Nutrition

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Nutrition

• KNR 240

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Objectives

• What are the different kinds of nutrients, and
  what functions do they perform in the body?
• How does the body use the foods we consume for
  fuel?
• What percentages of calories come from protein,
  fats, and carbohydrates in the average American
  diet, and what percentages of these nutrients are
  recommended?

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Objectives

• What guidelines have been developed to help
  people choose a healthy diet, avoid nutritional
  deficiencies, and protect themselves from
  diet-related chronic diseases?
• How can people adapt nutritional information to
  their own lives and circumstances?

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Nutrition is

• A vitally important component of wellness.
• Closely linked with certain diseases, disabling
  conditions, and other health problems.
• THERE IS A LINK BETWEEN LIFETIME NUTRITIONAL
  HABITS AND THESE DISEASES!!

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However

• A WELL PLANNED DIET IN CONJUNCTION WITH A FITNESS
  PROGRAM CAN HELP PREVENT SUCH CONDITIONS AND EVEN
  REVERSE SOME OF THEM!!

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So, the goals of this section are to

• Understand the basic principles of nutrition.
• Learn the six classes of essential nutrients,
• Learn the role of these essential nutrients in
  the body.
• Understand the guidelines that are available to
  help YOU design a food plan for health and
  wellness for yourself..
• Understand the guidelines that are available to
  help YOU design a food plan for health and
  wellness for your athletes

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FOODS ARE COMPOSED OF

• Proteins
• Carbohydrates
• Fats
• Vitamins
• Minerals
• Water

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ESSENTIAL NUTRIENTS

• Are nutrients that we must include in our diet.
  Our body does not manufacture them.

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Nutrition

• Nutrients are released into the body by the
  process of DIGESTION
• The Energy in Foods is measured in kilocalories.
• 1 kcal represents the amount of heat it takes to
  raise the temp. of 1 kg of water 1 degree C.

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The Process of Digestion
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SIX CLASSES OF ESSENTIAL NUTRIENTS

• 3 PROVIDE ENERGY
• fat
• protein
• carbohydrates

• 3 DO NOT PROVIDE ENERGY
• vitamins
• minerals
• water

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Food Energy

• Fats
• Provide the most energy.
• 9 calories per gram.
• Carbohydrates
• Provide 4 calories per gram
• Proteins
• Provide 4 calories per gram.
• Alcohol
• Although alcohol is not an essential nutrient, it
  does provide energy.
• Alcohol provides 7 calories per gram

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Nutrients

• Although vitamins, minerals, and water do not
  provide energy, they are still VITAL!
• The body is approximately 60 water, and can
  survive only a few days without it.
• All foods are combinations of the different kinds
  of nutrients.

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Energy and ATP Production

• Metabolism is---The sum of all the chemical
  processes necessary to maintain the body.
• Energy is required to fuel vital body functions.
• The rate at which your body uses energy (its
  metabolic rate) depends on your level of
  activity.

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So, where does the energy come from?????

• The body converts chemical energy from food into
  substances that cells can use as fuel.
• These fuels can be used immediately or stored.

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Carbohydrates

• During digestion, most carbohydrates are broken
  down into glucose.
• Some glucose remains in the blood and some is
  converted to glycogen and is stored in the liver,
  muscles, and kidneys.
• Remaining glucose is converted to fat and stored
  in adipose.

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Protein

• Used primarily for building of new tissues.
• Can be broken down for energy when other fuels
  not available.
• Excess can be converted and stored as fat.

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Fat

• Excess fat is stored as fat.

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ATP

• Adenosine triphosphate- Is the basic form of
  energy used by the cells.
• ATP is The energy currency of cells
• When a cell needs energy, it breaks down ATP,
  which is a process that releases energy in the
  only form the cell can use directly.
• Cells do store a minute amount of ATP, but when
  more is needed, it is created through the
  chemical reactions that break down the bodys
  stored fuels-glucose, glycogen, and fat.
• Metabolic pathway map.

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Exercise and the three energy systems

• The muscles in your body have three energy
  systems by which they can create ATP and fuel
  cellular activity.
• These systems use different fuels and chemical
  processes, and they perform different, specific
  functions during exercise.

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Immediate energy systemATP-CP stores

• Very short duration (lt10sec.)
• Very high intensity
• Rapid ATP production
• Uses existing ATP, CP
• Anaerobic.

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Non-oxidative (Anaeroic)Lactate Path

• Short duration (10sec to 2 min.)
• High intensity
• Rapid rate of production of ATP
• Glucose and glycogen used in process called
  glycolysis
• Anaerobic-no oxygen used.
• Produces lactic acid

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Oxidative (Aerobic)

• Used in activities longer than 2 minutes
• Low to moderate intensity
• Slower production of ATP, but is prolonged
• Fuel used is glycogen, glucose, fat, and protein
• Oxygen is required (aerobic)
• ATP production occurs in the mitochondria. The
  mitochondria can use either glucose or fats to
  produce ATP. The fuel used depends on the
  intensity of the exercise.

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Oxidative-Aerobic continued

• Maximal Oxygen Consumption (VO2 max).
• Determined by the ability of the body to uptake,
  distribute, and utilize oxygen.
• Determined partly on genetics, and partly on
  fitness status.
• Considered the best overall measure of the
  capacity of the CR system.

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Energy systems in combination

• Your body typically uses all three energy systems
  when you exercise.
• The intensity and duration of the activity will
  determine which system predominates.
• Fitness status
• Previous diet
• See Figure 9.8 p. 304
• Fat and carbohydrate are the primary fuels for
  endurance exercise.
• See Table 9.9, p. 304 for substrate stores.

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So.

• How does one choose foods that will best fuel
  their body?
• From an energy perspective
• From a health/wellness/disease prevention
  perspective????

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Dietary Guidelines for Health and Disease
Prevention

• Dietary Guidelines for Americans
• Aim for Fitness
• Build a healthy base
• Choose sensibly

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Aim for Fitness

• 1. Aim for a healthy weight
• As previously discussed, 55 of adults and 22 of
  children and adolescents are overweight and obese
  in the US today.
• OW and OB are linked with HTN, heart disease,
  stroke, diabetes, certain cancers, arthritis, and
  other types of illnesses.
• Calories inCalories out

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Aim for Fitness

• 2. Be physically active every day.
• More than 60 of American adults do not engage in
  recommended amounts of physical activity.
• 25 of American adults are not active at all.
• Only about 15 of American adults engage in
  regular, daily, moderate physical activity for at
  least 30 minutes per day.
• Refer to Table 1.1, p. 7 in text.

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Build a Healthy Base

• 3. Let the Food Guide Pyramid
• be your guide

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Build a Healthy Base

• The FGP was developed by the USDA to help
  consumers translate nutrient recommendations into
  a plan for healthy eating.
• Range of serving sizes from six food groups.
• Total number of servings needed depends on
  caloric needs.
• 1600-2800 calories/day
• See Box 9.3, p. 289.

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Build a Healthy Base

• Within each food group, foods vary in the amount
  of nutrients and calories they provide.
• Not all foods are created equal!
• All foods can fit!
• Best choices emphasize nutrient densitythose
  that are high in nutrients relative to the amount
  of calories they contain.
• E.g. A slice of whole grain bread compared to a
  croissant.

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Build a Healthy Base
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Build a Healthy Base
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Build a Healthy Base
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Build a Healthy Base

• 4. Choose a variety of Grains daily, especially
  whole grains.
• Most foods chosen each day should come from this
  segment of the pyramid.
• Choosing more whole-grain products will increase
  consumption of total carbohydrates and fiber,
  and will decrease fat consumption.
• Choose unrefined, whole grains over refined,
  processed foods.
• Recommendation is for AT LEAST 55 of total
  calories to come from carbohydrates, with no more
  than 10-15 of these to come from simple
  carbohydrate sources.

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Simple Carbohydrates

• Contain only one or two sugar units in each
  molecule.
• One-unit molecule MONOSACCHARIDE
• glucose, fructose, and galactose
• Two unit molecule DISACCHARIDE.
• These include
• sucrose (table sugar) fructose glucose
• maltose (malt sugar) glucose glucose
• lactose (milk sugar) glucose galactose.
• Simple carbs provide much of the sweetness in
  foods.

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Complex Carbohydrates

• Starches and most types of dietary fiber.
• SOLUBLE slows the absorption of glucose, binds
  cholesterol, which reduces serum cholesterol and
  CAD risk.
• INSOLUBLE binds water, making feces bulkier and
  softer
• Both kinds of fiber contribute to disease
  prevention.
• A diet high in soluble fiber can help people
  manage diabetes and high chol. levels.
• A diet high in insoluble fiber can help prevent
  constipation, hemorrhoids, diverticulitis and
  colon and rectal cancers
• Some research suggests it may also reverse pre-CA
  changes.
• Consist of chains of many glucose molecules.
• Are called POLYSACCHARIDES.
• All plant foods contain some dietary fiber.
• Those particularly rich in fiber include fruits,
  legumes, oats (oat bran), barley, and psyllium.
• Wheat (bran) cereals, grains, and veggies are
  good sources of insoluable fiber
• See Table 9.3, p. 292
• Recommendation for daily fiber intake is 20-35
  grams. Current intake is about 14 grams.

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Refined vs. Unrefined

• The processing of packaged foods can remove
  fiber.
• Refined carbohydrates retain all the calories,
  but are lower in fiber, vitamins, and minerals.
• Unrefined carbohydrates take longer to chew and
  digest, and enter the blood more slowly.
• These have many health benefits.
• Feel fuller longer, more anti-oxidant vitamins
  and phytochemicals, and decreased risk of
  diabetes.

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Build a Healthy Base

• 5. Choose a variety of fruits and vegetables
  daily.
• Fruits and veges are complex foods containing
  more than 100 beneficial vitamins, minerals,
  fiber, and other substances such as
  phytochemicals.

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Build a Healthy Base

• Phytochemicals and Antioxidants
• Much new research being done on these.
• Are said to aid in the preservation of the bodys
  healthy cells.
• Free-radicals damage cell membranes and cause
  gene mutations.

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Build a Healthy Base

• A Free Radical is a chemically unstable molecule
  that is missing an electron. It will react with
  any molecule it encounters from which it can take
  an electron. (For example fats, proteins and DNA.
  This damages cell membranes and mutates genes.
• Therefore, they have been implicated in aging,
  cancer, cardiovascular disease, and degenerative
  diseases such as arthritis.
• Environmental factors such as cigarette smoking,
  exhaust fumes, radiation, excessive sun exposure,
  certain drugs, and stress can increase free
  radical production.
• Antioxidants react with free radicals and donate
  lost electrons. They help by blocking the
  formation and action of free radicals and repair
  the damage they cause.
• Vitamin C, Vitamin A (beta-carotene), Vitamin E
  and selenium are a few examples of antioxidants.

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Build a Healthy Base

• Phytochemicals
• Anti-oxidants are a particular type of
  phytochemical which is a substance found in plant
  foods that may help prevent chronic diseases.
• Examples of phytochemicals include sulforaphane
  (found in cruciferous veges), allyl sulfides, and
  isoflavones.
• See handout

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Build a Healthy Base

• 6. Keep food safe to eat.
• Food-borne illness is caused by eating foods that
  contain harmful bacteria, toxins, parasites,
  viruses, or chemical contaminants.
• S/S of having eaten unsafe food may appear within
  half an hour, or may not develop for up to 3
  weeks.
• Refer to p. 294 for steps to follow to keep food
  safe.

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Choose Sensibly

• 7. Choose a diet that is low in saturated fat
  and cholesterol and moderate in total fat.
• Most fats in food are in the form of
  triglycerides.
• Triglycerides are composed of a glycerine
  molecule (an alcohol) plus three fatty acid
  chains.
• Fatty acids are made up of a chain of carbon
  atoms with oxygen attached at the end and
  hydrogen atoms attached along the length of the
  chain.
• Fatty acids differ in the length of their carbon
  atom chains.

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Choose Sensibly
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Choose Sensibly

• Cholesterol
• Is a type of fat (sterol) found in animal
  products only.
• It is manufactured by the body in the liver.
• High levels of cholesterol are linked to coronary
  artery disease.
• RDA for cholesterol is less than 300 mg./day

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Choose Sensibly

• Fatty acids also differ by their degree of
  saturation.
• Fats are classified as saturated or unsaturated
  depending on the amount of double bonds located
  between the carbon atoms.
• If no double bonds exist between carbons, a fat
  is classified as Saturated.
• Fats are unsaturated depending on the amount of
  double bonds between C atoms.
• FAs with one double bond are called
  MONOUNSATURATED.
• FAs with two or more double bonds are called
  POLYUNSATURATED.

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Choose Sensibly

• Main sources of saturated fats in the American
  diet are hamburger, steak, roast, poultry skin,
  ice cream, and many baked products, cheese,
  coconut and palm oil, Crisco and butter.
• These are solid at room temperature.

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Choose Sensibly

• Foods that are classified as mono or poly
  unsaturated typically come from plant sources.
• They are liquid at room temperature. This is
  because there is not as many hydrogen bonds to
  the carbons.
• Main sources include oils, except palm and
  coconut oil.
• Monosolive, canola, safflower and peanut
• Polyscorn, soybean and cottonseed

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Choose Sensibly
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Choose Sensibly

• The process of adding hydrogen to an oil to
  improve the texture of foods and increase shelf
  life. Also helps the fat be more capable of
  withstanding high temperatures for frying.
• Turns a liquid oil into a solid.
• Turns the double bonds in unsaturated fats to
  single bonds, thereby increasing the degree of
  saturation and producing a more solid fat from a
  liquid oil.
• Margarine...
• The process of hydrogenation produces fatty acids
  that are not quite the same as a saturated fat,
  and are referred to as trans-fatty acids.
• Read on nutrition labels as hydrogenated or
  partially-hydrogenated vegetable oils.
• Leads to health risk due to increase in
  cholesterol level.
• Refer to Figure 9.4, p. 295 for fatty acid
  structure and food sources.

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Chemical Structure of Fatty Acids
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Choose Sensibly
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Choose Sensibly

• Omega-3 Fatty Acids
• Is a form of polyunsaturated fat.
• Found in many kinds of fish.
• May play a role in CAD prevention.
• Has been found to reduce the tendency of the
  blood to clot, to decrease inflammatory
  responses, helps heart to beat in a steady
  rhythm, and to increase HDL levels in women.
• Recommendations is to have two or more servings
  fish/week.
• Examples salmon, tuna, trout, mackerel, herring,
  sardines, and anchovies.
• Plant sources include dark green leafy veges,
  walnuts, and flax seeds.

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Choosing Sensibly

• Calculating Fat , Reading Food Labels
• Find the food nutrition label.
• Look at the total number of calories and fat
  grams in one serving.
• Multiply the number of fat grams by 9.
• Divide that number by the number of total
  calories.
• Result is percent of calories that product has
  that come from a fat.
• Refer to Figure 9.3, p. 293.

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Example Ho-Hos

• Serving size 2 rolls.
• Calories per serving 290.
• Total Fat per serving 15 grams
• Saturated fat 7 grams.
• Calculate 15 X 9 135, thus 135 calories are
  fat calories.
• 135 / 290 0.465 or 47.
• SO, 47 of the calories in a HO-HO is from fat,
  and 22 is from Sat. fat. YUCK!!!

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Choose Sensibly

• High saturated and trans-fat in the diet
  increases level of serum cholesterol and LDL, and
  lowers HDL.
• High LDL leads to increased risk of CAD.
• Consumption of unsaturated fats may lead to a
  decrease in total serum cholesterol
• Mono-unsaturated fats may lower total cholesterol
  and LDL, yet have no effect or may raise HDL
• Poly-unsaturated fats may also lower total
  cholesterol and LDL, but tend to also lower HDL
• Diet high in fat may also lead to cancer and
  weight management problems.

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Choose Sensibly

• To lower trans fats, decrease intake of
• Deep-fat fried foods and baked goods made with
  hydrogenated vegetable oils.
• Choose
• Liquid oils rather than margarine or shortening
  for cooking, and flavor tub or squeeze margarines
  or those labeled low-trans or trans-free over
  standard stick margarines.
• Remember, the softer or more liquid the fat is,
  the less saturated and trans fat it is likely to
  contain.

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Choose Sensibly Reducing the fat in your diet

• See list on p. 296, text.
• Be moderate in your intake of fast foods,
  commercially prepared baked goods and desserts,
  deep-fried foods, meat, poultry, nuts and seeds,
  and regular dairy products.
• Season vegetables, seafood, and meats with herbs
  and spices rather than with creamy sauces,
  butter, or margarine.
• Try non-fat mayonnaise and fat-free salad
  dressings.
• Steam, boil, bake, or microwave vegetables.
• Roast, bake, or broil meats, poultry, or fish so
  that fat drips away as it cooks.
• Use non-stick cookware so added fat is not
  necessary.
• Make gravies with de-fatted broth.
• Substitute egg whites or egg beaters for whole
  eggs.
• Substitute liquid butter buds, applesauce or
  non-fat yogurt for butter or margarine in baking.

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Choose Sensibly Fat Intake Recommendations

• Humans only need a single tablespoon of vegetable
  oil per day (15 grams) to get their essential FA.
• Linoleic and alpha-linolenic
• These are polyunsaturated fats.
• The average American consumes about 32-38 of
  their calories from fat (75 grams or 5 tbls.)
• Over recent years, the percentage of calories
  from fat has decreased, but, because of increased
  caloric consumption over these past recent years,
  we are actually consuming more total grams of
  fat.
• Recommendations No more than 30 of calories
  from fat, and no more than 7-10 from saturated
  fat sources, up to 10 from polyunsaturated
  sources, and up to 20 from monounsaturated
  sources.

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Food For Thought..

• The text states that the goal is to end up with
  fewer than 30 of your total days calories to
  come from fat.
• I wonder if it should not be to try to keep the
  fat in each individual food from contributing
  more than 30 of calories.
• Also, is 30 too high????? I wonder.

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Choose Sensibly

• 8. Choose beverages and foods to moderate your
  intake of sugars.
• As discussed previously, sugars are classified as
  simple carbohydrates, whereas starch is defined
  as a complex carbohydrate.
• Sugars and starches occur naturally in many
  foodsincluding milk, fruits, some vegetables,
  bread, cereals, and grains.
• These foods, however, provide many important
  nutrients.
• On the other hand, so-called added sugars-supply
  added calories, but few nutrients.
• Foods rich in added sugars include things like
  soft drinks and desserts.

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Choose Sensibly

• How much sugar is added to this???

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Choose Sensibly

• A sugar by any other name
• Read the label to locate hidden sugars in the
  foods you consume.
• Sugars are listed by many different names,
  including brown sugar, corn sweetener, corn
  syrup, fructose, fruit juice concentrate, glucose
  or dextrose, high-fructose corn syrup, honey,
  lactose, maltose, molasses, raw sugar, table
  sugar, or sucrose, and syrup.
• If one of these appears near the top of the
  ingredients list, the food is probably high in
  added sugars.

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Choose Sensibly

• Recommendations
• The FGP places foods high in added sugars at the
  top of the pyramid.
• Average American intake of added sugars males-22
  tsps., females, 16 tsps.
• This does not include naturally occuring sugars
  found in foods such as milk and fruits.
• The USDA recommendation
• 1600 calories/day no more than 6 tsp/day
• 2200 calories/day no more than 12 tsp/day
• 2800 calories/day no more than 18 tsp/day

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Choose Sensibly

• Rationale
• Sugars and starches can both promote tooth decay.
• Sugars increase serum triglyceride levels.
• Added calories for little nutrient density.

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Choose Sensibly

• 9. Choose and prepare foods with less salt.
• The human body requires 500 mg Na/day.
• Average American consumes about 4,000-6,000
  mg/day.
• High Na intake associated with HTN.
• USDA recommendation no more than 2,400 mg/day or
  about 1 tsp. NaCl/day.
• Refer to Table 9.4, p. 297 text for sources of
  salt.

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Choose Sensibly

• Tips for reducing salt intake
• Read food labels.
• Choose more fresh fruits and veges.
• Choose fresh or frozen fish, shellfish, poultry,
  and meat. They are lower in salt than most
  canned and processed forms of meats.
• Reduce salt use during cooking. Substitute herbs
  and low-Na seasonings.
• Avoid the salt shaker, and limit use of
  condiments such as soy sauce, ketchup, mustard,
  pickles, and olives.
• Limit intake of foods with visible salt on them,
  such as snack chips, salted nuts, cracker, etc.

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Choose Sensibly

• 10. If you drink alcoholic beverages, do so in
  moderation.
• Alcohol supplies calories with very little
  nutrition. (7 calories/gm).
• Alcohol is linked with many health problems,
  birth defects, accidents, violent crimes, and
  addiction.
• See list on p. 298 for USDA identified groups
  that should abstain from alcohol.

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Choose Sensibly

• Moderate intake means
• No more than two drinks a day for men, and one
  drink a day for women.
• One serving of alcohol, commonly called a drink
  delivers 0.5 ounces of pure alcohol.
• 12 oz regular beer (150 calories)
• 5 oz wine (100 calories)
• 1.5 oz of 80-proof distilled spirits (100 cals)
• 10 oz of wine cooler (140 calories)
• See Table 9.5 for BAC and symptoms.

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10 Cardinal Sports-Nutrition Principles that are
Applicable to the Athlete

• Prudent diet is the cornerstone
• Increase total energy intake
• Keep the dietary carbohydrate intake high
  (55-70) during training
• Drink large amounts of fluid during training and
  the event
• Keep a close watch on possible iron deficiency
• Vitamin and mineral supplements are not needed
• Protein supplements do not benefit the athlete
• Rest and emphasize carbohydrates before long
  endurance events
• Use of ergogenic aids is unethical
• Fat loading is not recommended for enhanced
  performance or health

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Prudent diet is the cornerstone

• For all Americans, physically active or not, the
  prudent diet is the recommendation.
• The prudent diet adheres to recommendations
  from the National Research Council, and the
  USDAs Dietary Guidelines for Americans
• RDAs provided in text on pages 284-285.

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Prudent diet is the cornerstone

• Dietary practices of athletes
• Athletes who purposely keep their weight below
  natural weight for competition tend to have
  reported caloric intakes that fall way below
  calculated energy expenditure.
• Athletes in sports that emphasize leanness
  (wrestlers, gymnasts, body builders, runners, and
  ballet dancers) are exceptionally preoccupied
  with weight and tend to use unhealthy methods for
  weight control, tend toward eating disorders and
  demonstrate poor nutrition practices.
• Protein intake in athletes ranges form 10 36
  of total calories. Athletes are not much
  different than the non-athletic population, who
  also tends to consume nearly double the RDA for
  protein.
• Fat intake averages 36 of energy intake in
  athletes. Power and strength athletes tended to
  have higher fat intakes than endurance athletes,
  and this is often associated with the higher
  protein intake.
• Carbohydrate provides about 46 of energy
  consumed by athletes. Tri-athletes tended to
  have higher carbohydrate intake than the other
  athletes.
• Vitamin and mineral intakes tended to be higher
  than the RDA, because the athletes ate more food
  than inactive people. There is also widespread
  use of supplements in athletes. However, sports
  emphasizing leanness were found to consume
  insufficient quantities of vitamins and minerals.
• In general, the quality of the athletes diet is
  somewhat similar to that of the general
  population.

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Increase total energy intake

• If a person is of normal body weight, and they
  exercise regularly, that persons energy
  consumption will need to be higher than that of
  the average sedentary individual to maintain body
  weight.
• The amount and intensity of training and body
  size are the chief determinants of the energy
  requirements of the athlete.
• See Table 9.7, p. 301

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Keep the dietary carbohydrate intake high
(55-70) during training

• There are several basic principles regarding the
  relationship between exercise and dietary
  carbohydrate and muscle glycogen.
• Body glycogen stores play an important role in
  hard exercise (70-85 of VO2 max) that is either
  prolonged and continuous or of an extended
  intermittent mixed anaerobic-aerobic nature.
• There are limited CHO stores in the body, and the
  body adapts in various ways to maximize its use
  of these stores.
• Exhaustion during prolonged, hard exercise is
  tied to low muscle glycogen levels.
• When muscle and liver glycogen stores are low, a
  high work output cannot be maintained. Hitting
  the Wall
• During the first hour of hard exercise, most CHO
  and fat come from within the muscle. As exercise
  continues beyond one hour, more demand is placed
  upon adipose tissue fat fuel sources and blood
  glucose as muscle glycogen levels begin to be
  depleted. The longer the exercise, the greater
  the need for glucose from the liver.
• During training, muscle glycogen stores undergo
  rapid day-to-day fluctuation.
• Rapid restoration of muscle glycogen stores is
  essential to those athletes that compete or train
  repeatedly on same or consecutive days.
• Glycemic indexwhich foods to choose pre, during
  and post event/training. See Box 9.5, p. 309.
• Recommendation athletes in heavy training
  should consume a diet of close to 70 CHO, or
  about 525 grams per 3000 calories). This will
  restore muscle glycogen within 24 hours, enabling
  the athlete to continue heavy training. This is
  especially important after race events and long,
  intense training bouts.
• See table 9.10 for listing of high CHO foods.

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Drink large amounts of fluid during training and
the event

• As little as a 2 drop in body weight caused by
  water loss (primarily from sweat) can reduce
  exercise capacity.
• If you are thirsty, you are already dehydrated.
• Recommendation Drink 2 cups of water
  immediately before exercise, 1 cup every 15
  minutes during exercise, and then 2 more cups
  after the session.
• If exercising longer than one hour, then consider
  carbohydrate and sodium drinks.
• Loss of body water from sweating beyond 2 of
  body weight will significantly impair endurance
  capacity, through elevation of body temperature
  and decreased cardiac output. When sweat output
  exceeds water intake, both intracellular and
  extra-cellular water levels fall, and plasma
  volume decreases. This results in an increase in
  body temperature, a decrease in the ability of
  the heart to pump blood, and a decrease in
  endurance performance.
• Intracellular fluid accounts for 67,
  Interstitial (between cells) fluid accounts for
  27 and plasma volume accounts for 6 of an
  average 70 kg individual with 42 liters of body
  water. (60 of body weight.)
• Acclimatization process occurs as people train in
  the heat. The individual will have a higher
  plasma volume and sweat glands will produce more
  sweat earlier in the exercise session, with less
  loss of sodium. Body temp and HR do not rise as
  strongly in those who are acclimatized.
• When the body loses water during prolonged
  exercise, and it is not replenished, there is a
  gradual decrease in heart stroke volume, and a
  corresponding increase in heart rate.
• Box 9.6, p. 316- ACSM position stand on fluid
  replacement.
• Should electrolytes and carbohydrates be used
  during exercise? When exercise exceeds one hour,
  the exercisers fluid, electrolyte, and
  carbohydrate requirements can be met
  simultaneously by ingesting 600-1200 ml/hour of a
  solution containing 4-8 CHO and 0.5-0.7 grams of
  sodium per liter.

78
Keep a close watch on possible iron deficiency

• Some athletes, especially females, may be prone
  to iron deficiency.
• Recommendation is to not routinely take iron
  supplements without medical supervision, but to
  increase iron consumption by eating foods high in
  iron.
• Heme-Fe and non-heme Fe.
• Vitamin C
• See table 9.15, p. 322 for foods with various
  iron contents.

79
Vitamin and mineral supplements are not needed

• Most studies show that the intake of major
  vitamins and minerals by people who exercise is
  above recommended levels.
• The increase in food eaten by exercisers provides
  the extra vitamins and minerals, particularly if
  the diet consists of a high-carbohydrate,
  moderate protein, low-fat menu.
• Even though many coaches and fitness journals
  urge supplementation to boost or maximize
  performance, the ACSM, the ADA, and Dietitians of
  Canada have made a statement that no vitamin or
  mineral supplements are required if an athlete is
  consuming adequate energy from a variety of
  foods.
• The AMA, the ADA, the American institute of
  nutrition, the food and nutrition board, and the
  national council against health fraud, have
  submitted formal statements to the effect that
  there are no demonstrated benefits of
  self-supplementation beyond the RDA, except in
  special cases. submitted a formal statement to
  the effect that there are no demonstrated
  benefits of self-supplementation beyond the RDA,
  except in special cases.
• Recommendation The best nutritional strategy
  for promotion optimal health and reducing the
  risk of chronic disease is to obtain adequate
  nutrients from a wide variety of foods.
• High intake of vitamins and minerals even could
  be problematic, especially with the fat soluble
  vitamins A,D,E, and K. Furthermore, excess of
  one nutrient can cause a deficiency in another
  nutrient.
• Research shows that between 50 and 80 of elite
  athletes use vitamin and mineral supplements on a
  regular basis.

80
Protein supplements do not benefit the athlete

• Many people who exercise, especially weight
  lifters, feel that consumption of high-protein
  foods and protein supplements is necessary to
  build muscle mass.
• The average sedentary person has been advised to
  consume 0.8 gram of protein per kilogram of body
  weight. Research is showing that highly active
  people may need 50-125 more than this because
  5-15 of the energy required for long endurance
  exercise or weight lifting comes from protein,
  and extra protein is needed for muscle protein
  synthesis. However, most experts feel that the
  traditional food supply provides all of the
  protein needed, even for the athletes during
  active muscle-building phasessupplements are not
  needed.
• The American Dietetic Association has advised
  that endurance athletes take in 1.2-1.4 g/kg
  protein daily. However, most endurance athletes
  are already getting this much protein and do not
  need to supplement their diets with protein
  powder or concern themselves with eating
  high-protein foods.
• Most strength and power athletes can enhance
  muscle development when dietary protein intake
  ranges between 1.6 and 1.7 g/kg. There is no
  evidence that very high protein intakes
  (gt2g/kg/day) are either necessary or beneficial.
• There is little scientific evidence that amino
  acid supplementation enhances the physiological
  responses to strength training when adequate
  diets are consumed.
• See Table 9.17 for a list of the protein content
  of common foods.
• Refer to Box 9.7, p. 328 for special issues for
  Vegetarians.

81
Rest and emphasize carbohydrates before long
endurance events

• When an event lasts longer than 60-90 minutes, it
  is recommended to taper off the exercise
  gradually during the week before the event, while
  consuming more than 70 CHO during the 3 days
  before the event. If the event is less than 60
  minutes, carbohydrate loading is not necessary.
• See page 329 for CHO loading.
• For the pre-event meal, most sports-nutrition
  experts advise one or two glasses of water,
  followed within 20-30 minutes by a light (500-800
  kcal) meal of rapidly digestible, low-fiber
  starch (cream of wheat hot cereal, white bread,
  bagels, pasta, refined cereals, low glycemic
  index foods). The food should be consumed 3-5
  hours before the event, so the stomach will be
  empty at the time of competition to avoid
  abdominal fullness or cramping.
• The use of proteins, fats, known gas-forming
  foods, high-fiber foods, and foods known to act
  as laxatives is not recommended.

82
Use of ergogenic aids is unethical

• Five categories of ergogenic aids
• Nutritional aids
• Pharmacological aids
• Physiological aids
• Psychological aids
• Mechanical aids
• See Table 9.18, p. 332 for products, claims, and
  fact on their ergogenic ability.

83
Fat loading is not recommended for enhanced
performance or health

• Athletes have no guarantee of protection from
  heart disease unless they continue prudent habits
  of exercise and diet after their days of
  competition are over.
• Even during heavy training, a diet high in
  saturated fats can raise serum cholesterol to
  high levels.
• Regular endurance exercise will not fully negate
  bad nutritional habits.
• Nearly all studies have shown that high-fat diets
  (about 70 of total energy) for several days
  prior to endurance exercise significantly
  decrease body carbohydrate stores, reducing
  endurance time dramatically. Although the
  relative contribution of fat is increased,
  performance is impaired due to low muscle
  glycogen.

84
Summary

• Refer to page 342 for a summary of the ten
  Principles outlined in the text.