melbourne race consumed 17 g of carbohydrate/kg/day.

Training for endurance events involves hours of prolonged exercise that may include multiple daily training sessions. The stress of such rigorous training can decrease appetite, resulting in reduced consumption of energy and carbohydrate. Runners who have extremely high carbohydrate requirements and suppressed appetites due to heavy endurance training or competition should include compact, low-fiber forms of carbohydrate, such as pasta, white rice, sport bars and gels, baked goods (cake, tarts, biscuits), and sugar-rich foods (such as candy). Carbohydrate-rich fluids such as sport drinks, juices, high-carbohydrate liquid supplements, low-fat chocolate milk, soft drinks, commercial liquid meals, milkshakes, yogurt drinks, and fruit smoothies may also be appealing to runners who are very tired and dehydrated (O’Connor and Cox 2002).

O’Conner and Cox (2002) noted that the athlete who completed the run around Australia consumed pancakes, toast, porridge, sandwiches with protein fillings, rice/pasta, “instant” noodle meals, muffins, cereal bars, fruit, pastries, canned vegetables, cheese, tofu, eggs, nuts, fish, and pasta in addition to carbohydraterich fluids. A large range of sport foods (such as liquid meals, sport bars, sport gels, high-carbohydrate supplements, and sport drinks) were used because they are easy to consume, portable, and easy to store.

Protein

During low- to moderate-intensity endurance activity, protein intake of 1.2 g/ kg/d is sufficient when energy and carbohydrate intake are adequate (Tarnopolsky 2004). Elite endurance athletes may require 1.6 g/kg/d, twice the recommended dietary allowance of 0.8 g of protein/kg/day for sedentary people (Tarnopolsky 2004). Friedman and Lemon (1989) found that well-trained endurance runners required 1.5 g/kg/d to maintain nitrogen balance.

The runner’s sex may affect protein metabolism. During endurance exercise, women oxidize more lipids and less carbohydrate and protein compared with equally trained and nourished men. Female runners may have a 10 percent to 20 percent lower protein requirement compared with male runners. This seems to be due to sex-based hormonal responses that promote fat metabolism in women and carbohydrate-protein metabolism in men. Runners can meet their higher protein requirements by consuming a mixed diet that provides adequate energy and 15 percent of energy from protein (Tarnopolsky 2006).

Fudge et al. (2006) reported that elite Kenyan endurance runners consumed 2.1 g of protein/kg/day. Burke et al. (1991) reported that elite Australian male marathon runners who ran 91.6 miles per week consumed 2 g of protein/kg/day. Eden and Abernathy (1994) reported that a male ultradistance runner in the Sydney to Melbourne race consumed 2.9 g of protein/kg/day.

A low-energy and/or low-carbohydrate intake will increase amino-acid oxidation and total protein requirements. Although most runners get sufficient protein, those with low-energy and/or reduced-carbohydrate intakes may require nutrition counseling to optimize dietary protein intake (Glace 2002b).

The Food and Nutrition Board of the Institute of Medicine established an Acceptable Macronutrient Distribution Range (AMDR) for fat at 20 percent to 35 percent of total energy intake (Institute of Medicine 2005). Runners should consume at least 1 g/kg/d.

Fudge et al. (2006) reported that elite Kenyan endurance runners consumed 1 g of fat/kg/day—17 percent of energy intake. Burke et al. (1991) reported that elite Australian male marathon runners who ran 91.6 miles per week consumed 2 g of fat/kg/day—32 percent of energy intake. Eden and Abernathy (1994) reported that a male ultradistance runner in the Sydney to Melbourne race consumed 3.2 g of protein/kg/day—27 percent of energy intake.

Micronutrients

Runners who consume adequate total energy usually meet or exceed population reference values such as the Dietary Reference Intakes (DRIs) for vitamins and minerals. Consuming a nutrient-dense diet containing fruits, vegetables, whole grains, legumes, lean meat, and dairy foods during training also helps to ensure adequate micronutrient intake (Fogelholm 2006).

Runners who regularly restrict energy intake or eat a limited variety of foods may be at risk for suboptimal micronutrient intakes. Some endurance and ultraendurance athletes may have increased requirements due to excessive losses in sweat and/or urine (Fogelholm 2006).

Supplementation may be necessary when intake is inadequate. However, runners should not exceed the Tolerable Upper Intake Level (UL) for any nutrient to prevent possible adverse effects on health and performance. Supplementation with single micronutrients is not recommended (Fogelholm 2006) unless there is a medical necessity (such as iron to treat iron-deficiency anemia).

The dietary antioxidant vitamins C and E play an important role in protecting cell membranes from oxidative damage. Although endurance exercise is associated with increased oxidative stress, it also increases the body’s enzymatic and nonenzymatic antioxidant defenses as an adaptation to training (Watson 2006). In fact, there may be negative effects from the routine consumption of antioxidant supplements during endurance training. Several studies have found that suppression of free-radical generation during exercise can attenuate some of the signals for endogenous adaptation to endurance training (Gomez-Cabrera et al. 2008; Ristow et al. 2009). Until research suggests otherwise, it is prudent to recommend that runners consume an antioxidant-rich diet, rather than supplements, to protect against oxidative damage (Watson 2006; Gomez-Cabrera et al. 2008; Ristow et al. 2009).

Endurance training can increase iron requirements (due to increases in hemoglobin, myoglobin, and iron-containing proteins involved in aerobic metabolism) and iron losses (through sweating, gastrointestinal bleeding, and mechanical trauma such as foot-strike hemolysis). The debilitating effects of iron-deficiency anemia on endurance performance are well established. Anemia impairs erythropoiesis (red blood cell formation), thereby limiting oxygen delivery to the muscles, VO,max, and endurance performance (Rodriguez et al. 2009; Deakin 2006; Schumacher et al. 2002).

The effects of iron depletion (stage 1 iron deficiency) on endurance performance are less clear. At the very least, iron depletion can progress to iron-deficiency anemia if untreated. Runners, especially women, are at risk for depleting their iron stores. Although depleted iron stores should not affect VO,max because hemoglobin levels are not compromised, inadequate tissue iron stores may reduce

oxidative metabolism in the muscle and impair endurance performance (Ristow et al. 2009; Deakin 2006).

Research using a new indicator for tissue iron deficiency known as serumtransferrin receptor suggests that even stage 1 iron deficiency (depleted iron stores) may compromise aerobic and endurance capacity (Hinton et al. 2000). Hinton et al. (2000) found that iron supplementation in iron-depleted nonanemic women significantly improved endurance capacity and serum-ferritin and serum-transferrin receptor concentrations, but the supplementation did not affect hemoglobin concentrations. Further analysis of this data showed that tissue iron deficiency impaired adaptations to endurance training (Brownlie et al. 2002). Subjects with the most tissue iron depletion also showed the greatest improvement in endurance capacity after supplementation (Brownlie et al. 2004).

Runners at risk for iron deficiency should have routine checks of their iron status. A low plasma-ferritin level (< 20 micrograms per deciliter) may indicate tissue iron deficiency, which can impair endurance. The runner’s iron stores can be increased through diet and/or iron supplementation to prevent the negative consequences of iron deficiency (Deakin 2006).

Inadequate dietary calcium and vitamin D increase the risk of low bonemineral density and stress fractures. Female runners who have low energy intakes, eliminate dairy products, or have menstrual dysfunction are at high risk for low bone-mineral density. Supplementation with calcium and vitamin D should be determined after nutrition assessment (Rodriguez et al. 2009).

There is limited data on the micronutrient intake of endurance athletes. Singh et al. (1993) reported that ultramarathoners had adequate prerace intakes of vitamins and minerals from both food and supplements. The biochemical indexes of the ultramarathoners’ vitamin and mineral status were also normal. O’Connor and Cox (2002) reported that the male ultradistance runner who completed the run around Australia consumed two to three times the RDA for micronutrients. Eden and Abernathy (1994) found that all of the micronutrients except riboflavin were met in the diet of a male ultradistance runner competing in the Australian Sydney to Melbourne foot race.

Water and sodium

Drinking during endurance exercise is necessary to prevent the detrimental effects of excessive dehydration (greater than 2 percent body weight loss) and electrolyte loss on exercise performance and health. Dehydration increases physiologic stress as measured by core temperature, heart rate, and perceived exertion, and these effects are accentuated during exercise in warm to hot weather. The greater the body-water shortage, the greater the physiologic strain and the greater the impairment of endurance performance (Sawka et al. 2007).

It is not possible to propose a one-size-fits-all fluid and electrolyte replacement schedule because of the multiple factors that influence sweating rate and sweat electrolyte concentration. Runners who have high sweat rates and a high sweatsodium concentration (“salty sweat”) can sustain substantial losses of sodium (Montain et al. 2006).

Symptomatic exercise-associated hyponatremia (plasma sodium concentration <135 millimoles per liter) can occur in events lasting more than four hours. Contributing factors to exercise-associated hyponatremia include drinking an amount of fluid that exceeds sweat and urinary water losses and excessive loss of total-body sodium (Sawka et al. 2007).

In events that last less than four hours, hyponatremia is primarily caused by overdrinking before, during, and after the event. During a marathon, symptomatic hyponatremia is more likely to occur in smaller and less lean individuals who tun slowly, sweat less, and drink excessively before, during, and after the race (Montain et al. 2006; Hew et al. 2003).

During prolonged ultra-endurance exercise such as a 100-mile run, total sodium losses can induce symptomatic hyponatremia if the runner is drinking too little or too much fluid (Brownlie et al. 2002). High sweat rates and a high sweat-sodium concentration confer a greater risk of developing hyponatremia because less fluid intake is required to produce dangerously low blood-sodium levels (Montain et al. 2006).

Runners can experience health problems from either dehydration or overdrinking. Dehydration is more common and can impair exercise performance and contribute to serious heat illness. However, symptomatic hyponatremia is more dangerous and can cause grave illness or death. Because of the considerable variability among individuals in sweat rates and sweat-electrolyte content, athletes should customize their fluid-replacement plans (Sawka et al. 2007).

Before the run

Muscle-glycogen supercompensation

Carbohydrate loading can improve performance in events exceeding 90 minutes. The regimen can be viewed as an extended period of “fueling up” to prepare for competition.

Several studies have suggested that runners can carbohydrate load in as little as one day (Bussau et al. 2002; Fairchild et al. 2002). A high-carbohydrate diet of 10 g/kg/day significantly increased muscle glycogen from preloading levels of about 90 millimoles per kilogram to about 180 millimoles per kilogram after one day (Bussau et al. 2002). A high-carbohydrate intake of 10.3 g/kg following a three-minute bout of high-intensity exercise enabled athletes to increase muscleglycogen levels from preloading levels of about 109 mmol/kg to 198 mmol/kg in 24 hours (Fairchild et al. 2002).

These studies suggest that muscle-glycogen supercompensation is probably achieved within 36 to 48 hours of the last exercise session as long as the runner rests and consumes adequate carbohydrate. For most runners, a carbohydrateloading regimen will involve two days of a high-carbohydrate intake (10 to 12 g of carbohydrate/kg) along with tapered training (Burke et al. 2011).

Some runners may have difficulty tolerating carbohydrate-rich foods that are high in fiber. To avoid gastrointestinal distress, runners may benefit from consuming low-fiber foods such as pasta, white rice, pancakes, cereal and fruit bars, sports bars and gels, yogurt, baked goods, and low-fat or fat-free sweets (such as hard candy). Most runners need to eat frequently throughout the day to consume adequate carbohydrate and energy. Carbohydrate-rich fluids such as sports drinks, 1 percent fat chocolate milk, liquid meals, high-carbohydrate supplements, yogurt drinks, and fruit smoothies help to augment carbohydrate and energy intake.

As with other nutritional strategies, runners should test their carbohydrateloading regimen during a prolonged workout or a low-priority race.

Carbohydrate

Consuming carbohydrate prior to prolonged runs can help performance by maintaining blood-glucose levels. The runner should consume 1.0 to 4.0 grams of carbohydrate per kilogram of body weight, one to four hours before exercise. To avoid potential gastrointestinal distress when blood is diverted from the gut to the exercising muscles, the carbohydrate and energy content of the meal should be reduced the closer to exercise the meal is consumed. For example, a carbohydrate feeding of 1 g/kg is appropriate one hour before exercise, whereas 4.0 g/kg can be consumed four hours before exercise (Burke et al. 2011; Sherman et al. 1989; Sherman et al. 1991).

Foods that are low in fat, low-moderate in protein, and low in fiber are recommended as they are less likely to cause gastrointestinal upset. Liquid meals can often be consumed closer to running than regular meals can due to their shorter gastric-emptying time. Including some low-glycemic index foods may provide a more sustained source of fuel for situations where carbohydrate cannot be consumed during the run. Runners should choose palatable, familiar and welltolerated foods (Burke et al. 2011).

Fluids

Runners should also begin exercise with normal hydration and plasma-electrolyte levels. Prior to exercise, the runner should drink approximately 5 to 7 mL of fluid per kg of body weight about four hours before exercise; 7 mL/kg is equivalent to approximately 1 ounce for every 10 pounds of body weight. Drinking several

hours before exercise allows adequate time for the urine output to return toward normal (Sawka et al. 2007).

Runners should experiment with different preexercise foods and fluids during training. The type of event, personal experiences, and food preferences will determine the timing of intake and the amount and type of food and fluids consumed (Burke et al. 2011). Before competition, runners should choose familiar, well-tolerated, and palatable foods and fluids (Burke et al. 2011).

During the run Carbohydrate

Consuming carbohydrate during runs lasting at least one hour can delay the onset of fatigue and improve endurance capacity by maintaining blood glucose levels and carbohydrate oxidation in the latter stages of exercise (Burke et al. 2011; Coyle et al. 1983; Coyle et al. 1986).

The recommendations for carbohydrate intake during exercise can be absolute (grams per hour) and not based on body weight. Consuming carbohydrate is neither practical nor necessary during runs lasting less than 45 minutes (Burke et al. 2011). Small amounts of carbohydrate from sport drinks or foods may enhance performance during sustained high-intensity endurance exercise lasting 45 to 75 minutes (Burke et al. 2011). Runners should consume 30 to 60 grams of carbohydrate per hour from carbohydrate-rich fluids or foods during runs lasting one to 2.5 hours (Burke et al. 2011).

As the duration of the event increases, so does the amount of carbohydrate required to enhance performance. During training runs and events lasting 2.5 to 3 hours and longer, athletes should consume up to 80 to 90 g carbohydrate per hour (Burke et al. 2011). Recent research suggests a dose-response relationship between carbohydrate intake and performance during prolonged endurance exercise—higher intakes of carbohydrate are associated with improved performance (Burke et al. 2011; Smith et al. 2010; Pfeiffer et al. 2012).

Carbohydrate-rich fluids, gels, and foods should contain several carbohydrate sources (such as glucose/fructose mixtures) that use different intestinal transporters to maximize carbohydrate absorption from the gut and minimize gastrointestinal distress (Burke et al. 2011; Jeukendrup 2010). Liquid and solid carbohydrate sources are equally effective in increasing blood glucose and improving performance (Pfeiffer et al. 2010a; Pfeiffer et al. 2010b).

Consuming carbohydrate in workouts enables the athlete to maintain a desirable training pace (and therefore maximize training adaptations) as well as practice fueling strategies for competition. Athletes should individually determine a refueling plan that meets their nutritional goals (including hydration) and minimizes gastrointestinal distress (Burke et al. 2011). High-fiber foods should be limited

during competition to avoid gut distress such as abdominal bloating, cramping, and diarrhea.

O’Conner and Cox (2002) noted that the runner who completed the run around Australia consumed sport drinks, fruit juice, soft drinks, high-carbohydrate supplements, milkshakes, and liquid meals during the run itself. Eden and Abernathy (1994) reported that a male ultradistance runner in the Sydney to Melbourne race consumed 39 grams of carbohydrate per hour. The runner utilized a combination of high-carbohydrate solid foods (pasta with meat sauce, rice, bread, biscuits, cheese, muffin with egg, and cheese and fruit), vegetable soup, fruit juice, and a sport drink during running to meet his energy requirements. The foods eaten during the race were based on what the runner had enjoyed eating during training and what he could tolerate while competing.

Glace et al. (2002a) reported that male ultrarunners consumed 44 grams of carbohydrate per hour during a 100-mile run. In another study, Glace et al. (2002b) found that male and female ultrarunners consumed 54 grams of carbohydrate per hour during a 100-mile run. Moran et al. (2011) reported that a female ultrarunner consumed 44 grams of carbohydrate per hour during a 62-mile (100K) run. Fallon et al. (1998) reported that male ultrarunners consumed 43 grams of carbohydrate per hour during a 62-mile (100K) run.

Flavor fatigue

It is essential to have a variety of carbohydrate-rich foods and fluids available during ultra-endurance and multiday events to prevent “flavor fatigue” and an associated decrease in energy intake. Alternating between sweet choices (such as gels, sodas, candy) and savory/salty choices (such as vegetable soup, pretzels, baked chips) helps to maintain the runner’s desire to eat. Consuming solid food with small amounts of protein and fat (such as a turkey, cheese, or peanut butter sandwich) also helps provide satiety and variety (O’Connor and Cox 2002; Moran et al. 2011).

Fluids and sodium

Runners should determine their hourly sweat rate and drink only enough to closely match fluid loss from sweating. The runner should drink sufficient fluid to limit weight loss to 2 percent of initial body weight (Sawka 2007).

During prolonged endurance exercise, a loss of up to 2 percent of body weight is likely to occur from factors unrelated to sweat losses (substrate oxidation) and is acceptable (Jeukendrup 2011). A weight loss of up to 3 percent may be tolerable and not impair performance in cool weather (Jeukendrup 2011). Glace et al. (2002a) estimated that body-fat loss (according to skinfold measurements) accounted for about 1.13 kilograms of the 1.6 kilograms lost (2 percent of body weight) during a 100-mile run.

In a second study, Glace et al. (2002b) found that high fluid intakes during a 100-mile run were associated with decreased serum-sodium levels and increased tisk of mental-status change, suggesting possible fluid overload.

To prevent hyponatremia, runners should avoid overconsumption of fluids and associated weight gain (Sawka et al. 2007). Consuming a sodium-containing sport drink helps to maintain plasma-sodium levels and may reduce the risk of hyponatremia during prolonged exercise (Vrijens and Rehrer 1999; Twerenbold et al. 2003).

Runners participating in events lasting longer than three hours should be particularly meticulous about establishing their fluid-replacement schedule. As the exercise duration increases, the cumulative effects of slight disparities between fluid intake and loss can cause extreme dehydration or hyponatremia (Sawka et al. 2007).

During training, runners should experiment with different fluid-replacement drinks and adjust their drinking strategies based on the workout intensity, duration, and environmental conditions. Drinking appropriately in workouts enables the runner to maintain a desirable training pace (and maximize training adaptations), protects against heat illness, and allows the athlete to practice proper drinking strategies for competition (Sawka et al. 2007).

Pace and fueling

When the runner’s gut blood flow is low (as in a fast-paced marathon), the runner should emphasize carbohydrate-rich fluids (sport drinks, liquid meals, highcarbohydrate liquid supplements, fruit juices, and carbohydrate gels) to promote rapid gastric emptying and intestinal absorption. When the runner’s gut blood flow is moderate (as in the downhill section of ultraruns), the runner may be able to consume easily digested carbohydrate-rich foods such as sport bars, fruit, and grain products (fig bars, bagels, graham crackers) in addition to liquid foods and fluids (Laursen and Rhodes 1999).

Fueling plan

The runner should develop and refine a fueling and hydration plan weeks and even months ahead of the priority race by experimenting in workouts and in lowerpriority races. The runner should test this fueling plan while exercising at race pace and in environmental conditions that simulate the race conditions. Runners should not consume untested foods or fluids during the race because the result may be severe indigestion and poor performance.

Runners should consume liquid or solid fuel before feeling hungry or tired, usually within the first hour of exercise. Consuming small amounts at frequent intervals (every 15 to 20 minutes) helps prevent gastrointestinal upset, maintains blood-glucose levels, and promotes hydration. The runner’s foods and fluids

should be easily digestible, familiar (tested in training), and enjoyable (to encourage eating and drinking) (O’Connor and Cox 2002; Eden and Abernathy 1994).

After the run

Restoring muscle and liver glycogen stores, replacing fluid and electrolyte losses, and promoting muscle repair are important for recovery after strenuous endurance training and multiday events. Utilizing effective refueling strategies following daily training sessions helps to optimize recovery and promote the desired adaptations to training.

Carbohydrate

When there is less than eight hours between workouts or competitions that deplete muscle-glycogen stores, the runner should start consuming carbohydrate immediately after the first exercise session to maximize the effective recovery time between sessions (Burke et al. 2011; Ivy and Katz et al. 1988; Ivy and Lee et al. 1988). The runner should consume carbohydrate at a rate of 1 to 1.2 g/kg/h for the first four hours after glycogen-depleting exercise (Burke et al. 2011). Consuming small amounts of carbohydrate frequently (every 15 to 30 minutes) further enhances muscle glycogen synthesis (Burke et al. 2011). During longer

periods of recovery (24 hours), it does not matter how carbohydrate intake is spaced throughout the day as long as the runner consumes adequate carbohydrate and energy (Burke et al. 2011). Liquid forms of carbohydrate may be desirable when runners have decreased appetites due to fatigue and/or dehydration.

Protein

The runner’s initial recovery snack or meal should include 15 to 25 grams of high-quality protein in addition to carbohydrate (Burke et al. 2011). Consuming protein with recovery snacks and meals helps to increase net muscle-protein balance, promotes muscle-tissue repair, and enhances adaptations involving synthesis of new proteins (Laursen and Rhodes 1999). A dose of 20 to 25 grams of protein can be obtained by consuming about 24 ounces (2 1/2 cups) of skim milk, or three large eggs, or 3 ounces of lean red meat (Laursen and Rhodes 1999). Adding a small amount of protein (about 0.3 g/kg/h) to a suboptimal carbohydrate intake (less than 1 g/kg/h) also accelerates muscle-glycogen restoration (Betts and Williams 2010). Recovery meals and snacks contribute toward the runner’s daily protein and carbohydrate requirements.

The foods consumed during recovery should also contribute to the athlete’s overall nutrient intake. Nutritious carbohydrate-rich foods and lean sources of protein and dairy also contain vitamins and minerals that are essential for health and performance. These micronutrients are important for postexercise recovery processes. Runners should avoid consuming large amounts of foods high in fat or protein when total energy requirements or gastrointestinal distress limits food intake during recovery. These foods can displace carbohydrate-rich foods and reduce muscle-glycogen storage.

Fluids and sodium

Ideally, the runner should fully restore fluid and electrolyte losses between exercise sessions (Sawka et al. 2007). Consuming sodium during recovery promotes fluid retention and stimulates thirst (Nose et al. 1988). Sodium losses are harder to determine than water losses because athletes have vastly different rates of sweat-electrolyte losses (Sawka et al. 2007). Although drinks containing sodium (such as sport drinks) may be beneficial, many foods can supply the needed electrolytes (Sawka et al. 2007). Extra salt can be added to meals and recovery fluids when sweat sodium losses are high; one-half teaspoon (2.5 grams) of salt supplies 1,000 milligrams of sodium.

Runners should drink 24 ounces of fluid for each pound lost to achieve rapid and total recovery from dehydration (Shirreffs and Maughan 1998). The additional volume (150 percent of sweat losses) is required to compensate for the increased urine production that goes along with the rapid intake of large volumes of fluid (Sawka et al. 2007; Shirreffs and Maughan 1998).

Ultra-endurance and multiday events

The importance of proper fueling and hydration during ultra-endurance and multiday events cannot be overemphasized. The runner’s fueling and fluid-replacement strategies can mean the difference between completing the event or dropping out of the race (O’Connor and Cox 2002).

During the event, the runner’s primary nutritional requirements are water, carbohydrate, and sodium (O’Connor and Cox 2003; Coleman 2012). Runners should limit foods that are high in fat, protein, and fiber during exercise to decrease the risk of gastrointestinal distress. The following pointers are also helpful:

¢ The food plan should be built around the athlete’s food preferences and include a variety of foods (savory/salty and sweet) rather than a restricted assortment (O’Connor and Cox 2002; Coleman 2012).

¢ Food and fluid intake should be closely monitored during multiday events. The crew should be prepared to enforce an eating and drinking schedule. If necessary, separate timers can be set for both liquid and solid feedings (Coleman 2012).

¢ Food records and body weight should be assessed daily during multiple-day events. By tracking the runner’s food and fluid intake and body weight, the crew can take immediate corrective action, without overfeeding or causing GI distress, if the runner starts to fall behind on fluid or energy intake (Coleman 2012).

¢ Solid food should be easy to handle, chew, and digest. Beverages should promote rapid absorption of fluids and nutrients. Concentrated nutrition such as high-carbohydrate supplements or liquid meals may be offered immediately before scheduled rest (Coleman 2012).

References

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Brownlie, T., V. Utermohlen, P. S. Hinton, and J. D. Haas. 2004. Tissue iron deficiency without anemia impairs adaptation in endurance capacity after aerobic training in previously untrained women. The American Journal of Clinical Nutrition 79(3):437-443.

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