Nutrition and Fuel Systems for Sport

Nutrition and Fuel Systems for Sport

He must rise at five in the morning, run half a mile at the top of his speed up hill, and then walk six miles at a moderate pace, coming in about seven to breakfast, which should consist of beef steak or mutton chop, under-done, with stale bread and old beer.

Captain Robert Barclay Allardice’s nutrition advice to long-distance walkers (c. 1810)

If I asked you to define healthy eating, you would likely give a very acceptable answer: ‘Plenty of fruits and vegetables, whole-grain cereals . . . include lean meats and dairy foods . . . go easy on the cakes and take-aways’. Basically, this is correct, but it is easy to become confused by what we hear from the media and friends and what we read in books and magazines. As a result, we often go against our basic instincts. This chapter will help you think about what foods to eat both for health and to get the best out of your body, as well as the nutrients in these foods.

Good nutrition is quite simple to achieve. Eat lots of minimally processed foods such as vegetables, grains, nuts, fruits, lean meats and reduced-fat dairy foods (except Camembert and premium ice cream because they taste the best with the fat left in!). Figure 1.1 on page 4 shows the Healthy Eating Plate with the major food groups in the proportion needed for good nutrition and to fuel an active body. This Healthy Eating Plate, from the Commonwealth Department of Health and Ageing in Australia, is very similar to the food guidelines of most Western nations and is especially suited to athletes and other active people.

Food Groups

Foods are divided into groups, each of which provides essential nutrients. The underlying science is well established and similar across every reputable health source, although health authorities sometimes differ in how they name the food groups (e.g., fruit and vegetables might be in separate groups or the same group). Table 1.1 lists the minimum serves recommended from each food group for good health.

Fruit, Vegetables and Legumes

This group should make up about a third of what you eat because it plays an essential role in protecting the body from disease now and in the future. This group is the major source of antioxidants and fibre in your diet. These foods also provide appreciable amounts of essential minerals and vitamins. The legumes can be a major protein source for vegetarians (legumes are beans such as kidney beans, lentils and baked beans). This food group is underconsumed by many people in the Western world. Eating more fruit and vegetables can be the single biggest nutritional improvement many people can make. Around the world, ‘Eat more fruit and vegetables’ campaigns encourage people to eat two serves of fruit (about 300 g [10 oz]) and at least 2 cups of vegetables (about 400 g [14 oz]) each day. Australia has the Go for 2&5 campaign (2 serves of fruit and 5 serves of vegetables; www.gofor2and5.com.au), the USA has the 5 A Day campaign (www.cdc.gov/nccdphp/dnpa/5aday/) and the UK promotes five portions a day (www.eatwell.gov.uk/healthydiet/nutritionessentials/fruitandveg/; www.nhs.uk/Livewell/5ADAY/Pages/Whatcounts.aspx).

One serve of fruit
150 g or 5 oz (e.g., 1 medium apple or orange or 2 apricots or 1 cup canned fruit); one serve of vegetables = 1/2 cup cooked vegetables or legumes or 1 cup salad

Bread and Cereals

This group should also comprise around one third of the diet. It includes pasta, rice, bread, breakfast cereals, muesli and porridge. This group is also a major source of fibre for regularity and general bowel health. Breads and cereals provide some antioxidants, especially in the least processed, whole-grain variety. These foods are your best carbohydrate source; they get broken down to glucose, the main fuel source for active muscles, the liver and the brain.

Some people suggest cutting down or cutting out carbohydrate foods to be healthy and lose weight. In reality, if you do so, you are cutting down on fibre and muscle fuel, making you more prone to tiredness and constipation! High-carbohydrate foods are only likely to make you fat if you are inactive or they come with a lot of added fat, such as pastries and cakes. The least processed grain and cereal foods provide more nutrients per serve than biscuits, cookies or pastries.

One serve of breads and cereals
2 slices of bread; 1 bread roll; 1 cup of cooked pasta, rice or porridge; or 40 g (1.4 oz) breakfast cereal

Milk, Yogurt and Cheese

Dairy foods are your main source of calcium and also provide an appreciable amount of riboflavin and protein. I recommend the lower-fat varieties of milk and cheese because they provide less saturated fat and more protein and calcium. Virtually all reduced-fat milks and yogurts have more protein and calcium than the regular versions. Some milks are specifically calcium fortified, allowing you to get up to 400 milligrams of calcium in a 200-millilitre glass. If you don’t fancy dairy foods, then take some calcium-fortified soy drinks as a substitute. (Make sure soy drinks state that they are calcium fortified on the label because there is very little naturally occurring calcium in soy.)

One serve of dairy
1 cup milk; 1 cup calcium-fortified soy drink; 40 g (1.4 oz) cheese; or 200 g (7 oz) yogurt

Lean Meat, Fish, Poultry, Eggs, Nuts and Legumes

This group of foods is very important in providing protein and essential minerals. Lean meat is a very good source of easy-to-absorb iron and zinc. Fish have gained prominence because the omega-3 fat found in cold-water fish has been strongly linked to a reduced risk of heart attacks. Eggs, nuts and legumes are very important protein sources for many vegetarians. Both nuts and legumes provide fibre and antioxidants, so it is no surprise that they appear to lessen the risk of heart disease, some cancers and possibly diabetes. You will often see legumes listed with protein foods and also in the vegetable group because they are a very important source of protein in vegetarian diets, while providing fibre and nutrients common to vegetables.

One serve of meats
100 g (3.5 oz) cooked meat, chicken; 120 g (4.2 oz) cooked fish; 2 eggs; 1/2 cup legumes; or 1/3 cup nuts

Oil and Fat

Oil and unsaturated margarine provide vitamins D and E and help improve the flavour of many foods. Oil is 100 per cent fat, whereas butter and margarine are around 80 per cent fat. ‘Light’ margarine may be as low as 40 per cent fat with some of that fat being replaced by water. Most people need to limit oil and fat because they are high in energy (kilojoules/calories), although athletes can afford a higher fat intake because they are likely to burn it up in training. Note: Technically, calories is often capitalised when referring to kilocalories, but in keeping with common public usage of the term, in this book we will use calories to mean kilocalories, even though it is not capitalised. However, kilojoules are never referred to as joules; hence, we use the term kilojoules for countries that use metric.

One serve of oil and fat
1 tbsp oil, butter, margarine or 1 1/2 tbsp reduced-fat spread

Treats

OK, this is not really a food group, but many people enjoy treats in small amounts during or between meals. Some treats provide essential nutrients. Ice cream provides calcium and protein and is a nutritious dessert with canned fruit. Chocolate provides essential vitamins and minerals, along with antioxidants (in dark chocolate, in particular), but being 30 per cent fat, it cannot be eaten in large amounts. Biscuits, cookies, cakes, pastries, pies and take-aways are often high in saturated fat, salt or both; these should be enjoyed, but greatly limited.

One serve of treats
25 g (0.9 oz) chocolate; 40 g (1.4 oz) cake; 30 g (1 oz) crisps; 1 doughnut; one 375 mL (12.7 oz) can soft drink; 200 mL (7 oz) wine; 400 mL (13.5 oz) regular beer; 12 hot chips or french fries; or 2 cream cookies or biscuits

Water

Yes, water is a nutrient and a most essential one as well. Your body loses fluid each day through exhaled air, urine, sweat and feces. These losses vary depending on the air temperature and how much sweat you lose each day, but a loss of 1,500 to 3,000 millilitres (3 to 6 pints) of water a day is an average range for active people. You can get your fluid needs from water, tea, coffee, fruit juice, cordial, soft drinks, sports drinks and high-water foods such as milk, ice cream, fruits, vegetables and soup. Water requirements are discussed later in the chapter.

Essential Components of Food

Food comprises protein, fat, carbohydrate, fibre, vitamins, minerals and many bioactive compounds such as the antioxidants found mainly in fruits and vegetables. Alcoholic drinks also include alcohol (ethanol), which is technically a nutrient. We will look at each nutrient in turn.

Protein

Protein is composed of long chains of amino acids (see figure 1.2). Amino acids are the building blocks that make up large protein molecules. The digestive process breaks the protein mainly into groups of one, two or three amino acids, which are then absorbed from the intestine and into the blood to be made into body proteins such as haemoglobin, ferritin, antibodies, enzymes, hair and muscle. Some amino acids must come from food (indispensable, or essential, amino acids), whereas the body can make the others (dispensable, or nonessential) even though they still come from food.

Protein has many functions in the body:

Enzymes are forms of protein that enable chemical reactions to take place in the body; they are involved in the digestive breakdown of food via digestive enzymes.Cell membranes, tendons and cartilage are composed of structural protein.Blood has important forms of protein, such as haemoglobin, which transports oxygen around the blood; transferrin is a protein that transports iron around the body; and albumin is a protein that controls water balance in the cells.Antibodies are a specialised form of protein that helps protect us from disease.Muscle strength comes from the contractile proteins actin and myosin, which allow muscles to contract and relax in exercise.Skin, nails and hair are made of strong proteins that can cope with the rigours of daily life.

In Western countries, animal foods provide most of the protein. Foods such as meat, chicken, fish, milk, cheese, yogurt and eggs have protein that provides all of the essential amino acids for life. This is not to discount other valuable sources of protein. About one third of our protein comes from cereal foods (e.g., bread, rice), legumes, fruits and vegetables. Some plant foods will be low in some of the essential amino acids. A combination of plant foods, however, can provide all of the essential amino acids at one meal (complete protein). Some examples are legumes with cereal foods (e.g., beans on toast, lentils with rice) and seeds or nuts with grains (e.g., peanut butter sandwich). In some countries, rice and beans are a major source of complete protein.

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Nancy Clark’s Sports Nutrition Guidebook will help you make the right choices in cafes, convenience stores, drive-throughs, and your own kitchen.

Whether you’re preparing for competition or simply eating for an active lifestyle, let this leading sports nutritionist show you how to get maximum benefit from the foods you choose and the meals you make. You’ll learn what to eat before and during exercise and events, how to refuel for optimal recovery, and how to put into use Clark’s family-friendly recipes and meal plans.

You’ll find the latest research and recommendations on supplements, energy drinks, organic foods, fluid intake, popular diets, carbohydrate and protein intake, training, competition, fat reduction, and muscle gain. Whether you’re seeking advice on getting energized for exercise or improving your health and performance, Nancy Clark’s Sports Nutrition Guidebook has the answers you can trust.

Learn more about the book by viewing the trailer.

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iPhone, iPod touch, or iPad-compatible app contains 71 recipes searchable across calories, carbohydrate, fat, protein, special diets, and nutrient timing to find the perfect dish. This Item is currently out of stock Nancy Clark’s Sports Nutrition Guidebook includes the latest research on hydration, vitamins, supplements, energy drinks, organic foods, and balancing carbohydrate and protein intake for exercise and competition. This Item is currently out of stock Nancy Clark’s Sports Nutrition Guidebook includes the latest research on hydration, vitamins, supplements, energy drinks, organic foods, and balancing carbohydrate and protein intake for exercise and competition. This Item is currently out of stock

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Five nutrition principles all strength trainers should follow

Creator of Power Eating program reveals secrets to superior performance

Athletes serious about improving their physique and strength-training performance will do anything they can to achieve success. But, according to Susan Kleiner, a registered dietitian and creator of the widely popular Power Eating program, advice given to strength trainers is often a confusing mix of fact and fiction. In the new edition of her book, Power Eating, Kleiner separates fact from fiction by sharing five principles that all strength trainers can follow to get in shape and achieve their personal best in performance.

Eat enough calories. “A key to feeling energized is to eat the right amount of calories to power your body for hard training,” Kleiner says. “A lack of calories will definitely make you feel like a wet dishrag by the end of your workout.” Very low-calorie diets followed for longer than two weeks can be hazardous to an athlete’s health, and they don’t provide the dietary reference intakes (DRIs) of enough of the nutrients needed for basic health. Studies have shown that athletes in particular may have to exceed the DRI of many nutrients. Some competitive bodybuilders have estimated their caloric intake to be greater than 6,000 calories a day during the off-season—roughly three times the DRI for the average person (2,000 calories a day for women and 2,700 calories a day for men). “How much you need of each nutrient depends on a number of factors, including your age and sex, how hard you train, and whether you are a competitive or recreational strength trainer,” Kleiner explains.Eat the carbohydrate you need. “Most athletes don’t eat enough carbohydrate, the primary fuel for the body,” Kleiner says. “They often follow diets in which only half of the total daily calories come from carbohydrate, but 6 to 7 grams of carbohydrate per kilogram of body weight are required daily.” A majority of bodybuilders practice low-carbohydrate dieting because they believe it promotes faster weight loss. But these diets deplete glycogen, the body’s storage form of carbohydrate. Once glycogen stores are emptied, the body starts burning protein from tissues, including muscle tissue, to meet energy demands. “Many fitness-minded people think carbs will make them fat—a myth that is partially responsible for unbalanced strength-training diets, which are typically too high in protein,” Kleiner says. “The real story on carbohydrate for weight control and muscle building is that you should select whole-food carbohydrate—natural, complex carbohydrate as close to its natural state as possible—instead of refined, processed carbohydrate.”Vary your diet. “Bodybuilding diets, especially precontest diets, tend to be monotonous; the same foods show up on the plate day after day,” Kleiner says. “The problem with such a diet is that it lacks variety, and without a variety of foods, you miss out on nutrients essential for peak health.” Most bodybuilders don’t eat much fruit, dairy products, and red meat. Fruit is packed with health-building antioxidants, and dairy products supply important nutrients such as bone-building calcium and bioactive proteins that promote lean muscle growth. Red meat is also an important source of vital minerals such as iron and zinc. “When people limit or eliminate such foods from their diets, potentially serious deficiencies begin to show up,” Kleiner explains. “In studies conducted by me and others, the most common deficiencies observed are those of calcium and zinc, particularly during the precompetition season. Deficits of these minerals can harm health and performance.”Time and combine your food and nutrients. “To achieve superb physique and maximum performance, forgo the usual approach of three meals a day,” Kleiner says. “Active people must fuel themselves throughout the day, eating small meals and snacks every two to three hours, preferably timed around their workout schedules.” When eating multiple meals, combine protein with carbohydrate and fat. By including small amounts of protein in meals and snacks, athletes can control appetite, feed muscles more efficiently, and maintain muscle when they’re trying to lose fat. “The bottom line is that eating small, frequent meals throughout the day is the best fat-burning, muscle-building strategy you can integrate into your lifestyle,” Kleiner says.Use a food plan. “Any nutrition program aimed at losing body fat and building muscle should be based on a food plan that emphasizes lean protein, natural carbohydrate, and good fat,” Kleiner says. “It should also include sample menus and recipes as well as information on making healthy selections that are personalized to an athlete’s lifestyle.” Kleiner adds that a food plan should be neither so restrictive that it invites failure nor so unstructured as to be confusing. “You have to be exact about what you eat, and you need to make the right choices. Each calorie that you put into your mouth has to be results oriented,” Kleiner explains.

These are the same principles Kleiner has advocated for world-class athletes, Olympic contenders, and recreational strength trainers for more than 25 years.

More than 100,000 people have turned to Power Eating and its proven nutrition strategies for gaining power, reducing body fat, building muscle, and enhancing training results. The new fourth edition offers a scientific blueprint for helping strength and power athletes achieve superior performance.

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Hydration, heat, nutrition for endurance events

Good safety practices should be used when training endurance athletes. Because of the high volume of work, special problems arise. A proper training program balances intensity and volume and provides event-specific flexibility, strength, and drill training. Coaches should give thought to the training surface and appropriate footwear for the athletes given the conditions.

Because most endurance training programs include a great deal of training off the track, safety when running near traffic and other hazards is an important consideration. Overtraining and heat-related problems are significant issues in these events; avoiding these situations is an important part of safety and injury prevention. Hydration, environmental conditions, and nutrition are also more significant in the endurance events because of their longer duration.

Dehydration thickens the blood and makes it harder to pump (think water versus molasses). On average, males can lose 2.0 liters (or quarts) per hour through sweating; females, 1.1 liters per hour. In warm weather athletes should restrict their fluid loss to 1 to 2 percent of their total body weight. Each pound (about 0.5 kg) of fluid loss needs to be replaced by 16 to 24 ounces (473 to 710 ml) of water. Runners should consume 16 to 24 ounces (473 to 710 ml) of fluid containing electrolytes per pound (about 0.5 kg) of body weight lost during exercise. These figures are estimates; there is great variability among individuals and environmental conditions. In addition, for optimal performance for events lasting longer than one hour, athletes should consume 120 to 400 calories per hour during the event either as fluids or in addition to fluids.

Performance in endurance events can be significantly affected by extremes in climate. In regard to heat, the longer the event, the greater the impact. In the case of the marathon, for every 5 degrees the temperature rises above 50 degrees Fahrenheit (or about 3 degrees it rises above 10 °C), the athlete’s final time typically increases by about 0.5 percent. If the temperature is above 98.6 degrees Fahrenheit (37 °C) and the humidity is above 70 percent, running outside should be avoided. The body sheds heat through the evaporation of sweat. When humidity is high, evaporative cooling is inhibited, and so is the body’s ability to shed heat.

Great care needs to be taken when an athlete travels from a cooler climate to a warmer climate or when the daily temperature rises significantly. The body takes 5 to 8 days to significantly acclimatize to warmer conditions, and 14 days to reach near-maximal acclimatization.

Heatstroke is a medical emergency and should be treated immediately by getting the runner into an air-conditioned, or at least cooler and shaded, environment. Attempts to bring down the athlete’s body temperature through the use of water and ice should begin immediately while medical assistance is sought.

Inadequate body iron reserves affect the athlete’s adaptation to training. Low iron limits the quality and quantity of high-level endurance work output. Fitness is built by the athlete adapting to the training stimulus, and this adaptation requires iron.

Iron deficiency, which is more common in female athletes, can cause overtraining symptoms. A decrease in iron stores can cause a decrease in aerobic capacity since iron is part of hemoglobin, which carries 98.5 percent of blood’s oxygen, and more than half of the enzymes of aerobic metabolism contain iron.

Excessive impact stress can cause hemolysis due to extravascular compression and intravascular acidosis, which can cause the following to occur:

Increase in blood acidityIncrease in red blood cell transit velocityDecrease of the mean life of red blood cells from a normal 120 days to approximately 80 days

Iron depletion is a decrease in serum ferritin levels, which inhibits erythrocyte and hemoglobin levels in the blood. An athlete’s ferritin level is the most accurate indicator of his or her iron stores. Distance athletes who run 60 miles or more per week should have their ferritin levels monitored at least twice a year. If blood tests reveal an iron deficiency, the athlete should reduce training volume and consult a sport science doctor or nutritionist to begin a program designed to increase iron stores through good nutrition and iron supplementation.

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