Nutrition and Bioenergetics Exam 2
Phosphorus is crucial for bone and tooth formation. What other roles important roles does P play in the body?
crucial for bone and tooth formation, energy intermediates, phospholipid membrane, buffer acid end products of energy metabolism, helps regulate cellular metabolism as an enzyme
Your brother is about to head to a 12 week long intense Marine Corps boot camp. Based on the Nindl et al. 2007 investigation what changes do you predict will occur?
decrease in strength and power, loss of fat and fat-free masses, alterations of circulating hormones, decrease in lower body power, decrease in incremental dynamic lift, decrease in vertical jump height
What are the 3 components of the Female Athlete Triad? What is the cause of the Female Athlete Triad?
disordered eating, osteoporosis, amenorrhea Cause: inadequate caloric intake, abnormally low BF% leads to disruption of estrogen production, and low calcium intake leads to bone mineral density loss and amenorrhea
Where does absorption of minerals occur?
small intestine
Where does absorption of vitamins occur?
small intestine
What are three functions of the hypothalamus?
temperature regulation, thermostat, protects body
Before offering any opinions concerning if their athletes need to lose or gain weight/ alter body composition, what questions should a coach ask him or herself?
-Reviews of energy (caloric) intake vs. expenditures should be done 1) is nutritional intervention needed, how will intervention affect the athlete's physiological and psychological health 2) is intervention for aesthetics or performance, how do you assess acute or chronic changes in body composition in regards to what type of tissue is experiencing atrophy 3) if caloric restriction is advised, will training capacity/performance be compromised
Mild to moderate work and routine physical training results in whole-body sweat losses of about ______?
0.8-1.4 liter/hour
If an athlete loses 3 kg of body weight during a football practice, how many liters of water does he need to drink to replace his sweat loss?
1 kg=1 liter, 3 liters
Name some roles that Vitamin C plays in the body.
1. Enhances iron absorption and possibly heat acclimatization 2. Antioxidant 3. synthesis of collagen and carnitine 4. Facilitates iron availability 5. Cofactor in some hydroxylation reactions 6. decreases risk for some types of cancer
What three ways do vitamins enter the body?
1. From fruits and vegetables 2. From foods that animals eat and then we eat animals 3. multivitamins
Describe other methods that may be used to estimate body fat percentage.
1.) air displacement plethysmography = uses air displacement rather than water immersion 2.) DXA (dual x-ray absorptiometry) = a test that measures the density of your bones. 3.) bioelectrical impedance analysis = provides estimates of body water from which body fat is calculated using selected equations. 4.) skinfold measures
What are some of the roles that calcium plays in the body?
1.) blood clotting (fibrin) 2.) nerve transmission (Ca++) 3.) muscle action 4.) enzyme activity 5.) synthesis of calcitriol (vitamin D formation), 6.) disease prevention and weight management, 7.) structural substances for bones and teeth
Describe the general health risks associated with hypohydration. (loss of fluids)
1.) increased cardiovascular strain 2.) temperature 3.) loss of orthostatic pressure 4.) muscle weakness/muscle cramping (loss of Na and K 5.) diminished cognitive function, sleepiness or tiredness 6.) thirst/decrease urine (dark color) output 7.) few or no tears when crying, 8.) headache/dizziness or lightheadedness
Name the 3 protective mechanisms of estrogen on bone health.
1.) increases intestinal calcium absorption 2.) reduces urinary calcium excretion 3.) facilitates calcium retention by bones
What's the AI for calcium for men and women?
1000mg/day
At what % loss of body weight through sweating does aerobic performance tend to decrease?
2
What and how much to drink after exercise
2-3 cups per every pound lost during exercise
What and how much to drink pre exercise
24 hours before = meet predetermined fluid needs 2-3 hours before = 2-3 cups 10 - 20 minutes before = about 1 cup
What's the UL for calcium for men and women?
2500mg/day
Name the 4 fat soluble vitamins.
A, D, E, K
Hormones: ADH and renin-angiotensin system. How do they work?
Aldosterone + ADH hormones that help to conserve as much water as possible ADH: -Released from posterior pituitary -Acts to retain water (kidneys, sweat glands) -Increased water re-absorption -↓ urine flow Stimulated by: -osmoreceptors (brain, liver, etc) -SNS -stress -elevated temperature -arterial baroreceptors 2.) Renin-Angiotensin System → release of Aldosterone (from adrenal gland) acts on kidneys to: -Conserving/reabsorbing Na+ -Conserves water -Constricts vessels -↑ BP20
How are the B-complex vitamins incorporated into the production of ATP?
B vitamins act as a coenzyme, and are essential for processing carbohydrates, lipids and proteins in order to generate energy.
Name the water soluble vitamins.
B-complex vitamins, Vitamin C and choline
What does BMI stand for? Is BMI an accurate predictor of percent body fat?
Body Mass Index, divide weight in kg by height in m^2; correlates fairly strongly with body fatness but doesn't give estimate of BF%, BMI can misclassify up to one of four people, doesn't account for fat distribution or LBM--> may misclassify frail/sedentary or very muscular people
What roles do Ca and Vitamin D play in bone remodeling? What is the relationship between Ca and Vitamin D?
Calcium: deposited as salt in bones using the hormone calcitonin Vitamin D: facilitates calcium uptake
How can one measure hydration status? What is best indicator of change in hydration status?
Euhydration (normal hydration status) Indicator: change in total body water, plasma osmolality, urine osmolality, urine specific gravity, urine color, pre/post exercise change in body mass
Explain the differences between fat and water soluble vitamins.
FAT: fat-soluble vitamins do not dissolve in water. Fat-soluble vitamins are most abundant in high-fat foods and are much better absorbed into your bloodstream when you eat them with fat. WATER: Water-soluble vitamins dissolve in water, which means these vitamins and nutrients dissolve quickly in the body.
What does FRS stand for? What do FRS do? What vitamins serve as FRS?
FRS= free radical scavengers What do they do: stop ROS from spreading their destructive effects by being able to accept the extra electron from the ROS and forming a stable structure; vitamins A (+ beta carotene), E, and C
What regulates thirst stimuli?
Increased plasma osmolarity Decreased Plasma volume Angiotensin II Angiotensin III Dry mucous membranes Psychological factors
What function does Fe play in the body? How is Fe important to athletic performance? What food sources containing Fe are the most absorbable? What Vitamin increases Fe absorption?
Iron is an essential element for blood production. We need sufficient oxygen transport to enable our muscles to execute work. Iron is especially important for athletes due to the high work demands placed on their muscles during training and competition. Meat, fish and poultry. Vitamin C
Give the BMI score and classification for the following individuals: Kevin is 1.83 m tall and weighs 94 kg. Samantha is 1.54 m tall and weighs 45 kg.
Kevin = 51 Samantha = 29
What does the term "mineral bioavailability" mean? What three factors determine mineral bioavailability? How?
Means: the capacity to absorb and use minerals in food Factors: 1)food type = 2)mineral-mineral interaction, 3) vitamin-mineral interaction
What is the Fe RDA for men? What is it for women? Why is there a difference between genders?
Men 8 mg/day Women 18/mg day women need more iron than men because they lose it through menstruation, pregnancy and breastfeeding.
OB-gene, Leptin and Set Point Theory. How do they relate?
OB-gene: stimulates production leptin; disrupts hormonal signals that regulate metabolism, fat storage, and appetite; stimulates production of body fat Leptin: decreases urge to eat when food intake coincides with ideal fat stores; suppress appetite; depressed receptor sensitivity signals brain that the body lacks fat reserves--> overeating; normal levels signal to the hypothalamus to maintain food intake; below normal levels, signal brain to increase appetite; elevates metabolic rate Set point theory = Well-regulated internal control mechanism (genetic) → maintains a preset level of body weight and/or body fat. -%BF decreases below one's pre-established set point → conserve and/or replenish body fat
Over vs under hydration
Over = rare because water and sodium will be excreted if there's too much; water intake > water loss Under = water intake < water loss
Why is it easier for men compared to women to lose weight?
Physiologically, men are built to burn fat more quickly. They have more lean muscle mass and a naturally higher metabolic rate.
What are some requirements for gaining weight?
Regular participation in a RT program -Hypertrophy • + Energy balance + Nitrogen balance Achieving a Positive Energy/Nitrogen Balance: •Caloric intake > caloric expenditure
Why having Sodium and Potassium is beneficial?
Sodium = stimulates fluid movement across the membrane of the small intestine-- important in rehydration, helps maintain thirst, delays urine production Potassium = thought to promote intracellular hydration
What does ROS stand for? What do ROS do? How and where are they formed? Name some ROS.
Stands for: reactive oxygen species What do they do: formed when oxygen molecules "gain" an extra electron; they try to steal H+ molecules from (the cell membrane, DNA, RNA, lipids, and proteins) to make them return themselves to their stable state Examples of ROS: hydrogen peroxide (H2O2), superoxide (O2-), hydroxyl radical (HO-)
Why do diets fail? What are some problems with fad diets? What changes will occur with fad diets?
They're short term goals, the person doesn't make a lifestyle change FAD: weight loss is mostly water loss, supplements may be dangerous, may lack essential nutrients, metabolism may slow down if caloric intake is low, most are short term and don't work for people long term
What are phytochemical and their role in the body? Sources of phytochemicals
What: chemical substance from plants; consumption is associated with decreases in cardiovascular disease and cancers Sources: fruits, vegetables, grains, grapes (wine), tea, garlic and onions, tomato and tomato products
What are electrolytes? What are their roles in the body? What are the major electrolytes? What does ECF stand for? What does ICF stand for? What is the major electrolyte found in the ECF? ICF?
What: electrical conductance of nerve impulses and muscle action Roles: maintain plasma membrane permeability, regulate acid and base quantities in the plasma membrane, attribute to osmolality Major: Sodium, calcium, potassium, chloride, phosphate, and magnesium are all electrolytes Intracellular Fluid (ICF) - fluid found in the cells (major = potassium) ECF: Extracellular fluid (found outside cells) (major = sodium)
What is hyponatremia? What causes hyponatremia? Give a description of an athlete who would be most at risk to experience hyponatremia.
What: water intoxication/reduced sodium concentration in body fluids People: ultra-endurance athletes; overly abundant fluid consumption, female, small body mass, slow
Explain bone remodeling. Be sure to include the terms resorption, osteoblast, and osteoclast. Hormonal control? Osteoporosis.
a constant state of flux where bone is broken down and reformed •Resorption: breakdown of bones leading to high calcium that's circulating •Osteoblast: build bones, decrease resorption •Osteoclast: destroy bones, increase resorption •Osteoblast/clast activity is regulated by hormones and dietary and activity stressors Osteoporosis: progresses as bones lose their calcium mass (bone mineral content) and calcium concentration (bone mineral density); bones become porous and brittle; 90% of BMD for women occurs by age 17; UL 2,500 mg/d
What and how much to drink during exercise
about 1-1.5 cups every 10-20 minutes; water is excellent, sports beverages if taste is preferred over water, if practice or event lasts longer than 60-90 minutes, 6-8% CHO mix
Describe how the use of hydrostatic (underwater weighing) can be used to estimate body composition.
an object's loss of weight in water equals the volume of water that it displaces; SIRI equation: BF%=495/(body density-450)
What are the 7 major minerals needed by the body?
calcium, potassium, phosphorous, sulfur, sodium, chloride, magnesium
Your brother is about to head to a 12 week long intense Marine Corps boot camp. What nutritional advice would you give your brother to help him make it through training as strongly as possible?
carb load for a few days before the boot camp and as much as you can during-- ensures that glycogen levels are maximized, leading to longer exercise, consume food or drink during if at all possible-- this is where most of the energy will come from
How does restricting calories affect athletic performance? What would you recommend instead?
doesn't allow for enough energy; recommend an increase of 700 to 1000 kcal to a well-balanced daily meal plan, this will support a weekly 0.5 to 1.0 kg gain in lean tissue
Sweat evaporation is the primary route for humans to control body temperature in a hot environment. What conditions will increase sweat evaporation?
environmental temperature, clothing, air flow, acclimatization of athlete, gender, radiation (sun), humidity, altitude, hydration, body size/fatness, fitness level of athlete
What role does Vitamin E play in the body?
functions as an antioxidant to prevent cell damage
Sports drinks: benefits and recommendations.
hydrate effectively, replenish electrolytes, provide energy for working muscles to enhance recovery and speed performance
What are some common weight management concerns for athletes?
impact on performance, aesthetics/body image, weight classifications for competition, changing body composition-- increase muscle mass, decrease fat mass
What is the primary role of Vitamin K in the body?
important in blood clotting
Are minerals organic or inorganic? What does inorganic mean?
inorganic, meaning they don't contain carbon (derive from living matter)
What is meant by essential nutrients?
needed by the body, but can't be synthesized by the body so must be consumed in the diet
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What roles does Vitamin D play in the body? Older Adults?
promotes growth and mineralization of bones, increases absorption of calcium
Milk - new recovery drink. Why?
similar CHO and PRO content as many "CHO replacement drinks" that allow for the refueling of glycogen depleted muscles after a workout, also similar to "Fluid Replacement drinks" in its CHO as they both contain monosaccharides, whereas CR drinks contain more complex sugars
How does mineral-mineral interaction affect mineral bioavailability?
the more minerals there are, the more competition there is for transport
Fat cell development. Why do obese people gain weight more rapidly?
the number of fat cells increases during late childhood and early puberty, fat cells expand in size as they fill, when they reach a certain size they may also divide, with fat loss, fat cell size diminishes but the number of fat cells doesn't, having more fat cells makes you gain weight more rapidly lipoprotein lipase (LPL) promotes fat storage; LPL is located on fat cells, obese people have more fat cells and thus more LPL activity
How does food type affect mineral bioavailability?
the small intestine readily absorbs minerals in animal products because plant binders and dietary fiber are unavailable to hinder digestion and absorption, fiber blunts the intake of some minerals, fiber decreases absorption rate
Why older adults cannot rely on vitamin D synthesis from the sun?
their bones are degrading faster and so they need more vitamin D than what the sun provides in order to maintain the bone health they've been used to throughout their lives
What roles does Vitamin A play in the body?
visual pigment (used by rod cells at night-- night vision), management of epithelial tissues (skin cell formation)
How does vitamin-mineral interaction affect mineral bioavailability?
vitamin C increases iron absorption, vitamin D increases calcium absorption
Describe bone health through a woman's lifespan. What dietary factors play important roles in bone health? Explain in detail the role of physical activity in bone health.
•Genetics 60-80% •Estrogen: ↑production ↓ resorption → How? Lifestyle 20-40%