© 2011 mcgraw-hill higher education. all rights reserved chapter 5: nutrition and supplements

© 2011 McGraw-Hill Higher Education. All rights reserved

Chapter 5: Nutrition and Supplements


• Proper nutrition can positively contribute to:– Strength– Flexibility– Cardiorespiratory Endurance

• Performance vs. Food consumption– Myths and habits vs. physiological benefits– Psychological vs. physiological

considerations• In a clinical, corporate or industrial setting

the ATC may be responsible for providing nutritional counseling

Nutrition Basics

• Science of substances found in food that are essential to life– Carbohydrates (CHO)– Protein– Fat– Vitamins– Minerals– Water

Macronutrients

Micronutrients


Nutritional Considerations

Nutrients• Carbohydrates• Protein• Fat• Vitamins• Minerals• Water

Roles• Growth, repair &

tissue maintenance

• Regulation of body processes

• Production of energy

Science of substances found in food that are essential to life


Carbohydrate• Body’s most efficient energy source• Accounts for 55-60% of total caloric intake• Sugars

– Simple (sugars) and complex (starch and fiber)– Monosaccharides

• single sugars (fruits, syrup and honey)• Glucose

– Disaccharides• 2 sugars combined (milk sugar, table sugar)

– Should account for <15% of caloric intake


• Starches– Complex CHO– Long chain glucose units– Rice, potatoes, breads– Body cannot use starch directly

• Broken down in simple sugars• Unused starches and sugars are stored as

glycogen to be used by the body later• Inadequate CHO intake results in protein

utilization for energy• Protein sparing action of glucose occurs if

adequate CHO in the system


• Fiber– Structural part of plants and is not digestible in

humans– Soluble

• Gums, pectin• Oatmeal, legumes, and some fruits

– Insoluble• Cellulose• Grain breads and bran cereal

– Aids normal elimination of waste (bulk)– Reduces risk of colon cancer and coronary

artery disease– Reduces incidents of obesity, constipation,

colitis, appendicitis, and diabetes© 2011 McGraw-Hill Higher Education. All rights reserved

– Intake should be approximately 25 grams per day

– Most only consume 10-15 grams per day– Excessive consumption may lead to

intestinal discomfort and increased loss of calcium and iron


Fats• Most concentrated source of energy

– Should account for 25-30% of caloric intake• Serves to make food flavorful and

contains fat soluble vitamins• Essential for normal growth and

development• Saturated vs. unsaturated

– Saturated (fatty acids derived from animal products

– Unsaturated (plant derivatives - liquid at room temperature)


• Other Fats– Phospholipids

• Lecithin

– Sterols• Cholesterol (consume <300mg/day)

– Omega-3 fatty acids (unsaturated fat) aids in reduction of heart disease, stroke, hypertension)• Found in cold-water fish

• Fat Substitutes– Simplese and Olean– Contain 80% fewer calories than fat and no

cholesterol– May cause abdominal cramping and diarrhea


• Trans Fatty Acids– Physical properties resembling fatty acids– Found in cookies, crackers, dairy and meat

products, fast foods– Increase levels of bad cholesterol– No safe level– People should eat as little of them as

possible


Proteins

• Required for growth, maintenance, and repair of the body

• Aid with enzyme, hormone, and enzyme production

• Should encompass ~15% of daily caloric intake


• Amino Acids– Basic units that compose protein– 20 amino acids compose the majority of

body protein– Most can be produced by the body 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


• 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


Regulator Nutrients• Vitamins (13) serve as regulators in many

body processes• Fat soluble

– Vitamins A, D, E , K– Found in fatty portion of foods and oils

• Water soluble– Vitamin C, B-complex vitamins– Help to regulate metabolism but cannot be

stored– Each serves a series of roles


• Antioxidants– 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– Supplements

• Vitamin Deficiencies– Illness that results from a deficit in a

particular vitamin/mineral– Are avoidable if an adequate diet is

consumed© 2011 McGraw-Hill Higher Education. All rights reserved

Minerals

• More than 20 minerals have essential roles in the body

• Many are stored in liver and bones• Examples

– Iron (energy metabolism and oxygen transport)

– Magnesium (energy supplying reactions)– Calcium (bone formation, clotting, muscle

contractions)– Sodium and Potassium (nerve conduction)


Water

• Most essential nutrient and most abundant in body (60% of body weight)

• Essential for all chemical processes• Lack of water (dehydration) can lead to

illness and death• Body has mechanisms to maintain

homeostatic levels of hydration (kidneys and solute accumulation)


• 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 maintain through proper

diet, however, additional salts may need to be added periodically


Nutrient Requirements and Recommendations

• Amount of nutrient required to prevent deficiency diseases

• Vary among individuals and across populations

• Requirements vs. Recommendations– RDA (Recommended Daily Allowance) vs.

DRI (Dietary Reference Intake)


• DRI includes:– RDA– UL’s (upper intake levels)– EAR (estimated average requirements)– AI (adequate intake)

• Food Labels– Aids consumers in determining levels of

nutrients in foods


Figure 5-2


MyPyramid

• Replaced Food Guide Pyramid in 2005• Emphasizes more individualized

approach for diet and lifestyle– Stresses benefits of improvements in

nutrition, lifestyle behavior and physical activity

• Identifies amounts of food to consume depending on energy expenditure


• Represents recommended proportions of every food group while focusing on the importance of making smart food choices daily

• MyPyramid Symbol illustrates– Gradual improvement– Physical activity– Variety– Moderation– Proportionality– Personalization


Dietary Supplements• Activity increases need for energy not

necessarily all vitamins, minerals and nutrients

• Vitamin Supplementation– Athletes believe large doses can lead to

superior health and performance– Common megadose practices

• Vitamin C– For prevention of common cold and to 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

• Mineral Supplementation– Calcium and iron tend to be low and diets

may need to be modified• Particularly in those that do not consume dairy

products, red meat or enriched breads/cereals


• Calcium Supplements– Most abundant mineral in body– Over time additional levels of calcium are

required for bone maintenance • Without, bones become weak and brittle resulting in

osteoporosis

– Young adult requires 1000mg/day– Females tend not to get enough calcium in diet– 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 Supplements– Common in females – Results iron-deficiency anemia, limiting oxygen

carrying capacity of blood• Athlete feels tired and weak due to muscles’ inability to

generate energy

– Excess supplementation could be toxic and may

result in constipation


• Protein Supplementation– Approximately 1-1.5g/kg body weight of

protein should be consumed for increasing muscle mass

– Often times exceeded with normal diet and supplementation is not necessary

• Creatine Supplementation– Naturally occurring substance in body

produced by kidneys, pancreas and liver– Found in meat and fish– Role in metabolism– Two types (free creatine and

phosphocreatine)© 2011 McGraw-Hill Higher Education. All rights reserved

– Phosphocreatine is stored in skeletal muscle and works to re-synthesize ATP during activity

– Positive effects• increase intensity of workouts• lactic acid buffer• 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


• Loading Phase• Consists of ingesting .3 grams of creatine/kg of body

weight per day• Should be split over 4-5 times per day with 16

ounces of water per dose• Loading phase last for 5 days• Research has shown that loading is not always

required

– Maintenance• Consuming .03 grams/kg body weight for one month

– Wash-out phase• No supplementation for 1 month

• Creatine is not a banned substance, however, distribution by NCAA institutions is banned


• 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

– 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© 2011 McGraw-Hill Higher Education. All rights reserved

• Ephedrine – Stimulant used in diet pills, illegal recreation

drugs and legitimate OTC medications– Similar to amphetamine– FDA has posted warning concerning use; 2003

its use in supplements was banned– NCAA, NFL, NBA, minor league baseball and

the USOC have banned use by athletes– Potential dangers associated with use and has

been known to cause numerous problems• Heart attack, stroke, tachycardia• Paranoid psychosis, depression, convulsions, coma• Fever, vomiting, palpitations, hypertension• Hypertension and respiratory depression


• Glucose Supplements– Ingesting large quantities of sugar prior to

activity causes an increase glucose in the blood

– Release of insulin stimulated, allowing cells to utilize free circulating glucose, sparing blood glucose

– Positive effect on performance– However, some athletes are sensitive to high

CHO feedings and have problems with increased levels of insulin • May lead to upset stomach or diarrhea• Athletes should test themselves with various food

combinations prior to competitive events© 2011 McGraw-Hill Higher Education. All rights reserved

• Caffeine– Central nervous system stimulant found in

carbonated beverages, coffee, tea (chocolate contains compounds related to caffeine)

– Increase alertness and decrease fatigue– Not detrimental to performance

• Enhances fat utilization and endurance performance

• Makes calcium more available allowing muscles to work more effectively

• May cause slight headaches

Popular Eating and Drinking Practices


• Caffeine (cont.)– Too much causes nervousness, irritability,

increased heart rate and headaches– Headaches may result when ceasing caffeine

use (withdrawal)– Olympic officials consider it to be a drug

• Should not be present in a drug test at levels greater than 5-6 cups of coffee

– Energy Drinks• Contain high levels of caffeine• Also contains some legal herbal supplements• Use may result in increased HR, BP, dehydrate

the body and interfere with sleep• Should not be combined with exercise as fluid

loss from exercise and diuretic quality of caffeine can result in severe dehydration


• Alcohol– Provides energy for the body– Little nutritional value– Central nervous system depressant

• decreases coordination, slows reaction time, decreases mental alertness

• increases urine production (diuretic effect)– Alcohol consumption is not recommended before,

during or after activity


• Organic, Natural, of Health Foods– Claim to be safer and nutritionally

superior due to absence of pesticides and fertilizers

– All foods are organic due to presence of carbon

– More expensive no increased benefit physiologically

– Processing (preservatives) helps to maintain nutritional value


Vegetarianism

• Utilize plants to form foundation of diet - animal foods are either excluded or included in a variety of eating patterns

• 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

• Importance and content pre-event meal vs. traditional rewarding that may hamper performance– Traditional steak and eggs

• Long term food consumption is more important than immediate consumption

• Purpose should be to provide competitor with nutrients/energy and fluids for competitions (taking digestibility into consideration


• Encourage athletes to be conscious of diet• Diets are also individual to each athlete• Individual is the best judge of what should

or should not be consumed• What is the individual comfortable with• Liquid Supplementation

– Extremely effective and successful– 225-400 calories per serving– Successful in reducing pregame symptoms of

dry mouth, abdominal & leg cramps, nervous defecation and nausea


– Food generally takes 4 hours to clear stomach and upper GI tract

– Liquid supplements clear stomach and upper bowel before game time, settling the stomach and making available nutrients


Eating 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 (variety)• Nutritional information posting


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

• 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 becomes to consume more CHO’s as a result

• Hyperinsulinemia– Elevated insulin in the blood which

contributes to individuals becoming overweight

– CHO restriction halts insulin cycle and improves glucagon production, enhancing fat burning and cholesterol removal from blood vessels

– Dietary changes result 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

• Decrease training at least 48 hours prior to event– Allows for clearance of metabolic waste

products• 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


Recommendations for Restoring Muscle Glycogen

After Exercise• When the time period between events is <8

hours– Consume CHO ASAP to maximize recovery

• Complete restoration requires 20-24 hours• Consume 0.45-0.55 grams of CHO per pound

of body weight for each of the first 4 hours– Utilize nutrient rich carbohydrate foods

• For a 24 hour period, 2.3 – 5.5 grams of CHO should be consumed per pound of BW


• Pasta, potatoes, oatmeal and sports drinks are recommended

• The addition of protein to carbohydrate supplements has been shown to enhance aerobic endurance– The reason behind this is unknown– Evidence supports a 4:1 ratio of CHO:PRO

• Other ratios (1:1; 3:1) have also been suggested• Peanut butter and tuna are good sources of

protein


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


Body Composition and Weight Control

• 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 individual displaying discipline relative to types and quantities of food


Body Composition

• Ideal body weight = age-related height/weight chart– Inaccurate due to broad ranges and failure

to take individual body types into consideration

• Health and performance may be best indicators

• Fat vs. nonfat components of body = body composition


• Non-fat or lean tissue (lean body weight)– bone, muscle, tendon, connective tissue

• Body comp is the relationship between fat tissue and lean body tissue

• Averages– Female 20-25% body weight = fat– Male 12-15% body weight = fat– Should not fall below 3% and 12 % for

males and female respectively• Results in loss of essential fat padding for

organs


• Overweight = excess body weight relative to size and stature

• 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 fat– Number of cells

• Proliferation or hyperplagia of fat cells occurs from birth to puberty

– Size of cells• Increase/decrease over time until adulthood relative

to caloric balance© 2011 McGraw-Hill Higher Education. All rights reserved

– Change of weight = change in size of adipose cell not the number of cells

• 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


Assessing Body Composition

• Several methods– Hydrostatic weighing, bioelectrical

impedance, skinfold thickness measures– Skinfolds based on the fact that 50% of

body fat is subcutaneous• Utilize skin fold calipers• Relatively low accuracy but is easy to learn and

utilize• Error is + 3-5%


Figure 5-5


• 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 between points– Based on principle that electricity will flow

through path of least resistance– Fat = good insulator– Water = good conductor– Impacted by levels of hydration– Expensive equipment


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 >25 indicate excess body fat• BMI 25-30 indicates overweight• BMI >30 indicates state of obesity


Assessing Caloric Balance

• Caloric balance = Calories consumed - calories expended

• Positive caloric balance results in weight gain and vice versa for negative caloric balance

• Can be calculated through accurate record keeping of calories consumed and expended relative to metabolic and activity needs– 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)


• Caloric Intake– Carbohydrate = 4 calories/gram– Protein = 4 calories /gram– Fat = 9 calories/gram– Alcohol = 7 calories/gram

– College athletes consume 2000-5000 calories/day

– Endurance athletes may consume as many as 7000 calories


Methods of Weight Loss

• Exercise or dieting alone is ineffective over the long run

• Dieting alone results in lean body tissue loss– Should not drop below 1000-1200 calories for

women and 1200-1400 for men• Exercising, while resulting in loss of fat

mass, will also enhance strength, cardiorespiratory endurance and flexibility


• The key is moderation– 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


Methods of Weight Gain

• Aim should be to increase lean body mass

• Increased physical activity (muscle work) and dietary modifications

• Approximately 2500 calories is required per pound of lean body mass, an increase 500-1000 calories per day

• A 1-2 pound per week gain is adequate


Disordered Eating

• Spectrum of abnormal eating habits– Mild food restriction, binging, purging,

bulimia, anorexia nervosa

• Multi-factorial– Social, familial, physiological,

psychological components


• More prevalent in athletic populations– Control over body weight/composition for

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 identified in females (can also be

found in males) ranging in age from adolescence to middle age

– Periods of starvation, bingeing (thousands of calories) and purging through vomiting, fasting and laxatives/diuretics


– Characteristics• Typically bulimic athletes are white, middle to

upper-middle class• Perfectionist, obedient, over-compliant, highly

motivated, successful academically, well-liked, and a good athlete

• 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


– Binging does not include celebratory overeating that may occur during the holidays or other events

– Binging is a loss of control over one’s eating; the resultant guilt drives he/she to vomit• Bulimics experience this scenario repeatedly


• 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– While the individual tends to be too thin

they continue to feel fat– Deny hunger and are hyperactive– Highly secretive


• Early intervention is critical with eating disorders– Empathy is a must

• Psychological counseling is key• Must have individual 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• No 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 © 2011 McGraw-Hill Higher Education. All rights reserved

Female Athlete Triad

• Potentially fatal problem• Combination of eating disorder,

amenorrhea 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


© 2011 mcgraw-hill higher education. all rights reserved chapter 5: nutrition and supplements

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