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Transcript
Chapter 5: Nutritional Considerations http://www.hulu.com/watch/37290/king-of-the-hill-nutrition-counseling What do you think of when you hear the word nutrition? What do think of when you hear the work diet? Nutrition is the science of the substances that are found in food that are essential to life; Science of certain food substances (nutrients) and what they do in the body Diet refers to your normal eating habits Fact or Fiction Athletes who practice proper nutrition can positively contribute to: Strength Flexibility Cardiorespiratory Endurance Reduction in injuries by maintaining a higher standard of healthful living Unfortunately misconceptions, fads, and superstitions regarding nutrition affect dietary habits in the athletic population Performance vs. Food consumption Surrounded by myths and habits Psychological (I’m playing well) vs. physiological considerations (what it’s doing to your body) An athlete performing well may be reluctant to change what they are eating, thinking it is part of the reason they are playing well when in fact they may be hindering performance The athletic trainer serves as an informational resource regarding nutrition Nutrition Basics Nutrition- Science of substances found in food that are essential to life; Science of certain food substances (nutrients) and what they do in the body What is an essential nutrient? A substance is essential if it must be supplied by the diet Definitions Nutrient Dense Foods: Supply adequate amounts of vitamins and minerals in relation to caloric value Junk Foods: Provide excessive calories from fat and sugar in relation to vitamins and minerals- not nutrient dense Problem- Many people live on junk foods that displace more nutrient-dense foods from there diets Six classes of nutrients: Carbohydrates (CHO) Protein Fat Vitamins Minerals Water Nutrition Basics Science of substances found in food that are essential to life Carbohydrates (CHO) Protein Fat Macronutrients (food sources) Vitamins Minerals Water Micronutrients (regulate body function) Nutritional Considerations Science of substances found in food that are essential to life; Science of certain food substances (nutrients) and what they do in the body Nutrients Carbohydrates Protein Fat Vitamins Minerals Water Roles of Nutrients Growth, repair & tissue maintenance Regulation of body processes Production of energy Energy Sources Carbohydrate Body’s most efficient & primary energy source Accounts for 55-60% (70% for endurance) of total caloric intake Carbs classified as Simple (sugars) and complex (starch and fiber) Simple (sugars) Contain refined sugars with fewer essential vitamins and minerals (honey, yogurt, fruit juice) Digested quickly; cause increase in blood sugar Complex (starches & fiber) Require longer to digest and are typically packed with fiber and other micronutrients (bread, cereals, vegetables, whole grains) Complex carbohydrates should make up the bulk of an athlete’s carbohydrate intake Simple carbohydrate intake should consist primarily of fruits, yogurt or milk Foods high in refined sugar are typically low in nutrients Fats Most concentrated source of energy- 2x the calories as carbs or protein Functions Serves to make food favorable and contain fat soluble vitamins Essential for normal growth and development Cushions organs Saturated vs. unsaturated Saturated (fatty acids derived from animal products; solid at room temperature) Unsaturated (plant derivatives liquid at room temperature) Fat represents a high percentage of the total caloric intake by Americans A substantial amount is from saturated fatty acids (primarily from animal sources) and from trans fatty acids (found in cookies, dairy products, meats and fast foods) High fat intake is believed to contribute to the prevalence of obesity, certain cancers, coronary artery disease Should represent <25% of total calorie intake Trans Fat Trans Fatty Acids Physical properties resembling saturated fatty acids Found in cookies, crackers, dairy and meat products, fast foods Increase levels of bad cholesterol and risk of heart disease No safe level People should eat as little of them as possible Proteins Make up the major structural components of the body Required for growth, maintenance, and repair of the body Aid with enzyme, hormone, and enzyme production Should encompass 12-15% (15-20%) of daily caloric intake Amino Acids Basic units that make up protein 20 amino acids compose the majority of body protein Most can be produced by the body (non essential) while others (essential) must be consumed Animal products contain all essential amino acids Incomplete sources (i.e. plants sources) do not contain all essential amino acids Legumes and beans are a potential source of protein for vegetarians Protein sources and needs Most diets are rich in protein and often athletes consume twice the amount that is recommended Excess protein is converted to fat and may result in dehydration and potential kidney damage Increased physical activity results in increased need for protein in the diet but does not mean you need a protein supplement Increases in muscle mass that occur through training only require small increase in protein Try to obtain protein through your diet. Need approx .6-.9 grams per pound of body weight Production of Energy From Food Energy is produced when cells breakdown CHO, fat or protein to release energy stored in compounds REGULATOR NUTRIENTS Vitamins Vitamins (13) serve as regulators in many body processes Required in only small amounts Fat soluble Vitamins A, D, E , K Found in fatty portion of foods and oils Stored in body fat Possible to consume to much b/c they are stored Water soluble Vitamin C, B-complex vitamins Help to regulate metabolism but cannot be stored; should be consumed daily Each serves a series of roles Excess is secreted in urine Vitamins Anitoxidants May prevent premature aging, cancers, heart disease and other health problems Help protect cells from free radicals Include vitamins A, C, E Found in a number of dark green, deep yellow and orange fruits and vegetables Overdose Consuming to much of a vitamin can cause toxicity (especially C and E). Vitamin Deficiencies Illness that results from a deficiency in a particular vitamin/mineral Are avoidable if an adequate diet is consumed Minerals More than 20 minerals have essential roles in the body Eating a wide variety of foods will insure adequate levels Many are stored in liver and bones Examples Iron (energy metabolism and oxygen transport) Magnesium (energy supplying reactions) Calcium (bone/teeth formation, clotting, muscle contractions) Sodium and Potassium (nerve conduction) Examples: magnesium, sodium, potassium, iron, calcium, copper, zinc, iodine, fluorine, and phosphorus Water Most essential nutrient and most abundant in body (60% of body weightvaries +/- 10% due to age and % body fat) Should be of greatest concern to the athlete Essential for all chemical processes Lack of water (dehydration) can lead to illness and death 1-2% lose in body weight triggers thirst. If not replenished dehydration occurs and energy levels decline Body has mechanisms to maintain homeostatic levels of hydration H2O Adequate water intake is necessary for: Energy production in all cells Assists w/digestion and maintains proper environment inside and outside cells Temperature regulation Elimination of waste products of nutrient and body metabolism Remember, thirst is not an indicator of hydration Average adult requires a minimum of 2.5 liters or about 10 glasses of water a day Athletes require more Hydration Before exercise - Hydration should begin at least two hours before exercise with 17 to 20 oz. of water or sports drink, followed by 7 to 10 oz. 10 to 20 minutes before exercise. During exercise - Consume 7 to 10 oz. of water or sports drink every 15 to 20 minutes. After exercise - Approximately 20 to 24 oz. of water or sports drink should be consumed per pound of body weight lost during the course, until two hours after exercise has finished. Electrolytes Sodium, chloride, potassium, magnesium, and calcium are electrically charged ions dissolved in body water Keep amount of water in your body in balance Electrolyte Requirements Involve minerals of the body - must maintain adequate levels for optimal functioning Excess sweating can lead to depletion of these electrolytes Help to maintain levels of hydration Can generally be maintained through proper diet, however, additional salts may need to be added periodically When Do I Need a Gatorade? Electrolytes need to be replenished if a person is not fit, sweats excessively, and after intense or prolonged periods of exercise Electrolyte loss can produce muscle cramping and heat intolerance Nutrient Requirements and Recommendations MyPlate Newly introduced in 2011 Government's primary food group symbol designed to help consumers adopt healthy eating habits Consistent with the 2010 Dietary Guidelines for Americans Emphasis on fruits, vegetables, grains, protein and dairy food groups MyPlate illustrates the five food groups using a familiar mealtime visual- a place setting http://www.drexel.edu/nutritioneducation/Website_Materials/FY2012%20Lesson%20Materials/HS/Lessons/HS%20MyPlate%20re v%207%2029%2011.pdf www.Choosemyplate.gov Provides practical information to help consumers build healthier diets. Tools for dietary assessment, nutrition education, and other userfriendly nutrition information Goal is that online resources will empower people to make healthier food choices MyPlate Message.. Balancing Calories Enjoy your food, but eat less. Avoid oversized portions. Foods to Increase Make half your plate fruits & vegetables. Make at least half your grains whole. Switch to low-fat (1%) or fat-free (skim) milk. Foods to Reduce Choose foods that have less sodium. Drink water instead of sugary drinks. Build A Healthy Plate By Choosing… • Nutrient-dense foods • • • • instead of calorie-dense foods. A variety of fruits and vegetables in a rainbow of colors. Low-fat or fat free milk and dairy products. Fiber-rich whole grains. Protein foods that are low in fat. Cut Back On… • SOLID FATS – Saturated fat & trans fat heart disease – Replace with healthy unsaturated fat • ADDED SUGAR – Sugar adds calories weight gain – Choose water, 100% juice and fruit for dessert • SALT (SODIUM) – Raises blood pressure hypertension – Processed foods, fast food, frozen meals – Season with spices and herbs instead of salt Not All Foods Are Created Equal Any-time Sometimes Balance Calories Eat the right amount of calories for you Enjoy your food, but eat less Cut back on foods high in SOFAS and empty calories • Avoid oversized portions • Stop eating when you feel full • Get enough physical activity 2010 Dietary Guidelines Basis of the federal government's nutrition programs Action oriented messages Will help professionals and media to understand and deliver relevant nutrition information Examples Enjoy your food, but eat less Avoid oversized portions Make half your plate fruits and vegetables Drink water instead of sugary drinks Nutrient Dense Food vs. Junk Foods Nutrient dense food Contains considerable amount of vitamins, minerals, and proteins in relation to caloric content Junk foods Cookies, candies, doughnuts, chips Everything in moderation Avoid substituting junk food for nutrient dense foods Supplements Athletes often believe that more is better Activity increases need for energy not necessarily all vitamins, minerals and nutrients No evidence to support ingesting quantities of nutrients above Dietary Reference Intake (DRI) levels Many myths about consumption of dietary supplements in terms of performance enhancement Often a belief that a particular substance will produce an effect when it truly does not Placebo effect = psychological boost Little pre-market approval or post-market surveillance FDA oversee proof of safety or harm of supplements Has only acted with regard to ephedrine Prior to engaging in supplementation the following recommendations should be followed Consult a licensed nutritionist or physician prior to beginning supplementation Coaches should not provide or distribute supplements of any kind May be in violation of state laws or state/national governing bodies (i.e. NCAA) Supplementation Vitamin Supplementation Athletes believe large doses can lead to superior health and performance A mega-dose of a nutrient supplement is essentially an overdose Vitamin requirements do not increase with exercise Excessive fat-soluble vitamin supplementation may be toxic Common practices Vitamin C To prevent common cold and slow aging May cause kidney stones and diarrhea Vitamin E Protects cell membranes from damage Little evidence to support enhancing performance or life expectancy B-complex vitamins Aid in release of energy from CHO, fat, and protein If additional energy is required, increased caloric intake is necessary If an athlete does not eat a well balanced diet, taking a multi vitamin once a day may be helpful Mineral Supplementation Calcium and iron tend to be low and diets may need to be modified Need to be certain additional minerals are necessary in diet prior to purchase (save money) Calcium Deficiency Most abundant mineral in body; essential for bone and teeth, muscle contraction and nerve impulse conduction Females tend not to get enough calcium in diet Over time additional levels of calcium are required for bone maintenance if intake is to low to meet needs Without supplementation, the body can remove calcium from bones creating a condition in which bones become weak and brittle called osteoporosis Young adult requires 1000mg/day (300mg in an 8 oz glass of milk) While exercise helps bones to retain calcium, extreme levels of exercise, causing hormonal imbalances, can disrupt calcium retention Supplementing with calcium carbonate or citrate is advisable Milk products are the most reliable source of calcium Some athletes complain it causes upset stomach due to a build up of intestinal gas May be lactose intolerant and lack the enzyme lactase (lactase deficient) Can supplement with lactase (scientifically produced) Iron Deficiency Iron is needed to properly form hemoglobin (oxygenates blood) Common in females Results iron-deficiency anemia, which reduces the oxygen carrying ability of the red blood cells, so muscles cannot obtain enough oxygen to generate energy. Athlete feels tired and weak due to muscles’ inability to generate energy Critical Thinking A volleyball player complains that she constantly feels tired and lethargic even though she thinks that she is eating well and getting a sufficient amount of sleep. A teammate has suggested that she begin taking vitamin supplement, which, the teammate claims, will give her more energy and make her more resistant to fatigue. The athlete comes to the sports nutritionist to ask advice about what she needs to take. What facts should the sports nutritionist explain to the athlete about vitamin supplementation and what recommendations should be made? Protein Protein Supplementation To build muscle approximately 1-1.5g extra per kg of body weight of protein should be consumed for increasing muscle mass (.5-.7 grams per pound) Often times exceeded with normal diet and supplementation is not necessary Should attempt to meet additional requirements via diet Types: Whey, Egg, Soy Creatine Creatine Supplementation Naturally occurring substance in body produced by kidneys, pancreas and liver Found in meat and fish that contain approx. 5 g/kg Integral role in metabolism Two types (free creatine and phosphocreatine) Phosphocreatine is stored in skeletal muscle and works to re-synthesize ATP during activity Positive effects Increased resynthesis of ATP; allows for increase intensity of workouts lactic acid buffer; prolongs maximal effort and improving exercise recovery time during maximal intensity activities stimulates protein synthesis decreases total cholesterol and total triglycerides and improves HDL-LDL ratio increases fat free mass Negative effects weight gain muscle cramping gastrointestinal disturbances and renal dysfunction Not a banned substance, however, distribution by NCAA institutions is banned No long-term side effects have been found Creatine Dosage 3g/kg body weight for 30 days followed by washing phase Not necessary to do a loading phase Steroids http://www.ebaumsworld.com/video/watch/80793445/ Herbal Supplements Trend - natural alternatives to drugs and medications Little evidence to support use in professional literature Wide spread use in general and athletic populations Discussion is warranted due to the extensive use patterns in society Safe to ingest as natural medicines with few side effects (occasional allergic reaction) Offer nutrients that nourish brain, glands and hormones Don’t need to consume with food Contain own digestive enzymes Work with the body’s functions (whole body balancers) Caution must be exercised as there is no governmental control or regulation Example: Ginseng Ephedrine Stimulant used in diet pills, illegal recreation drugs and legitimate OTC medications Similar to amphetamine FDA has posted warning concerning use Banned as dietary supplement by FDA in 2003 NCAA and minor league baseball have banned use by athletes Potential dangers associated with use include Heart attack, stroke, tachycardia Paranoid psychosis, depression, convulsions, coma Fever, vomiting, palpitations, hypertension Hypertension and respiratory depression Popular Eating and Drinking Practices Caffeine Caffeine Central nervous system stimulant found in carbonated beverages, coffee, tea (chocolate contains compounds related to caffeine) It is a DRUG Increases alertness and decrease fatigue Too much causes nervousness, irritability, increased heart rate and headaches; experience withdrawal when trying to stop Headaches may result when ceasing caffeine use (withdrawal) Not detrimental to performance Enhances fat utilization and endurance performance Makes calcium more available during muscle contraction allowing muscles to work more effectively May cause slight headaches Olympic officials consider caffeine a drug and many not be found in a competitors blood level greater than that resulting from drinking 5-6 cups of coffee Energy Drinks Different than sports drinks Sports drinks contain no caffeine. Energy drinks contain caffeine (or caffine like herb) that can range anywhere from 50 mg to 500 mg Contain high levels of CHO; often carbonated Marketed as performance-enhancers and stimulant drug effects. Multiple risks associate with caffeine intoxication Consumed by 30-50% of people Energy drinks do not provide energy; they are stimulants Sugar free; no calorie; no energy There is currently little government regulation of energy drinks, including content labeling and health warnings. Many contain unregulated herbs and ingredients are not standardized so you may be getting to much=toxicity Some ingredients may cause side effects Most cans contain multiple servings but are consumed in one sitting May cause heart palpitations, increase in BP, dehydrations Alcohol Consumption Provides energy for the body 7 calories per gram of alcohol Little nutritional value Central nervous system depressant Decreases coordination, slows reaction time, decreases mental alertness increases urine production (diuretic effect) Not recommended for use by athletes before, during or after physical activity Organic, Natural, of Health Foods Claim to be safer and nutritionally superior due to absence of pesticides and fertilizers Organic refers to the way farmer grow and process fruits, vegetables, grain, meats, poultry, eggs & dairy Grown w/out synthetic fertilizers or pesticides USDA indicates that organic foods are not more nutritious, safer, or more flavorful Natural foods are subjected to little processing and contain no additives such as preservatives or artificial flavors Processing can protect nutritional value Preservatives save food that would otherwise spoil Many foods in their natural form are poisonous Recommended foods to buy organic Meat, milk, coffee, celery, peaches, strawberries, apples, blueberries, nectarines, peppers, spinach, kale, cherries, potatoes, grapes, leafy greens, carrots, pears, tomatoes Recommended foods not to buy organic Onion, avocados, sweet corn, pineapple, mango, asparagus, sweet peas, kiwi, cabbage, eggplant, papaya, watermelon, broccoli, tomato, sweet potato Organic video: http://today.msnbc.msn.com/id/13737389 Alternative Eating Practices Practicing Vegetarianism Utilize plants to form foundation of diet - animal foods are either excluded or included in a variety of eating patterns Reasons for becoming: economic, philosophical, religious, cultural, or health reasons While practiced intelligently (not a fad) a vegetarian diet can result in deficiencies Diet must be carefully planned Total Vegetarian (vegan) all plant diet, no animal products must be certain to consume enough calories and vitamin B12, calcium, zinc, and iron Lactovegetarian Consume plant foods and milk products Must watch iron and zinc levels Ovolactovegetarian Consume plant foods, milk products and eggs Iron is still a concern Semivegetarian Still primarily plants but all other products are consumed except red meat. Pre-event Nutrition Pre-event Nutrition Avoid superstitions and myths Purpose is to maximize carbs stored in muscle and to provide competitor with sufficient nutrients, energy and fluids for competitions taking digestibility into consideration and the eating preferences of the individual athlete Nutrients consumed over several days before competition are much more important than what is eaten three hours before an event Pre-game meal should be consumed 3-4 hrs before competition. Food takes approx. 4 hrs to digest and often longer due to nervousness which slows digestion Meal should be approx 2/3 (60%) carbs and the rest protein/fat (avoid high fat/fiber foods) Different carbohydrates are digested and absorbed at different rates. Glycemic index (GI) indicates the how much different types of carbohydrate effects blood glucose levels Foods with low to medium GI are recommended prior to an event Produce only small fluctuations in blood glucose and insulin levels Release energy more slowly over a longer time period. Foods selected should minimize gastrointestinal distress Critical to make certain that the athlete is appropriately hydrated. Tips Encourage athletes to be conscious of diet Diets are individual to each athlete Individual is the best judge of what should or should not be consumed What is the individual comfortable with Be sure to practice your nutrition (don’t eat something new before a game w/o trying it first!) Sample menu LUNCH l LUNCH 2 Whole Wheat Bread Vegetable Soup Turkey Breast Meat Crackers and Tomato/ Lettuce Graham Crackers Low-Fat Cottage Cheese Peach or Nectarine Pineapple Water Water LUNCH 3 Spaghetti Tomato Sauce with Mushrooms Green Beans or Carrots French Bread orange Water Post-Event Nutrition Important that athletes replenish glucose stores after activity Recommended that foods high in carbohydrate content be eaten within two hours (bananas, sandwich, sports drink) Should have a high glycemic index Next main meal consumed within several hours should be rich in CHO Restoration of CHO stores may take 24 hrs. Breakfast “Break” the “Fast” Most important meal of the day; should never be skipped! According to webmd.com Students are more likely to be late or tardy if they skip breakfast Skipping breakfast increases weight gain and obesity due to nibbling, eating larger meals later Breakfast eaters have a higher intake of essential vitamins and minerals, lower cholesterol, improved concentration and performance in the classroom, more strength and endurance, and can potentially live longer Liquid Supplementation Nutrition shakes have been recommended as effective pre-event meals Extremely effective and successful Supply 225-400 calories per serving Successful in reducing pre-game symptoms of dry mouth, abdominal & leg cramps, nervous defecation and nausea Food generally takes 4 hours to clear stomach and upper GI tract Advantage is b/c liquid supplements clear stomach and upper bowel before game time, settling the stomach and thus making available the caloric energy that would otherwise still be in an unassimilated state Fast Foods Way of life in America --world of fast food junkies Often meal of choice during travel Big concern is the amount of fat (40-50% of calories from fat) Size vs. supersize Increased menu size is a plus; menus now include better food choices such as salads and fresh fruit and yogurt (variety) Super Size Me: http://www.youtube.com/watch?v=N2diPZOtty0 Look at the nutritional information posting http://www.mcdonalds.com/usa/eat.html http://www.yum.com/nutrition/documents/kfc_nutrition.pdf http://www.yum.com/nutrition/menu.asp?brandID_Abbr=5_TB Low Carbohydrate Diets While fat reduction had been the trend in dieting, new recommendations for CHO reduction have come forth Numerous versions Most replace CHO intake with protein and fat Reasoning: Unused CHO is readily turned into fat CHO consumption increases insulin production Insulin, while allowing cells to use blood glucose, also encourages fat to be deposited and a hunger response to be triggered Tendency is to consume more CHO as a result Hyperinsulinemia It is believed most overweight people suffer hyperinsulinemia, elevated insulin in the blood, which contributes to individuals becoming overweight CHO restriction halts insulin cycle and improves glucagon production, a hormone which enhances fat burning and cholesterol removal from blood vessels Severe CHO restriction results in ketosis, which stabilizes blood glucose, a reduction in insulin levels and rapid weight loss Glycogen Supercompensation Increase muscle and liver glycogen stores prior to major event by altering eating and training habits Increase CHO loading to increase glycogen stores and positively impact muscle glycogen and muscle endurance Six-day period Phase I (Days 1-2): hard training with reduced CHO intake Phase II (Days 3-5): decrease training and increase CHO (potentially increasing glycogen stores 50-100%) Phase III (Days 6-7): resume normal diet Not clearly demonstrated as being beneficial in endurance activities Do not perform more than 2-3 times per year Ideally for prolonged duration events Fat Loading Fat loading vs. carbohydrate loading Intent = better energy source Negative side effects Cardiac protein and potassium depletion Development of arrhythmias, increased serum and cholesterol Weight Control and Body Composition Weight Control and Body Composition Gains and loss of weight in athletes can be problematic Intelligent and conscientious approach involves some knowledge of what is involved on the part of the athlete and athletic trainer Results in athlete displaying discipline relative to types and quantities of food Body Composition Body comp refers to both fat and non-fat components of the body Ideal body weight often determined by age related height and weight charts These charts are sometimes inaccurate due to broad ranges and failure to take individual body types into consideration Health and performance may be best indicators Percent body fat=portion of total body weight composed of fat tissue Lean body weight=total body weight that is composed of nonfat or lean tissue -bone, muscle, tendon, connective tissue Body comp is the relationship between fat tissue and lean body tissue Average % body fat for college age Female 20-25% body fat Male 12-15% body fat Endurance female 10-18% and male 8-12% Should not fall below 3% and 12 % for males and female respectively Results in loss of essential fat padding for organs American Council on Exercise Description Essential fat Athletes Fitness Average Obese Women 10–13% 14–20% 21–24% 25–31% 32%+ Men 2–5% 6–13% 14–17% 18–24% 25%+ Overweight = excess body weight relative to size and stature; can still be healthy Overfat = excessively high percentage of total body weight is fat Obesity = extreme amount of excessive fat Female >30% and male >20% percent body fat Factors that determine amount of body fat Number of fat or adipose cells Proliferation or hyperplagia of fat cells occurs from birth to puberty; levels set by adulthood Size of cells Increase/decrease over time until adulthood relative to caloric balance Change of weight = change in size not number Adipose cell stores triglycerides (liquid fat) Moves in and out of cells according to energy demands Moderate, long term activity uses greatest amount of fat One pound of fat = 3500 calories, stored as triglycerides Determining Body Mass Index Determine extent of overweight or obesity using height and body weight BMI (body mass index) is a ratio of height and weight Utilized to measure health risks associated with obesity BMI Weight Status Below 18.5 Underweight 18.5—24.9 Normal 25.0—29.9 Overweight 30.0 and Above Obese BMI Chart Obesity Statistics http://www.cdc.gov/obesity/data/trends.html Assessing Body Composition Several methods Hydrostatic, bioelectrical impedance, skinfold thickness measures, bod pod Skinfold technique measures the thickness of subcutaneous fat since 50% of body fat is subcutaneous Utilize skin fold calipers Relatively low accuracy but is easy to learn and utilize Error is + 3-5% Technique by Jackson and Pollack measures thigh, triceps, suprailiac, abdominal, and chest Hydrostatic Weighing Utilizes underwater tank to determine body density Establishes relationship between lean mass (more dense) and fat mass (resulting in more buoyancy) Very accurate method Not always available, expensive equipment Time consuming Requires exhaling all air Bioelectrical Impedance Measures resistance of electrical current flow through body between points Based on principle that electricity will flow through path of least resistance Fat is a poor conductor of electrical energy and a good insulator Water/lean tissue is a good conductor Impacted by levels of hydration Expensive equipment .??. Bod Pod Assessing Caloric Balance Change in body weight is result of change in caloric balance Caloric balance = Calories consumed - calories expended Positive caloric balance = weight gain negative caloric balance = weigh loss Can be calculated through accurate record keeping of calories consumed and expended relative to metabolic and activity needs If more calories are consumed that eaten=weight gain If more calories are expended than consumed=weight loss Calories are expended through: basal metabolism (calories expended at rest) = BMR work (activity that requires more energy than sleeping) excretion Must calculate total time engaged in all 3 areas over a 24 hour period BMR is determined in laboratory setting through indirect calorimetry which measures oxygen uptake Work (type, intensity, duration) must be determined Body size also factors in Energy expenditures can be consulted to determine average energy expenditures per activity (kcal/min/lb) Calorie Consumption/Intake Calorie balance is determined by the number of calories consumed regardless of whether the calories are from fat, CHO, or protein CHO=4 calories/g Protein=4 calories/g Fat=9 calories/g Estimations of caloric intake for college athletes=2,0005,000 calories per day Endurance athletes may consume as many as 7000 calories Methods of Weight Loss Weight loss occurs through dieting, increased activity, or combination of the two- diet and exercise Weight loss through exercise or dieting alone is difficult and in most cases ineffective means of weight control over the long run 35-45% of weight loss due to dieting alone results in lean body tissue loss Should not drop below 1000-1200 calories for women and 1200-1400 for men Weight loss through exercise involves an 80-90% loss of fat tissue w/almost no loss of lean tissue Exercising, while resulting in loss of fat mass, will also enhance strength, cardiorespiratory endurance and flexibility The key is moderation Most effective weight loss method is a combination of dieting and exercise A negative energy balance must be achieved Loss of 1.5-2.0 pounds per week is adequate Weight loss of more than 4-5 pounds per week can be attributed to dehydration It takes time to put weight on and also takes time to take it off 3500 calories = 1 pound; must cut or expend 3500 to lose 1 lbs; 500 calories/day = 1 lbs/wk http://www.youtube.com/watch?v=seZU8UBOoYo Diets South Beach Jenny Craig Atkins HCG Paleo Weight Watchers Zone Nutri System Diet Research Questions Name of your diet What is the basic concept of your diet? How/what are you supposed to do to lose weight? What are the associated cost/expenses? How long has the diet been around? Are there medical side effects? What are your thoughts on the effectiveness/safety of the diet? Methods of Weight Gain Aim should be to increase lean body mass Done through increased physical activity (muscle work) and dietary modifications Approximately 2500 calories is required per pound of lean body mass b/c it contains more water and protein than fat An increase 500-1000 calories per day will provide enough energy needs to gain 1-2 lbs/wk A 1-2 pound per week gain is adequate Disordered Eating Disordered Eating Spectrum of abnormal eating habits ranging from mild food restriction, binging, purging, bulimia, anorexia nervosa Multi-factorial disorders include social, familial, physiological, psychological components Screening test are now being used to detect disorders More prevalent in athletic populations Control over body weight/composition for increased performance In addition to the emotional and social pressures characteristic of eating disorders, physiological effects can impact health and performance of the athlete Education of athletic trainers in this area is critical Prevention and management strategies Bulimia Generally females ranging in age from adolescence to middle age 1-2% of population will develop bulimia nervosa, anorexia nervosa or both Typically gorges self w/thousands (bingeing) of calories after periods of starvation and then purging through vomiting, fasting and laxatives/diuretics Characteristics Typically bulimic athletes are white, middle to upper-middle class Perfectionist, obedient, overcompliant, highly motivated, successful academically, wellliked, and a good athlete Commonly participates in gymnastics, track, dance occasionally seen in male gymnasts and wrestlers Bingeing and purging can result in stomach rupture, heart rhythm, liver damage, tooth decay from acids, chronically inflamed mucous lining of mouth and throat Anorexia Nervosa 30-50% of anorexics also suffer from bulimia Characterized by distorted body image and constant concern about weight gain Impacts mostly females Starts often with adolescents and can be life threatening; 15-21% of individuals diagnosed ultimately will die While the athlete tends to be too thin they continue to feel fat Deny hunger and are hyperactive, engage in abnormal amounts of exercise, and are highly secretive Early intervention is critical with eating disorders Empathy is a must Psychological counseling is key Must have athlete recognize the problem, accept the benefits of assistance and must voluntarily accept help for treatment to work Anorexia Athletica Condition specific to athletes Characterized by features common in anorexia nervosa w/o self-starvation practices Signs Disturbance of body image Weight loss >5% of body weight Gastrointestinal complaints Primary amenorrhea Menstrual dysfunction Absence of illness explaining weight reduction Fear of becoming obese Binging, purging, compulsive eating, or caloric restriction Female Athlete Triad Potentially fatal problem Combination of eating disorder, amenorrhea (cessation of menstral cycle) and osteoporosis Some suggest eating disorders may exist in 62% of females in certain sports and amenorrhea found in 60% Major risk is the fact that bone lost may not be regained Herbs Using Herbal Supplements Trend - natural alternatives to drugs and medications Safe to ingest as natural medicines with few side effects (occasional allergic reaction) Offer nutrients that nourish brain, glands and hormones Herbs are not drugs but rather are body balancers that work with the body’s functions so it can heal and regulate itself Do not need to be taken w/food as they provide their own digestive enzymes No federal or governmental controls regulating sales