Chapter 18,22 Flashcards
What is the energy balance equation
change in body macronutrient stores = energy intake (food consumption) - energy expenditure (REE + PA/E + TEF)
what are the three things that change in body macronutrient stores
- fat (white fat cells)
- proteins (cellular proteins)
- carbohydrates (glycogen)
Does REE, TEF, or PA/E increase or decrease when indiviudals become more active
- REE (resting energy expenditure) decreases
- PA/E (physical activity/exercise energy expenditure) increases
- TEF (thermic effect of food) remains the same
What is dietary reference intakes
quantity of nutrients needed for proper function and health
What are the 6 things that are under dietary reference intakes (DRI’s)
- Tolerable upper intake level: how much you can consume before it becomes toxic
- recommended dietary allowance (RDA)
- adequate intake
- estimated average requirement
- estimated energy requirement
- acceptable macronutrient distribution range
what are the two subgroups of dietary reference intakes
- Recommended daily allowance
- adequate intakes
what is recommended daily allowances
quantity of each nutrient to meet the needs of nearly all (97-98%) healthy persons within a specific life stage
* if certain pathology or issue: not always correct for every person
what is adequate intakes
- recommended daily intake based on apparently heathy people
- used when an RDA cannot be determined
use second
What is the equation for BMI
BMI = body weight (kg) / height (m) ^2
at what lifestyle is the BMI accurate
only with sedentary individuals
What is the estmated energy requirement
average dietary energy intake predicted to maintain energy balance considereing age, sex, weight, height, and level of physical activity
What are the 6 classes of nutrients
- carbohydrates
- fats
- proteins
- water
- minerals
- vitamins
What are the two classes of nutrients
- macronutrients
- micronutrients
What are the nutrients in macronutrients
water, CHO, fat, proteins
What are the nutrients in micronutrients
vitamins, minerals, trace elements
what are carbohydrates
sugars and starches
* can be digested and metabolized for energy
* blood glucose is maintained with narrow limits by the endocrine system
- adult daily recommended intake = 130 g/day
dietary fiber
* cannot be digested or metabolized
* provides sense of fullness (satiation) during a meal
* reduces transit time in intesting - binds to bile and decreases cholesterol
- riber recommendations = higher for men than women
Explain exercise intensity and fuel selection
with higher intensity you want to increase CHO utilzation and decrease fat utilization
Explain exercise duration and fuel selection
with higher intensity you want to increase fat utilzation and decrease CHO utilization
Explain how time to exhaustion is related to intitial muscle glycogen stores
- muscle glycogen is NOT the determining factor in exercising to exhaustion
- other factors like ATP-PCr availability and amount of H+ limits the amount
Endurance performance is improved by what type of diet? What does this do for the body and how long does will it last?
high carb diet
* increase muscle glycogen performance and time
* most important in events at high intensity lasting over an hour (less than hour dont need to fuel)
Glycogen depletion leads to what following exercise
greater synthesis of glycogen following exercise
increased glycogen synthase activity
Explains how different a low vs. high CHO diet is influenced during repeated days of training
- high CHO – depleted but then recovery is dependent on how much CHO consumed – eat more = recover better –> effect wehre glycogen levels are for the next exercise
- low CHO – depleted but then eat low amount of CHO so cannot recover the amount of CHO (small increase) before next exercise –> continuously decrease muscle glycogen level
Explain what muscle glycogen supercompensation is in the Classical method
- prolonged stremous exercise to deplete glycogen stores
- high-fat/protein diet for 3 days while continuing to train
- 90% CHO diet for 3 days w/ inactivity
( must completey deplete muscle glycogen stores)
result is w/ resting and 90% CHO diet glycogen increases exponentially
Explain what muscle glycogen supercompensation is in the modified method
- tapering workouts (90-40 mintues) over several days while eating 50% CHO diet
- two days of 20 min workouts while eating 70% CHO diet
- day of rest eating 70% CHO diet before event
Explain the difference in outcomes bewteen the classical and modified muscle glycogen supercompensation plan
there are realy no differences in the outcomes between the two plans
What is the major purpose of glycogen “loading” prior to prolonged exercise
- improved performance
- extend duration of muscle glycogen
When should CHO be intaken prior to exercise? when is the worst time
should eat 2-3 hours before exercise or 5 minutes before exercise (avoid decrease of blood glucose and the same time as exercising –> more decrease b/c more translocation of GLUT4)
- avoid eating 30-45 minutes prior to exercise b/c –> faster rate of muscle glycogen utilization and fall in blood glucose during exercise
as soon as you have a meal there is a spike in insulin –> immediate drop of blood glycogen
During exercise doing what can help to maintain plasma glucose even when glycogen is depleted
carbohydrate ingestion during exercise can maintain plasma glucose — fatigue prolonged and improves performance
When is the best time to intake CHO on race day
throughout exercise or prior to fatigue (30-60g CHO/hr required)
- if you ingest constantly you will maintain blood glucose
- if you wait to ingest CHO until feel weakening it might be too late in exercise and cannot regain that same value
Glycogen synthesis is enhanced when in regarding to exercsie
after exercise – increased glycogen synthase activity
Why and when does CHO need to be consumed after exercsie
should be consumed immediately after exericse
* replenish muscle glycogen after exercise 2x as better immediately and continued higher values than compared to waiting to consume CHO
* 1-1.5 g/kg within 30 minutes
What type of foods are best to eat after exercise
high glycemic index foods are better –> ie. sports drink - something that breaks down easily
What should individuals consume in addition to CHO after exercise
protein
* reduces CHO need to resynthesise glycogen –decrease the number of CHO needed for CHO repleishment
* can co-transport CHO and protein to increase CHO uptake
* enhance muscle protein synthesis – recovery
What is the difference in glycogen synthesis amount in ingesting CHO immediately following exercise and then 2 hrs. after exercise
higher glycogen synthesis of eat right after
* difference is that if you eat immediately – glycogen synthesis is much higher from 1-120 min
- if you eat 2 hrs after exercise - similar results no matter when you eat from times of 120-240
What is the purpose of dietary fats
- fuel for energy
- hormone syntheis
- abosrption of fat-soluble vitamins
- cell membrane structure
- insulation
- protection of vital organs
Fats Proteins, Carbohydrates Are In Henry
Explain the overall facts of proteins
- not major soruce of energy: usually broken down in starvation and E deficit or very high intensity exercise
- high-quality proteins contain the nine essential AAs – cannot be synthesized in the body
need 0.8 g/kg per day - higher in athletes
What amount of water loss affects performance in the body
only 3-4% loss affects performance – dehydration
individuals intake water through what 3 ways
- beverages
- solid food
- metabolic processes – any time you breakdown glycogen
on average what is the common water loss per day
2500 mL per day (most in urine)
What is the adequate intake of water per day
- 2.7 L/day for women
- 3.7 L/day for men
How do different climates (dry or humid) effect water loss
in dryer climates –> lose more water compared to humid environments
What 4 places is water lost at rest
- insensible water loss from skin and respiration (not sweat)
- sweat loss
- urine
- fecal loss
What 2 places is water lost during exercise
sweating and insensible water loss (respiration)
explain how water is lost in sweat during exercise
* what is it dependent on and how much do we lose
- dependent on exercise intensity and environmental conditions
- water loss can be as high as 2.8 L per hr –> linked to core body temp
explain the difference between performance in someone who is hydrated vs. dehydrated
both are able to travel the same distance but the dehydrated individual will have a slower velocity
The goal is to have what type of hydration before exercise
to be euhydrated before exercise
* foods and bevreage consumed at meals should be sufficient
what are 3 things you can do if additional fluids are needed
- slowly drink beverages at least 4 hrs. prior
- drink more fluid if urine is dark or none is produced two hours prior
- sodium in beverages or slated snacks help retain fluid
What should fluid replacement look like during exercise
- want to reduce risk of excessive dehydration – hydrate during exercise
- important for both prolonged and intermittent exercise
if you are inside in the AC while it is HOT outside what will happen to your body and effect urine production
- vasoconstrict becasue your body is cold –> send blood volume towards to core –> excrete through urine
** best to drink H2O out in the hot so there is no vasoconstriction and therefore you decrease the urine output
fluid replacement during exercise is associated with what 3 things
- lower core body temperature
- lower HR
- lower RPE
cardiac drift is decreased with proper hydration
When should you water replace and what is this dependent on
dependent on duration and the individual
* events <1 hr – H2O only - enough glycogen stores
* events 1-3 hrs. – H2O + CHO + sodium b/c have sodium-glucose co-transporters in the stomach to increase absorbtion
* events >3hrs – H2O and CHO solution mixed with sodium
What is the goal during water replacement after exercise
replenish water, electrolytes and muscle glycogen
1.5 L fluid for every kg of weight loss – extra H2O
- CHO-electrolyte beverages or skim milk – ie. chocolate milk
What is the purpose and function of calcium
- provides bone and tooth strength
- helps blood clotting
- aids nerve impulse transmission = important for ACh release
- required for muscle contractions = Ca2+ bind to troponing (released from sarcoplasmic reticulum)
need 1000 mg/day
Why and how do you want to maintain calcium homeostasis
- bones are a “store” of calcium that helps maintain the plasma Ca2+ concnetration when dietary intake is adequate
What acts on bones to increase the release of Calcium during both intense and prolonged exercise
parathyroid hormone
explain the pathway of what happens with a rising blood Ca2+ level
- rising Ca2+ blood level
- thyroid gland releases calcitonin
- stimulates Ca2+ deposition in bones and reduces Ca2+ uptake in the kidneys
- Blood Ca2+ level declines to set point
explain the pathway of what happens with a falling blood Ca2+ level
- falling blood Ca2+ level
- parathyroid gland releases PTH
- stimulate Ca2+ release from bones +++ stimulate Ca2+ uptake in kidneys –> active vitamin D –> increases Ca2+ uptake in the intestines
- blood Ca2+ level rises to set point
if kidney uptake Ca2+ then active vitamin D goes to intestines increasing Ca2+ uptake in the intestines
What is the purpose of iron
- found in hemoglobin in RBCs which is involved in O2 transport to cells
- if dont have EPO –> no way to create hemoglobin –> cause hypoxia
iron makes up heme which makes up hemoglobin –> if less iron then less hemoglobin causing anemia –> anemia stimulates EPO to excrete more to create more RBC for O2 delivery
anemia is the deficiency in # of RBCs or decrase in amount of hemoglobin in the blood
What is the necessary amount of iron for males and females
- 8 mg/day for males
- 18 mg/day for females
need to suppliment
a deficiency in iron effects what two values
affects VO2max and endurance
* if cant build RBC doesnt matter the stimulus being given –> need materials to synthesize
why is an iron deficiency in athletes more common
- more common in females and distance runners
- increased intake and absorbption –> diets low in red meat, dieting for weight loss, vegetarian
- due to increaesd loss though sweat, fecies and urine
what can mask a true diagnosis of anemia
dehydration can mask diagnosis of anemia because overall hematocrit is lower
explain stage 1 vs stage 2 vs. stage 3 of iron deficiency
stage 1: depleted iron stores
* deficiency in iron-binding capacity
* lower serum ferritin – transport iron for EPO
stage 2: early functional iron deficiency
* transferrin saturation
* serum transferrin receptors (sTfR)
stage 3: deficiency in hemoglobin and mean cell volume (how lg. the RBCs are)
What are the restults to iron levels with iron supplementation
- increase iron intake through foods
- rapidly restores hematocrit and VO2max
What is the purpose of sodium in our bodies
- major ion of extracellular fluid == keep Na+(eighbors) out [extracellular] and the K+(ids) in
- directly involved in maintenance of resting membrane potential
- generation of an action potential in nerves and muscles == encourage/reduce changes of action potential
1500 mg/day
Who needs more salt in their diet
athletes require more salt than sedentary individuals
* b/c swating off a lot more H2O
* must repalce slat loss in sweat
If you are consuming a lot of water and urinating a lot frequently what does it mean to salt consumption needs?
you need to eat more salt
what is the best way to test salt/water replacement
testing body weight
* constant body weight indicates adequate salt and water intake
What are the fat soluble vitamins and where are they stored
A,D, E, K
* stored in adipose tissue
* excess intake can be toxic (toxicity)
What are the water soluble vitamins and what happens if you intake too much of them
- involved in energy metabolism
- B vitamins
- C vitamins – maintain bone, cartilage, and connective tissue
can pee out = cant absorb that much
When is supplementation needed for vitamins
- not necessary on well-balanced diets unless clear deficiency
- sm. athletes who consome low- E diets may have deficiency
no evidence for vitamin D supplementation == antioxidant (vit C and E) may interfere w/ muscle adaptations
What are the 5 purposes of precomptition meal
- provide adequate hydration
- provide CHO to “top off” liver glycogen stores
- avoid hunger feeling
- minimize GI tract issues
- allow stomach to be relatively empty at beginning of competition
What 6 types of body nutrients should be in precompetition meal
- fluid == maintain hydration
- mostly complex CHO == slower breakdown and limit simple sugars especially fructose
- low in fat and fiber = speed gastric emptying
- low in protein = takes more E to break down and contributes to acid in blood
- should be familiar foods
- liquid meal replacements can be used = smoothie/shake
how does a high fiber diet influence glycogen breakdown
breaks glycogen down slower throughout time
