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Sports nutrition 2011


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Sports nutrition 2011

  1. 1. Digestion and Sports Nutrition
  2. 2. The Effects of Good Nutrition <ul><li>Gives you vitality and energy </li></ul><ul><li>Helps you stay at a weight that’s right for you </li></ul><ul><li>Boosts your immune system </li></ul><ul><li>Wards off serious illness such as heart disease, certain types of cancer and Type 2 diabetes </li></ul><ul><li>Delays the effects of aging </li></ul><ul><li>Builds strong, dense bones </li></ul><ul><li>Improves sports performance </li></ul><ul><li>Protects your teeth and keeps gums healthy </li></ul><ul><li>Enhances your ability to concentrate and possibly alter your mood </li></ul>
  3. 3. The Effects of Good Nutrition <ul><li>Many foods benefit the physical health of an individual, as they are known to have specific disease fighting qualities. </li></ul><ul><ul><li>Tomatoes lower the risk of prostate cancer </li></ul></ul><ul><ul><li>Broccoli, cauliflower and brussel sprouts can help reduce the likelihood of contracting cancer </li></ul></ul><ul><ul><li>Fish and seafood help to reduce blood pressure and steady the hearts rhythm </li></ul></ul><ul><ul><li>Tea has been found to lower the risk of contracting cancer and helps keep the heart healthy </li></ul></ul><ul><ul><li>Red wine helps keep the blood thin and allows a smoother flow through the arteries </li></ul></ul>
  4. 4. The Effects of Good Nutrition <ul><li>The Australian Guide to Healthy Eating suggests: </li></ul><ul><ul><li>Eat enough food from each of the five food groups (see the following page) every day </li></ul></ul><ul><ul><li>Choose different varieties of foods from within each of the five food groups from day to day, week to week and at different times of the year </li></ul></ul><ul><ul><li>Eat plenty of plant foods (rice, cereal, bread etc), moderate amounts of animal foods (milk, yoghurt, cheese, etc) and small amounts of the extra foods, and margarine and oils </li></ul></ul><ul><ul><li>Drink plenty of water. </li></ul></ul>
  5. 5. Enjoy a variety of foods every day
  6. 6. Enjoy a variety of foods every day
  7. 7. Nutrients <ul><li>Nutrients are those essential elements in food that we need for life and growth. </li></ul><ul><li>Over 50 types of nutrients are available in the various foods we eat. These different nutrients can be grouped into 7 essential categories: </li></ul><ul><ul><li>Carbohydrates </li></ul></ul><ul><ul><li>Protein </li></ul></ul><ul><ul><li>Fats </li></ul></ul><ul><ul><li>Vitamins </li></ul></ul><ul><ul><li>Minerals </li></ul></ul><ul><ul><li>Dietary fibre </li></ul></ul><ul><ul><li>Water </li></ul></ul><ul><li>Nutrients are required to perform many needs: </li></ul><ul><ul><li>Supply of energy to the body </li></ul></ul><ul><ul><li>Normal growth, development and functioning of the body </li></ul></ul><ul><ul><li>Building, repairing and regulation of the functioning of cells in the body </li></ul></ul><ul><ul><li>Resistance to disease and infection </li></ul></ul>
  8. 8. Carbohydrates <ul><li>Carbohydrates play a vital role in exercise performance because they are the most readily available source of energy to fuel working muscles. </li></ul><ul><li>Digestion breaks down CHO’s into glucose for energy, however if the body does not require it immediately, the glucose is converted to glycogen and stored in the liver and muscles. Any excess of this is then stored as fat. </li></ul><ul><li>CHO’s are broken down from: </li></ul><ul><ul><li>Polysaccharides – starch </li></ul></ul><ul><ul><li>Disaccharides – maltose, sucrose </li></ul></ul><ul><ul><li>Monosaccharides – glucose, fructose, lactose </li></ul></ul>
  9. 9. Carbohydrates <ul><li>CHO’s are divided into two groups: </li></ul><ul><ul><li>Complex carbohydrates (starches) – advantages of these foods are that they take a time to be digested, releasing energy slowly over a long period of time. This provides a constant source of energy to athletes training or competing, reducing their fatigue. </li></ul></ul><ul><ul><ul><li>Examples include; bread, rice, pasta, fruit, legumes, potato, corn and low-fat milk products. </li></ul></ul></ul><ul><ul><li>Simple Carbohydrates (sugars) – these foods are often high in kilojoules and have little nutritional value. However, they are able to release energy instantly because digestion of sugars causes blood glucose levels to rise rapidly. </li></ul></ul><ul><ul><li>This short term response can become a problem for athletes, as the rapidly rising glucose levels result in the release of insulin. Insulin regulates the glucose uptake in the cells, and when it detects such a rise, it informs the cells to not take up anymore. As a result, cell glucose levels fall and the athlete begins to feel hungry and fatigued. </li></ul></ul><ul><ul><ul><li>Examples include; sugar, honey, jam, confectionary, soft drinks. </li></ul></ul></ul><ul><ul><li>Carbohydrates should make up approximately 50 – 60% of your kilojoule intake. From this 40 – 45% should include starches and 15% sugars. </li></ul></ul>
  10. 11. Glycemic Index <ul><li>A ranking system has been created to compare individual carbohydrate foods according to how they affect blood glucose levels. </li></ul><ul><li>This system is called the glycemic index, and it compares blood glucose levels and the rate of carbohydrate digestion. </li></ul><ul><li>Overhead </li></ul><ul><li>‘ Breakdown of Carbohydrates’ </li></ul>
  11. 12. Glycemic Index <ul><li>GI factor questions </li></ul><ul><li>GI factor article </li></ul>
  12. 13. Fats <ul><li>Fats are digested into fatty acids and should make up less than 30% of kilojoule intake </li></ul><ul><li>Fat is an important source of stored energy because it: </li></ul><ul><ul><li>Produces more energy per gram than all other nutrients </li></ul></ul><ul><ul><li>Carries fat soluble vitamins A, D, E and K </li></ul></ul><ul><ul><li>Provides essential fatty acids </li></ul></ul><ul><ul><li>Contributes to the taste, aroma and texture of foods </li></ul></ul><ul><ul><li>Provides protection for certain organs </li></ul></ul><ul><ul><li>Helps to maintain cells and regulates cholesterol </li></ul></ul>
  13. 14. Fats <ul><li>There are two main types: </li></ul><ul><ul><li>Saturated fats – found in animal foods such as milk, cheese, meat and bacon. These fats are known to raise cholesterol levels and should only form 10% of our fat intake. </li></ul></ul><ul><ul><li>Unsaturated fats (monounsaturated and polyunsaturated) – these fats should make up approximately 20% of our fat intake. Sources of poly include; peanut oil, sunflower oils, oily fish like tuna and margarine. Sources of mono include; olive oil, avocado, nuts and canola oil. </li></ul></ul><ul><li>Cholesterol is a fat like substance found in animal products. It is necessary for the body but because the body already produces it, it’s not good to have excess as it settles on the walls of blood vessels and impairs circulation. </li></ul><ul><li>Overhead </li></ul><ul><li>‘ Breakdown of Fats in the Small Intestine’ </li></ul>Intramuscular triglycerides an important fuel source to be discussed later.
  14. 15. Fats
  15. 16. Proteins <ul><li>Proteins are made up of chains of amino acids. There are 20 amino acids that occur in food, and 8 of them are essential to the body. </li></ul><ul><li>Proteins assist in the growth and maintenance and repair of every cell in the body. Assists in the production of enzymes, hormones, red blood cells and antibodies </li></ul><ul><li>It is an emergency fuel source in extreme conditions (starvation, ultra marathons) when carbohydrates and fat stores are depleted. </li></ul><ul><li>Sources of protein include; meat, fish, poultry, eggs, milk, nuts and legumes </li></ul><ul><li>Protein should make up approximately 10 – 20 % of kilojoule intake. </li></ul><ul><li>Overhead </li></ul><ul><li>‘ Breakdown of Proteins’ </li></ul>
  16. 17. Surprising Facts <ul><li>15% of males and 25% of females regularly skip breakfast </li></ul><ul><li>Snacks provide approximately 25% of total energy intake </li></ul><ul><li>Most snacks are high in fat or sugar </li></ul><ul><li>25% of energy intake of Australian adolescents come from sources such as soft drinks, takeaway foods, cakes and biscuits </li></ul><ul><li>40% of males and 47% of females have a calcium intake of less than the recommended daily intake (RDI) </li></ul><ul><li>29% of females have a daily iron intake of less than the RDI </li></ul><ul><li>34% of females and 13% of males diet to lose weight </li></ul><ul><li>(Source: Nutridate, Vol 7 No. 4, September 1996) </li></ul><ul><li> </li></ul>
  17. 18. Vitamins <ul><li>There are 14 vitamins that are classified as A, B group, C, D, E and K </li></ul><ul><li>They regulate the body’s metabolism, speed up the body’s chemical reactions and help with the growth of body tissue </li></ul><ul><li>They are classified into two groups: </li></ul><ul><ul><li>Fat soluble – A, D, E and K are stored in the body </li></ul></ul><ul><ul><li>Water soluble – B group and C, which dissolve in body fluids and excesses are discharged from the body in urine </li></ul></ul>
  18. 19. Vitamins Table 5.7 Vitamins: what they do; where they’re found Vitamin A Functions Improves eyesight Growth in children Healthy skin Resistance to infection Vitamin A Sources Butter and table margarine Oily fish Milk and cream Egg yolk and cheese Vitamin C Functions Healthy gums, teeth and bones Helps tissue repair Assists iron absorption Vitamin C Sources Fruit and vegetables Citrus fruit and juice Capsicum, parsley, broccoli, spinach and cabbage Thiamine (B1) Function Metabolism if CHO Release of energy from food Digestion and appetite Function of heart and nervous system Thiamine (B1) Sources Yeast extract (eg Vegemite) Wheat bran and fortified breakfast cereals Liver, kidney and lean pork Wholemeal flour and bread Vitamin D Functions Strong bones and teeth Absorption of calcium and phosphorus Vitamin D Sources Oily fish Eggs, butter, cheese and table margarine Riboflavin (B2) Function Healthy skin and eyes Release of energy from food Metabolism of CHO, fat and protein Riboflavin (B2) Source Milk, cheese and yoghurt Liver, eggs, almonds and mushrooms Green vegetables Vitamin E Functions Maintains healthy cell membranes Acts as an antioxidant May prevent cancer and heart disorders Vitamin E Sources Vegetable oils and nuts Fruit and vegetables Fish Niacin (B3) Functions Release of energy from food Metabolism from CHO, fat and protein Essential for growth Can be used to lower cholesterol Niacin (B3) Sources Lean meat, liver, tuna and salmon Milk and eggs Fortified breakfast cereals and wheat bran Vegetables Vitamin K Functions Assists blood clotting Vitamin K Sources Green leafy vegetables Eggs and cheese Wholemeal bread and flour
  19. 20. Minerals Table 5.8 Minerals: what they do; where they’re found Needed for: Best food sources: Calcium Hard structure of bones and teeth Prevents rickets and osteoporosis Muscle and nerve functioning Aids blood clotting Milk, cheese and yoghurt Canned salmon and sardines Whole grains, cereals and breads Prawns, broccoli, nuts and milk chocolate Iron Healthy blood; prevents anaemia A key component of haemoglobin A key component of muscle protein Lean, red meat, liver, kidney, chicken and fish Cereals, wholemeal bread and legumes Dark green leafy vegetables Fluorine Healthy bones and teeth Increased resistance to dental caries Possible prevention of osteoporosis Fluoridated drinking water Small amounts in fish Tea Copper Forms a component of enzymes Assists in formation of blood cells Formation of melanin in skin and hair Oysters, crab, lobster and mussels Liver and kidney Nuts, bran and dried fruit Magnesium Provides structure for bones Assists in muscle and nerve function Milk, wholegrain cereals and breads Green leafy vegetables, lean meat Peas, nuts and bananas Potassium Assists transmission of nerve impulses Part of many enzymes systems Counteracts the effects of sodium excess on high blood pressure Nuts, dried fruits and bran Lean meat, fish and raw vegetables Fruit and fruit juice Instant coffee Zinc Healing of wounds and cuts Essential for taste, smell and sight Needed for sexual maturation Provides hard structure of bones Lean meat, liver, kidney and chicken Seafood, especially oysters Whole grains and wholemeal bread Milk and nuts
  20. 21. Water <ul><li>Water is second in importance only to oxygen as a nutrient of the body </li></ul><ul><li>It is the medium for transporting nutrients, removing waste (prevents constipation and aids kidney function), and regulating body temperature </li></ul><ul><li>Water is ingested both from drinking and the food you eat </li></ul><ul><li>More than half your body weight and over 70% of your body mass is water </li></ul><ul><li>Each day the body needs to replace about 2 L of fluid to balance what is lost. You may need up to 9 L a day during more physical activity or while enduring increased temperatures </li></ul><ul><li>Amount of water to be ingested before competition is 400 – 600 mL 30 minutes before the start </li></ul><ul><li>Amount to be ingested during competition is 100 – 200 mL every 10 – 15 minutes throughout the activity </li></ul><ul><li>Following the competition, modest salting of foods and ingestion of drinks with essential minerals will adequately replace electrolytes lost in sweat </li></ul><ul><li>To detect dehydration an athlete should keep a record of their early morning body weight </li></ul><ul><li>Drinks are of significant value in races lasting more than 50 – 60 minutes </li></ul><ul><li>Revision H </li></ul><ul><li>Water or Coke? </li></ul><ul><li>Hydration and Overhydration </li></ul>
  21. 22. Fibre <ul><li>Fibre is the part of the plant that is indigestible </li></ul><ul><li>Fibre is found in cereals, breads, grains, legumes, fruit, vegetables, seeds and nuts </li></ul><ul><li>Fibre helps to ensure a slow release of energy because it slows the release of sugar from the blood, helps us feel full without extra kilojoules, regulates bowel movements and can assist in the maintenance of low blood cholesterol </li></ul><ul><li>There are two types of fibre: </li></ul><ul><ul><li>Soluble – forms a gel that slows absorption and helps lower cholesterol. Sources include; oat bran, apples and oranges </li></ul></ul><ul><ul><li>Insoluble – holds water, increases bulk and eliminates wastes. Sources include; wheat bran and beans </li></ul></ul>
  22. 23. Fibre in Food <ul><li>Dietary food is found in cereals, fruit and vegetables. Fibre is made up of the indigestible parts or compounds of plants, which pass relatively unchanged throughout our stomach and intestines. The main role of fibre is to keep the digestive system healthy. </li></ul><ul><li>Other terms for dietary fibre include ‘bulk’ and ‘roughage’, which can be misleading since some forms of fibre are water soluble and aren’t bulky or rough at all. </li></ul><ul><li>Fibre is a carbohydrate </li></ul><ul><li>Fibre is largely a carbohydrate. The building blocks of all carbohydrates are different types of sugars and they can be classified according to how many sugar molecules are combined in the carbohydrate: </li></ul><ul><ul><li>Simple sugars – consist of 1 – 2 sugar molecules; for example fructose, sucrose, maltose and lactose </li></ul></ul><ul><ul><li>Oligosaccharides – consists of 3 – 10 glucose molecules joined together </li></ul></ul><ul><ul><li>Starch polysaccharides – have more than 10 glucose molecules joined together </li></ul></ul><ul><ul><li>Non-starch polysaccharides – have more than 10 sugar molecules, for example xylose, arabinose and mannose </li></ul></ul>
  23. 24. Fibre <ul><li>Fibre keeps the digestive system healthy </li></ul><ul><li>Dietary fibre is mainly needed to keep the digestive system healthy. It also contributes to other processes, such as stabilising glucose and cholesterol levels. In countries with traditionally high fibre diets, diseases such as bowel cancer, diabetes and coronary heart disease are much less common than in the West. </li></ul><ul><li>Most Australians don’t consume enough fibre. On average, most Australians consume 18 – 25g of fibre daily. The Australian Heart Foundation recommends that adults should consume approximately 30g daily. Australian experts suggest that children should eat 10g of fibre a day plus an additional gram for every year of age. For instance a ten year old should eat 15 – 20g of fibre per day. </li></ul><ul><li>Disorders that can arise from a low fibre diet include: </li></ul><ul><ul><li>Constipation </li></ul></ul><ul><ul><li>Irritable bowel syndrome </li></ul></ul><ul><ul><li>Diverticulitis </li></ul></ul><ul><ul><li>Heart disease </li></ul></ul><ul><ul><li>Some cancers </li></ul></ul>Inulin (type of fibre) in dietary food / meal replacements
  24. 25. Fibre <ul><li>Fibre keeps the digestive tract healthy </li></ul><ul><li>The principle advantage of a diet high in fibre is the health of the digestive system. The digestive system is lined with muscles that massage food along the tract from the moment a mouthful is swallowed until the eventual waste is passed out the bowel (a process called peristalsis). Since fibre is relatively indigestible, it adds bulk to the faeces. </li></ul><ul><li>Soluble fibre soaks up the water like a sponge, which helps to plump out the faeces and allows it to pass through the gut more easily (without aggressive abrasion) . It acts to slow down the rate of digestion . This slowing down effect is usually overridden by insoluble fibre , which doesn’t absorb water and speeds up the time that food passes through the gut. </li></ul><ul><li>Fibre and ageing </li></ul><ul><li>Fibre is even more important in older people. The digestive system slows down with age, so a high fibre diet becomes even more important. </li></ul>
  25. 26. Fibre <ul><li>Lowering blood cholesterol </li></ul><ul><li>Recently, there has been a great deal of interest in oat bran, since some studies showed that regular intake of foods high in soluble fibre – such as oat bran, baked beans and soybeans – reduced blood cholesterol levels. When blood cholesterol levels are high, fatty streaks and plaques are deposited along the walls of arteries (inside the lining under the mucosa) . This can make them dangerously narrow and lead to an increased risk of coronary heart disease. </li></ul><ul><li>It is thought that soluble fibre lowers blood cholesterol by binding bile acids (which are made from cholesterol to digest dietary fats ) and then excreting them. Cereal fibre seems to be more protective against coronary heart disease than the fibre from fruit and vegetables. </li></ul><ul><li>Ways to increase your fibre intake </li></ul><ul><li>Simple suggestions for increasing your daily intake include: </li></ul><ul><ul><li>Eat breakfast cereals that contain barley, wheat or oats </li></ul></ul><ul><ul><li>Switch to wholemeal or multigrain breads and brown rice </li></ul></ul><ul><ul><li>Add an extra vegetable to every evening meal </li></ul></ul><ul><ul><li>Snack on fruit, dried fruit, nuts or wholemeal crackers </li></ul></ul><ul><li>A daily intake of more than 30g can be easily achieved if you eat wholegrain cereal products, more fruit, vegetables and legumes and, instead of low fibre cakes and biscuits, have nuts or seeds as a snack or use in meals. </li></ul><ul><li>You don’t need to eat a lot more kilojoules to increase your fibre intake; you can easily double your fibre intake without increasing your kilojoules intake by being more selective – compare the tables below: </li></ul>Volume increases stretch which aids in peristalsis and prevents dehydration
  26. 27. Fibre intake of less than 20g per day Fibre intake of more than 30g per day Fibre (g) Kilojoules (kJ) Fibre (g) Kilojoules (kJ) 1 cup puffed rice cereal 0.4 444 2 wholewheat cereal biscuits eg weetbix or Vita brits 3.2 398 4 slices white bread 3.0 1166 4 slices wholegrain bread 5.7 1085 1 tablespoon peanut butter 2.7 610 1 tablespoon peanut butter 2.7 610 1 piece of fruit (apple) 1.7 268 2 pieces of fruit (apple and pear) 4.9 515 ½ cup canned fruit, undrained 1.4 468 ½ cup frozen mixed vegetables 4.3 102 1 cup mixed frozen vegetables 8.6 203 Mashed potato 120g 1.7 336 1 small boiled potato with skin 100g 2.8 338 1 cup white rice cooked 1.0 999 1 cup white cooked spaghetti 2.5 696 2 plain dry biscuits 0.4 150 2 wholemeal dry biscuits 1.5 209 1 slice plain cake 60g 0.6 643 25 almonds 3.0 852 1 cup commercial fruit juice 0.8 391 1 cup whole fruit juice 0.5 362 TOTAL 17.9 5,557 TOTAL 35.4 5,118
  27. 28. Energy Balance <ul><li>A grossly unbalanced diet imposes hardships on the body. If energy is too low or it too little carbohydrates or proteins is supplied, the body must degrade its own lean tissue to meet its glucose and protein needs. If energy intake is too high or if fat is abundant, the body stores fat. </li></ul><ul><li>Overweight and underweight both result from unbalance energy budgets. The simple picture is as follows. Overweight people have consumed more food energy than they have spent and have banked the surplus in their body fat. To reduce body fat, they need to spend more energy than they take in from food. In contrast, underweight people have consumed too little food energy to support their bodies activities and so have depleted their bodies fat stores and possible some of their lean tissue as well. To gain weight, they need to take in more food energy than they expend. </li></ul>Not only how many kJ but how fast they enter the system ie swamp the blood - converted
  28. 29. Energy in, Energy out <ul><li>People spend energy continuously and eat periodically to refuel. Ideally, their energy intake covers their energy expenditures without too much excess. Excess energy is stored as fat, and stored fat is used for energy between meals. The amount of body fat a person deposits, or withdraws from, ‘storage’ on any given day depends on the energy balance for that day – the amount consumed (energy in) versus the amount expended (energy out). When a person is maintaining weight, energy in equals energy out. </li></ul><ul><li>Most people maintain a steady energy balance over time. On any given day, they may eat a little more or a little less than usual, and their weight may go up or down a kilo, but for the most part, they stay in balance. When the balance shifts, their weight changes. </li></ul>
  29. 30. Sensible weight loss <ul><li>The Dietary Guidelines suggest a reasonable rate of weight loss for overweight people of ½ to 1kg a week; many obesity experts agree that weight loss should not exceed an average of 1 ½ kgs a week. Even for obese people, a reasonable weight loss rate is only 1% of body weight per week. Such gradual weight losses are more likely to be maintained than rapid losses and can be achieved with a reasonable energy intake of about 10kcalories per pound of body weight. If food energy is restricted too severely, dieters lose lean tissue and may not receive enough nutrients. In addition restrictive eating may set in motion the unhealthy cycle of restrictive dieting and binge eating. </li></ul><ul><li>Quick changes in weight are not just changes in fat. Weight gained or lost rapidly includes some fat, large amounts of fluid and some lean tissues such as muscles and bone minerals. (Because water constitutes about 60% of an adult’s body weight, retention or loss of water influences body weight). Even over the long term, the composition of weight gained or lost is normally about 75% fat and 25% lean. During starvation losses of fat and lean are about equal. Invariably, though, fat gains and losses are gradual. </li></ul>
  30. 31. In summary <ul><li>When the energy consumed equals the energy expended, the person is in energy balance and body weight is stable. If more energy is taken than is expended, the person gains weight. If more energy is spent than is taken in, the person loses weight. </li></ul>
  31. 32. Positive Energy Balance
  32. 33. Neutral Energy Balance
  33. 34. Negative Energy Balance
  34. 35. Energy Balance
  35. 36. Estimating Energy Requirements <ul><li>Energy requirements are determined by a range of functions including you’re: </li></ul><ul><ul><li>Basal Metabolic Rate (BMR) </li></ul></ul><ul><ul><li>Level of activity </li></ul></ul>
  36. 37. BMR <ul><li>The minimum amount of energy you need to carry out the essential processes when the body is at rest is known as BMR. </li></ul><ul><li>BMR differs between males and females. Males generally burn approximately 4.2 kilojoules per hour, whereas females burn approximately 3.8 kilojoules per hour. </li></ul><ul><li>BMR is calculated as follows: </li></ul>Male Female BMR = Weight x 24 hours x 4.2 BMR = Weight x 24 hours x 3.8 For example: For example: BMR for an 80kg male would be: BMR for an 58kg female would be: BMR = 80 x 24 x 4.2 BMR = 58 x 24 x 3.8 = 8064 = 5289.6
  37. 38. BMR <ul><li>A number of factors influence BMR including: </li></ul><ul><ul><li>Age – BMR decreases with age because your body requires more energy for growth when you are young </li></ul></ul><ul><ul><li>Gender – females have a lower BMR because of their higher levels of adipose tissue </li></ul></ul><ul><ul><li>Body composition – the greater the muscle content, the higher the BMR as muscle tissue requires more energy than fat to function </li></ul></ul><ul><ul><li>Temperature – Cold weather increases the BMR because the body needs to produce more heat to keep the body temperature at 37°C </li></ul></ul><ul><ul><li>Build – a bigger person has a higher BMR than a smaller person because they have a larger surface area from which heat is lost. Therefore a bigger person needs more energy to maintain a constant body temperature </li></ul></ul><ul><ul><li>Exercise – regular exercise increases BMR because of the increased energy demand. Inactivity decreases BMR because of the reduced demand for energy </li></ul></ul><ul><ul><li>Diet – a diet which reduces the intake of food unaccompanied by exercise will reduce the BMR </li></ul></ul><ul><ul><li>Fever – a fever will increase BR because of the increase in body temperature </li></ul></ul>
  38. 39. <ul><li>Vini Sample Diet </li></ul><ul><li>Calorie Counter Example </li></ul><ul><li>Energy Balance Activity </li></ul>
  39. 40. Body Weight <ul><li>Body weight is an inaccurate measure of body fat. When assessing an individual’s weight you need to remember that muscle tissue is heavier than body fat. </li></ul><ul><li>It is far more important to measure the ratio between muscle tissue and body fat rather than total body weight. </li></ul><ul><li>There are three main indicators of body fat: </li></ul><ul><ul><li>Weight for height </li></ul></ul><ul><ul><li>Body Mass Index (BMI) </li></ul></ul><ul><ul><li>Skinfold measurements </li></ul></ul><ul><li>Weight for height is the most common method of measuring your total body mass. </li></ul><ul><li>To find out if you are tall enough to carry your weight grab a tape measure and set of scales. </li></ul><ul><li>Take off your shoes and measure how tall you are from the soles of your feet to the top of your head. </li></ul><ul><li>Now plot your position on the graph below which indicates the healthy weight range for various heights by: </li></ul><ul><li>Drawing a line up from your height </li></ul><ul><li>Drawing a line across from your weight </li></ul><ul><li>The point where the two lines intersect (meet) indicates where you fall in relation to the healthy weight range. </li></ul>
  40. 41. Height - Weight table
  41. 42. Height to Weight <ul><li>It must be noted that values are based on average weight samples of the population so may not be suitable for every individual person. Weight can include water, bone, muscle and fat. Athletes for example have a higher percentage of muscle than the average population and muscle weighs more than fat so they would be classed as overweight when in fact they are not fat. Other tests such as the skin fold test can be used to measure fatness. An acceptable body fat percentage for males is 13-15% and 20-25% for females. </li></ul><ul><li>A weight for height measurement does not give an indication of the ratio of body fat to muscle tissue. </li></ul><ul><li>Assessing if an individuals weight is healthy is difficult as they may fall outside of the desirable range as a result of the amount of muscle tissue rather than body fat. </li></ul>
  42. 43. BMI <ul><li>Body Mass Index (BMI) is a more accurate indicator of body fat than using the height to weight measurements. </li></ul><ul><li>To calculate your BMI divide your weight (in kgs) by your height (in m²) </li></ul><ul><ul><li>BMI is calculated as follows: </li></ul></ul><ul><ul><li>BMI = Weight (kg) </li></ul></ul><ul><ul><li>Height (m²) </li></ul></ul><ul><ul><li>For example: </li></ul></ul><ul><ul><li>The BMI for a person 55kg and 170cm would be – </li></ul></ul><ul><ul><li>BMI = 55 = 55 </li></ul></ul><ul><ul><li>1.7² 2.89 </li></ul></ul><ul><ul><li>BMI = 19.03 </li></ul></ul><ul><ul><li>BMI = 19 </li></ul></ul><ul><ul><li>Once you calculate the BMI you need to determine the weight range using the following table which indicates the desirable BMI range for males and females. </li></ul></ul>
  43. 44. BMI tables Weight range Male Female Underweight Up to 20.0 Up to 18.6 Normal 20.1 – 25.0 18.6 – 23.6 Overweight 25.1 – 29.9 23.7 – 28.5 Obese 30.0 and over 28.6 and over
  44. 45. BMI tables
  45. 46. Performance Meals Period Dietary characteristics Before <ul><li>The diet should contain sufficient carbohydrates, as well as vitamins, particularly C, B and E. </li></ul><ul><li>Foods which cause gases should be avoided. Instead foods which promote elimination should be consumed (eg wholemeal bread and fruit) </li></ul><ul><li>Because fats and protein (meats) are digested slowly they should be eaten no less than 3 – 4 hours before activity </li></ul><ul><li>Liquids to hydrate can be taken until 30 minutes before an activity without a negative effect (eg water or fluids with glucose and electrolytes) </li></ul><ul><li>It’s important to remember that a full stomach will divert circulation to abdominal area due to digestion. This will compete with the effectiveness of performance. </li></ul><ul><li>The last main meal should not take place within less than 2 – 3 hours before the activity or competition because of digestion. This meal should, in summary have the following characteristics </li></ul><ul><ul><li>It should be high in carbohydrates </li></ul></ul><ul><ul><li>It should be low in sugar (because it lowers the sugar level and may effect performance) </li></ul></ul><ul><ul><li>It should be low in fat and protein (because they are not easily digestible) </li></ul></ul><ul><ul><li>It should be high in fluids (water is the best) </li></ul></ul>During <ul><li>Rehydration is the main priority, due to fluid loss through perspiration, in particular as the duration of the activity increases, in environments of high temperatures, humidify and stress – fluids should be taken in small quantities, at regular intervals. </li></ul><ul><li>Substitute glucose and electrolytes should also take priority and this can be best done through fluid intake </li></ul><ul><li>It’s important to keep in mind that it’s not possible to take in liquids as fast as we lose them. This, once more, emphasises the importance of fluid intake during exercise </li></ul>After <ul><li>the objective at this stage is to replace water, carbohydrates, vitamins, minerals, fats and proteins </li></ul><ul><li>Liquids and liquid nutrients can be taken soon after effort. However, a big normal meal should only be taken approximately one hour after the event so that digestion wont compete with the cooling down of the body and the necessary muscular circulation to retrieve and eliminate toxins accumulated during effort </li></ul><ul><li>This first main meal should have a high carbohydrate content to replace the depleted glycogen stores </li></ul><ul><li>NOTE: as a general rule during rehydration, we can say that for every kilogram of body weight lost during exercise (through perspiration) you should drink approximately one litre of water. </li></ul>
  46. 47. <ul><li>Carbohydrate Loading Article </li></ul>
  47. 48. Percentage of each food group ingested for an ideal diet for certain sports <ul><li>Source: Frank G. Addleman, The Winning Edge , Simon and Schuster, 1984. </li></ul>Sport Examples Carbohydrates (%) Protein (%) Fat (%) Low duration High intensity Weight lifting Sprinting Jumping and throwing events Moderate duration High intensity Swimming Gymnastics Basketball Rugby Soccer Endurance Marathons Triathlons Cross country running and skiing
  48. 49. Recommended Dietary Intakes (RDI’s) <ul><li>Recommended Dietary Intakes (RDI’s) are the suggested amounts of each nutrient that the individual should consume per day. RDI’s were developed by the Nutritional Health and Medical Research Council (NHMRC). </li></ul><ul><li>RDI’s are the average amount of nutrients that an individual requires in order to function efficiently. If the RDI’s are not met, malnutrition may occur. This can result from an insufficient supply of any nutrients. </li></ul><ul><li>The individual’s need for each nutrient will vary according to their age, gender, genetic make up, metabolic rate and level of activity. </li></ul>
  49. 50. RDI’s for Individual Groups <ul><li>Source: National Health and Medical Research Council (NHMRC), </li></ul><ul><li>Recommended Dietary Intakes for Use in Australia </li></ul>Subject Age (Years) Body Weight (kgs) Energy (kJ’s) Protein (g) Vit C (mg) Vit D (mg) Sodium Iron Zinc Men 18-35 35-55 55-75 70 11600 10400 8800 70 30 - 920-2300 10 12-16 Women Pregnant Lactating 18-35 35-55 55-75 18-35 35+ 18-35 35+ 58 +12 58 8400 7600 6400 9000 8200 10900 10100 58 (+8) 66 (+20) 78 30 60 60 - - - 920-2300 12 15 15 12-16 16-20 18-22 Infants 0.5-1 - 460-420/kg 2.5/kg 30 10 320-580 4.8 4.5-6 Children 1-3 13 5400 20-39 30 10 320-1150 5 4.5-6 Boys 3-7 7-11 11-15 15-18 19 28 41 61 7200 9200 12200 12600 26-51 37-66 51-87 67-90 30 30 30 30 - - - - 460-1730 600-2300 920-2300 920-2300 7 10 12 12 6-9 9-14 12-18 12-18 Girls 3-7 7-11 11-15 15-18 18 27 42 55 7200 8800 10400 9200 2-51 36-61 52-75 60-66 30 30 30 30 - - - - 460-1730 600-2300 920-2300 920-2300 7 10 12 12 6-9 9-14 12-18 12-18
  50. 51. <ul><li>Revision I </li></ul>