Chapter 9 Shit Flashcards
What are the 3 primary sports nutrition professionals?
Sports dietician
team physician
sports nutrition coach
What is a sports dietician?
-Registered dietician with specific education in sports nutrition
-Distinguished by academy of nutrition and dietetics
+Board certified specialist in sports dietetics
-Conducts dietary needs analysis on an individual basis
What is a team physician?
-Responsible for overseeing team’s overall medical care
-Works with sports dietician
+May work to help athletes with:
++Eating disorders
++Nutrition deficiencies
++Specific disease states (i.e. diabetes)
What is a sports nutrition coach?
-Not a registered dietician
-Basic training in nutrition and exercise science
-Can provide basic nutrition education and suggestions
-Can pursue additional sports, nutrition certifications through various certifying agencies (ISSA, ACE, etc)
What is the food guidance system recommended for s+c professionals called?
myPlate
What is myplate?
-Food guidance system created by USDA
-Based on 2010 dietary guidelines for americans
-Icon of five food groups based on a mealtime visual of a place setting
-Includes calorie guidelines and portion recommendations for:
+Fruit
+Grains
+Protein
+Oil
-Geared towards individuals getting less than 30 minutes of moderate activity most days
+Must be adjusted for physically active individuals
What deficiencies could you acquire if you exclude dairy and animal meat?
-dairy can result in calcium, potassium, and vitamin d deficiencies
-excluding animal meat can result in a b12 deficiency
What are the 3 macronutrients?
carbs, fats, protein
What is DRI?
-dietary reference intake
-Complete set of nutrient intakes for evaluating and planning diets for healthy individuals
-Evaluated based on the body of literature regarding nutrient intake and chronic disease reduction
-Assessed based on intake over several days due to typical daily variations in dietary intake
-Include RDAs, AI, UL, and EAR
What are RDAs?
-Recommended dietary allowance (RDA)
-Average daily nutrient requirement adequate for the needs of most healthy people in each life stage and sex
What is AI?
-Adequate intake (AI)
-Average daily nutrient requirement adequate for the needs of most healthy people in each life stage and sex
What is UL?
-Tolerable upper intake level (UL)
-Maximum average daily nutrient level not associated with adverse health effects
-Intakes above UL increase risk of adverse effects
-Represents intake from all sources including food, water, and supplements
What is EAR?
-Estimated average requirement (EAR)
-Average daily nutrient intake level considered sufficient to meet the needs of half of the healthy population within each life stage and sex
What are common nutrient deficiencies?
-High prevalence of magnesium and vitamin E deficiency in all population subgroups
-Average fiber and potassium intake below DRI for individuals above age 2
-Fiber, potassium, calcium, and vitamin D listed as nutrients of concern
-B12 absorption often an issue among adults over age 50
What is protein?
-One of the three primary macronutrients
-The primary structural and functional component of every cell
-Used for growth and development and to build and repair cells
-Components of enzymes, transport carriers, and hormones
-Composed of amino acids
What are amino acids?
-Nitrogen-containing molecules that can join in groups of dozens to hundreds
+Building blocks for the thousands of different proteins found in nature
+Made of carbon, hydrogen, oxygen, and nitrogen
-Human body proteins formed from combinations of individual amino acids
+4 non-essential amino acids
++Can be made by the body
+9 essential amino acids
++Can’t be made in the body
++Must be obtained through diet
-8 conditionally essential
+Required during times of illness or stress
+Must be obtained through diet
How are amino acids joined?
peptide bond either dipeptide (2 linked) or polypeptide (3+)
Where is the majority of the protein reserve stored?
-50% in skeletal muscle
-additional 15% in structural tissues
-remainder in visceral tissues like liver and kidney and bones
How do you figure out how digestible a protein is?
-Calculated by how much of the proteins nitrogen is absorbed during ingestion
-Reflects ability to provide amino acids for growth, maintenance and repair
-Animal-based proteins contain all essential amino acids
-Soy is the only plant-based protein with all eight amino acids
-Plant protein digestibility lower than animal protein
+Can be improved via processing and preparation
What are PDCAAS?
-Protein digestibility correct amino acid score (PDCAAS)
+Accounts for bioavailability and provision of essential amino acids
+Does not take into account other compounds in the food and how they affect bioavailability
++Antinutrient factors can reduce protein bioavailability
+++I.e. browning of foods can decrease the bioavailability of certain amino acids
How can vegetarians and vegans can meet amino acid requirements?
Eating a variety of plant based protein sources
What’s another phrase for protein requirement?
-Amino acid requirements
-Sedentary healthy adults need amino acids due to constant cellular turnover
-Breakdown and regeneration of cells requires amino acids
-Some amino acids can be recycled but must be supplemented via diet
What is the recommended protein amount in men and women 19+?
-0.8 grams per kilo of body weight
-Children, teens, pregnant, and lactating women require more
How should you adjust protein intake when calories are being reduced?
up it
What is AMDR?
-Acceptable macronutrient distribution range (AMDR)
-5-20% total calories from protein for children 1-3 years
-10-30% in children 4-18 years
-10-35% for adults above 18 years
-For every 100 calories below 2000/day recommended to increase protein by 1%
What happens to blood lipids when RDA for protein is too low?
-Research suggests that higher-protein, lower-carb diets favorably affect blood lipids - especially in obese individuals
+May decrease risk factors for cardiovascular disease and metabolic syndrome
What happens to Bone health when RDA for protein is too low?
-Protein contributes to 50% of bone volume and 33% of bone mass
+Effect may be in part due to influence of IGF-1
++Promotes bone and muscle formation
-Supplemental protein above 0.7g to 2.1g/kgbw increases calcium excretion and intestinal calcium absorption
-Protein intake below 0.7g/kg*bw power suppresses intestinal calcium absorption
What happens to weight management when RDA for protein is too low?
-Protein promotes satiety in a dose-dependent manner
+Greater protein leads to greater satiety
+The effect depends on:
++Timing
++Additional foods consumed
++Time until next meal
++Type of protein
-Protein has the greatest thermic effect
+Requires more energy to digest than carbs or fat
What happens to Muscle protein synthesis when RDA for protein is too low?
-Amino acids needed for growth, tissue repair, and enzyme synthesis
-Athletes and intense exercisers require more protein
+Endurance athletes - 1.0-1.6g protein/kgbw/day
+Strength athletes - 1.4g-1.7g protein/kgbw/day
+Combination athletes - 1.4g-1.7g protein/kg*bw/day
-Post exercise protein may improve muscle protein synthesis
+Muscle tissue most receptive to amino acids after work out
+20-48g protein in a 4:1 or 3:1 carb-to-protein ratio may stimulate muscle protein synthesis - may depend on leucine content
-Healthy individuals can safely consume protein far above RDA values
+Once concern - consistent high-protein intakes may decrease consumption of carbs and fats - therefore long-term excess protein intake above the athlete recommendations is not recommended
What are the 4 non-essential amino acids that the body makes?
Alanine
Asparagine
Aspartic acid
Glutamic acid
What are the 9 essential amino acids that can’t be made by the body?
-Histidine
-Isoleucine
-Leucine
-Lysine
-Methionine
-Phenylalanine
-Threonine
-Tryptophan
-Valine
What are the 8 conditionally essential amino acids that are required during times of stress or illness that aren’t produced by the body.
Arginine
Cysteine
Glutamine
Glycine
Proline
Serine
Tyrosine
What are carbohydrates?
-Composed of carbon, hydrogen, and oxygen
-Encompass a wide range of compounds that are formed of sugar molecules linked together
-Considered non-essential due to the body’s ability for gluconeogenesis from amino acids and other substrates
How are carbs classified?
-based on the number of saccharide (sugar) molecules linked together
+Monosaccharides (glucose, fructose, galactose) - single-sugar molecules
+Polysaccharides - multiple-sugar molecules
What is glucose?
-circulating sugar in blood - used as energy substrate in cells
-Glucose molecules also make up glycogen
-In food - glucose typically combined with other monosaccharides to form various sugars
What are monosaccharides?
-single sugar molecules
-Glucose
-Dextrose - isomer of glucose found in candy and sports dirnks
-Fructose - same chemical formula as glucose with different arrangement
+Sweeter than glucose
+Occurs naturally in fruits and vegetables
+Causes less insulin secretion than other sugars
-Galactose - combines with glucose to form lactose - the sugar found in milk
What are disaccharides?
-2 simple sugar units joined together
-Sucrose - table sugar
-Combination of glucose and fructose
-Occurs naturally in most fruits
-Crystalized from sugar cane and sugar beets
What is lactose and where is it found?
-glucose + galactose
-only found in mammalian milk
What is Maltose and where is it found?
-glucose + glucose
-Primarily formed by polysaccharide breakdown during digestion
-Also occurs during fermentation - primary sugar found in beer
What are polysaccharides?
-Complex carbs - contain up to several thousand glucose units
-Most important nutritional polysaccharides
+Starch - storage form of glucose in plants
+Fiber - constituent of plant-cell walls
++Partially resistant to digestion - has varying physiological effects
+Glycogen
What is the glycemic index (GI)?
-Ranks carbs according to how quickly they are digested and absorbed
-Reflects how quickly the carb raises blood glucose
-Ranked based on reference food - usually white bread or glucose - which is standardized at a GI of 100
-Low-GI foods are digested and absorbed more slowly
+Causes a smaller rise in blood glucose and insulin response
-Can be used to help monitor blood sugar levels - Low GI diets may help prevent obesity
-GI has issues that limit its accuracy
+Published GI values for a given food vary due to testing differences, ripeness of food, cooking method, and storage
+Consuming carbs as part of a meal or in varied quantities affects the GI
-Recommended to eat higher GI foods during and immediately following exercise to replenish glycogen
-Effect of low vs high GI foods pre-exercise unclear - may vary athlete to athlete
What is glycemic load (GL)?
-Takes portion of food as well as GI into account
-More realistic of gauge of glycemic response to food
-GL=GI of food x amount of carbohydrate in the serving of food divided by 100
-High GL expected to lead to greater blood sugar and insulin release
-Low GL diet combined with exercise shown to improve insulin sensitivity in older obese adults
What is DRI for fiber and what is it found in?
-DRI for fiber between 21-29g/day for women
-30-38g/day for men
-Commonly found in fruits, vegetables, nuts, seeds, legumes, and other whole-grain products
What are low fiber diets associated with?
Constipation
Heart disease
Colon cancer
Type 2 diabetes
What are carb requirements for an aerobic endurance athlete?
-Aerobic endurance athletes
+90 minutes plus per day at moderate intensity or HIIT athletes
-8-10 g carb/kg bw/day
-I.e. distance running, cycling, soccer, basketball
-Recommended to consume 1.5g high-GL carb/kg bw a day within 30 minutes of aerobic endurance training to stimulate glycogen synthesis
-Athletes who do not train every day have a longer window to replenish glycogen
-Athletes can adapt to low-carb diets despite the performance benefit of glycogen
+Some athletes can use carb-reduction to decrease caloric intake
What are carb requirements for strength, sprint, and skill athletes?
5-6 g carbohydrate per kg bw a day
What is fat?
-energy source
-Fatty acid chains - contain carbon, oxygen, and hydrogen
+More carbon and hydrogen relative to oxygen - more energy per gram than carbs
+9 kcal a gram
-Stored as energy in adipose tissue
-Insulates and protects organs
-Regulates hormones
-Carries and stores fat-soluble vitamins A, D, E, and K
What is saturated fat?
-No double bonds
-Carbon molecules saturated with hydrogen
-Used for certain physiological and structural functions
-Body can produce saturated fat - no dietary requirement
What is unsaturated fat?
- contains one or more carbon molecules with double bond
-More chemically reactive than saturated fat
-Monunsaturated fat - one double bond
-Polyunsaturated fat - two or more double bonds
What are omega 3 fatty acids?
-Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA)
+Found in fatty fish
+Tied to a dose-dependent decrease in triglycerides and blood pressure
-Alpha-linolenic acid (ALA)
+Found in flaxseeds, walnuts, soybean and canola oil
+Can be inefficiently converted to EPA (~5%) and DHA (less than 0.5%) in adults
What foods contain omega 6 fatty acids?
soybean, corn, and other vegetable oils
What is cholesterol?
-Waxy fat-like substance
-Important structural and functional component of all cell membranes
What is cholesterol used in production of?
-Bile salts
-Vitamin D
-Hormones
+Sex hormones
+Cortisol
What can high levels of cholesterol lead to?
-atherosclerosis - hardening of arteries due to plaque buildup on artery walls
-Elevated cholesterol is a risk factor for heart disease and stroke
-High levels of low-density lipoproteins (LDL), very low density lipoproteins (VLDL), and triglycerides in blood are associated with increased risk of heart disease
-High saturated and trans fats, weight gain, and anorexia can all increase LDL
-VLDL associated with increased carbohydrate intake
-High density lipoproteins (HDL) are associated with reduced heart disease
What can increase triglycerides?
-High intake of refined carbohydrates, alcohol, weight gain, and very low fat diets can increase triglycerides
-Sedentary lifestyle, being overweight, smoking, genetics, and certain diseases and medications can increase these numbers
-Recommended to limit saturated fat to less than 10% of total calories
-Avoid hydrogenated/partially hydrogenated oils
-Replace saturated fat with unsaturated fat - especially polyunsaturated fat
What is the relationship between fat and athletic performance?
-Fat is a source of energy during exercise
-Compared to carbs fat sources are large and offer a vast source of fuel
-Ex. 160 lb 4% body fat runner has 22400 calories stored within fat tissue
-At rest and low intensity exercise most energy is produced from fatty acid oxidation
-As intensity increases there is a gradual shift to carbs for energy
-Consistent aerobic training increases muscle capacity to use fatty acids
-High-fat, low-carb diets cause body to adapt over time to increased use of fatty acids for energy
+Effect of this type of diet will vary individual-to-individual
What are vitamins?
Organic substances needed in small amounts to perform specific metabolic functions
Typically act as co-enzymes to facilitate numerous reactions in the body
What are the 2 types of vitamins?
water and fat soluble
What are water soluble vitamins?
-Include b vitamins and vitamin c
-Dissolve in water and transported in blood
-Not stored in body in high amounts
-Consumed in diet and excreted in urine
+Exception is b12 which can be stored in the liver for years
What are fat soluble vitamins?
-A, D, E, K
-Stored in fat tissue and carried by fat in the blood
What are the adverse effects of excess vitamin A?
-Liver damage
-Intracranial pressure
-Dizziness
-Nausea
-Headaches
-Skin irritation
-Bone and joint pain
-Coma
-Death
-Excess Vitamin a typically occurs through a high intake of vitamin A supplements
What can excess vitamin d lead to?
-Heart arrhythmias
-Blood vessel and tissue calcification through increased blood calcium
-Heart, blood vessel, and kidney damage
What does excess vitamin e lead to?
-acts as anticoagulant
-Excess vitamin E can lead to increased risk of:
Hemorrhagic stroke
What are minerals?
-Inorganic substances
-Contribute to structure of:
+Bone
+Teeth
+Nails
-Perform a variety of metabolic functions
-Major minerals
+Calcium
+Phosphorus
+Magnesium
+Iron
+Electrolytes
++Sodium
++Potassium
++Chloride
What is iron?
-Essential for functioning and synthesis of hemoglobin
-Components of myoglobin protein for oxygen transport
What are the two kinds of iron?
heme and nonheme
What is nonheme iron?
-Found in non-meat foods including vegetables, grains, and iron-fortified cereals
-Plant compounds can decrease iron absorption
-Absorption can be increased by eating iron with vitamin C
-Iron supplements vary in bioavailability and are affected by other compounds in the supplements
+Only an RD or MD should advise which specific iron supplements/combinations are needed on an individual basis
What is heme iron?
-Iron found in hemoglobin
-Only found in meat
-Most absorbable source of iron
+Absorption not affected by other substances
What is anemia?
-iron deficiency
-Most common nutrient deficiency in the world
-Approximately 16% of teenage girls 16-19 and 12% of women between 20-49 are iron deficient
What are the 3 stages of iron deficiency?
Depletion
Marginal deficiency
Anemia
What are symptoms of iron deficiency?
Weakness
Fatigue
Irritability
Poor concentration
Headache
Decreased exercise capacity
Hair loss
Dry mouth
Pica (desire to eat nonfood substances)
How is calcium important?
-Calcium intake through childhood and adolescents essential for developing strong bones
-Helps bones grow in length and density
-Maintains bone density in adults
-Calcium deficiency causes body to take calcium from bones - decreases BMD
-Insufficient calcium decreases peak bone mass and increases fracture risk later in life
-15% of 9-13 year old females and less than 10% of females ages 14-18 get adequate intake of calcium from diet alone.
-Athletes should be encouraged to eat dairy and calcium-rich foods
-RD or MD can recommend a calcium supplement on an individual basis
What is nutrient density?
-Not specifically defined
-Generally, refers to foods high in fiber, vitamins, and minerals relative to the calories per serving
+Milk
+Veggies
+Protein foods
+Grains
What is caloric density?
-Foods refer to foods high in calories but low in vitamins and minerals
-chips/snacks
-Candy
-Desserts
-generally recommended to avoid these
What is water’s role in the body?
-Water is the largest component of the body - represents 45%-75% of a person’s body weight
+Acts as a lubricant, shock absorber, building material, and solvent
+Essential for body temperature regulation via sweat
+Transports nutrients and removes waste
+Maintains fluid balance and normal blood pressure
Why is hydration important?
-Maintaining hydration status crucial for athletes due to fluid loss from sweating
-Fluid loss from sweat can quickly lead to hypohydration
+Increases core blood pressure
+Decreases blood plasma volume
+Increases heart-rate and perceived exertion
+The body cannot sweat output to keep up with core-body temperature increase
How does exercising hot environments effect an athlete?
-Causes greater sweat volume
-Decreased electrolyte content of sweat
-Lower temperature for onset of sweating
-Decreased risk of dehydration - risk of dehydration greater early in the season
Why is hydration more imperative for kids?
-Increased skin surface area relative to body mass
-Increased heat production during exercise
-Decreased ability to dissipate heat via sweating
-Decreased sensation of thirst compared to adults
-Sickle-cell, cystic fibrosis, and some other disease increase risk as well
What can mild dehydration (2-3% weight loss) do to performance?
-Increased fatigue
-Decreased motivation
-Decrease neuromuscular control, accuracy, power, and endurance
-Decreased stroke volume and cardiac output
-Decreased blood pressure
-Reduced blood flow to muscles
-Increased heartbeat
-Exacerbate symptomatic exertional rhabdomyolysis
-Increase risk of heatstroke and death
What is considered adequate water intake?
-3.7L for men
-2.7L for women
-3.0L for pregnant women
-3.8L for lactating women
What is included in water intake?
All fluids, including soda, coffee, tea, etc contribute to meeting water needs
What are the best ways to prevent dehydration?
-Prevent water losses exceeding 2% of body weight
-Assessing pre and post-training weight can indicate hydration status
+Can be used to acutely assess hydration as well as detect chronic dehydration
+Allows individual assessment of weight lost via sweat to aid water intake guidelines per athlete
What are fluid intake guidelines preexercise?
Athletes should have urine specific gravity of less that 1.020 and must prehydrate several hours before exercise
What are fluid intake guidelines during training?
-Children and adolescents
-88lb children should drink 5 oz of cold water or flavored, salted beverage every 20 minutes during training
-Adolescents weighing 132 lbs should drink 9 oz of cold water or flavored salted beverage every 20 minutes
How should adults hydrate in hot weather?
consume a salted beverage with 460-690mg sodium and 78-195mg potassium per liter, with a carb concentration of 5%-10%
How should people hydrate after training?
-Athletes should consume adequate food and fluids in addition to sodium to restore hydration
-If less than 12 hours before next exercise - 1.5L electrolyte drink for each KG lost
Is thirst a reliable indicator of hydration?
no
What are the biomarkers of hydration status?
-Total body water
+Low practicality
+<2% EUH cutoff
-Plasma osmolality
+Medium practicality
+Reflects acute and chronic hydration status
<290mOsmol EUH cutoff
-Urine specific gravity
+High practicality
+Reflects chronic hydration status
<1020g/mh EUH cutoff
-Urine osmolality
+High practicality
+Reflects chronic hydration status
<700 mOsmol EUH cutoff
-Body weight
+High practicality
+Reflects acute and chronic hydration status
<1% EUH cutoff
What are electrolytes?
sodium, potassium, magnesium, calcium
What do electrolytes do?
-are essential to muscle contraction and nerve conduction
-Electrolyte balance disturbance can potentially interfere with performance
Why does sodium loss vary in athletes?
Athletes may consciously choose higher sodium foods, salt their food, or add electrolytes to sports drinks
What is hyponatremia?
- occurs when blood sodium drops below 125 mmol/L - leads to
+Intracellular swelling
+Headaches
+Nausea
+Vomiting
+Muscle cramps
+Swollen hands and feet
+Restlessness
+Cerebral edema, seizures, coma, brain stem herniation, respiratory arrest, and death when blood sodium drops below 120mmol/L
