2nd Midterm - Ch2, 3, 7 Flashcards
what is a diuretic
any substance that increases water loss
what percentage of water is intracellular
66%
what are 3 ways to lose water sensibly
feces
urine
sweat
what are 2 ways to lose water insensibly
breath
maintaining skin moisture
what hormone does alcohol inhibit that affects water loss
antidiuretic hormone (ADH)
what happens with the combination of hyponatremia and hyperhydration
low sodium and high water levels can overdilute blood plasma and cause cerebral edema
what is the primary consequence of disturbed fluid homeostasis
impaired thermoregulation
what rate does the stomach empty at
1-1.5L / h
heavy sweating causes loss of blood volume, what is this called
hypovalemia
how much does body temp rise per 1% body mass water loss
0.23 degrees celcius
what is normal body temperature range
36.5-37.5 degrees celcius
what temperature does hyperthermia start
38.3 degrees celcius
what is hyperpyrexia and at what temperature does it start
severe heat stroke
40 degrees celcius
3 symptoms of heat stroke
sweating, rapid breathing, fast weak pulse
how much water lost can lower V02max
3%
how long can minor dehydration (1-2%) be tolerated
90 minutes
how long can 3-5% water loss be tolerated if mainly using PCr system
30s
two elements most significant to water loss
sodium
chloride
when does fluid replacement with a sport drink become beneficial
activity over 2 hours long
is post exercise muscle cramping related to electrolyte loss?
no
how much bodily water must be present to store 500g of glycogen
2kg
what can be done as a hyperhydration strategy
glycerol loading
what is a tolerable % of CHO in sports drinks
6-8%
what is bioenergetics
study of energy transformation in living organisms
what’s the minimum % of bodily energy lost as heat
75%
what is direct calorimetry
direct measurement of heat energy
does macronutrient calorimetry provide a good measurement of caloric value
no, just an estimation
what does indirect calorimetry measure
oxygen and carbon dioxide gas exchange
what are the 3 components of total energy expenditure (TEE)
resting metabolism
thermic effect of food
physical activity
what is basal metabolic rate (BMR)
minimum energy required to keep body functioning at rest
what is the best time and position to measure basal metabolic rate
first thing in the morning, supine position
what is resting metabolic rate (RMR)
energy required to maintain non-active but alert state
how much more energy does RMR use than BMR
10%
5 factors of RMR not under voluntary control
sex
age
body size
hormones
genetics
how much does aging 10 years decrease RMR
1-2%
2 factors of RMR under partial control
fat free mass
fasting
how much does fasting decrease RMR
20%
5 factors of RMR under voluntary control
temperature
altitude
caffeine
nicotine
recent physical activity
how much does RMR increase at altitude
15-25%
how much does caffeine or nicotine increase RMR
3-7%
how long after intense exercise is RMR increased
90 mins
what are 3 equations used to estimate RMR
Mifflin-St. Jeor
Cunningham
Simplified RMR Formula
what is the disadvantage of using the mifflin-st. jeor equation
can underestimate RMR in athletes due to their low BMI
what variable needs to be knows to use the cunningham equation
fat free mass
what is the simplified RMR formula
0.9-1 kcal / kg / h = RMR
what is by far the most energy draining factor of TEE
resting metabolism
what % of caloric intake is spent on digesting the food
10%
what is the most variable factor of TEE
physical activity
what is 1 MET equal to
energy expenditure at RMR
how many METs is walking
3
how many METs is running stairs
15
how much ATP does the body contain
100 grams
how much ATP is hydrolyzed and regenerated each day
about a persons total body weight
how many times a day is an ATP molecule recycled
500-750
what is creatine excreted as, and roughly how much is excreted per day
creatinine, 2g
what percentage of creatine is phosphorylated in cells
66%
how much more cellular PCr is there than ATP
4-6x
how long does PCr system last
5-10 seconds
how much does cellular ATP drop during intense exercise
20-40%
how much does PCr deplete during intense exercise
over 80%
is muscle fatigue associated with ATP or PCr depletion
PCr
what % of ATP cannot be used for muscle contractions (to preserve basic RMR functions)
70-80% remains
how much can supplementation increase creatine concentrations by
20%
do all individuals react the same way to creatine supplementation
no, there is a high variability in response
what can be consumed alongside creatine to enhance uptake
carbohydrates
does increased creatine concentration make cells hyper or hypotonic
hypertonic, water rushes into cell
