LAB5- Resting Metabolic Rate Flashcards
total energy expenditure (TEE)
the amount of calroies (energy measured in kilocalories) burned by the human body in 1 day
what 3 categories is TEE divided into
-physical activity
-diet-induced thermogenesis
-resting energy expenditure
physical activity is what % of TEE
30%
physical activity aspect of TEE varies greatly depending onw hat
the client’s activity level
diet-induced thermogenesis
refers to the increase in energy expenditure that follows the ingestion of food
diet-induced thermogenesis is what % of TEE
10%
resting energy expenditure is what % of TEE
60%
determinants of physical activity in TEE
-intensity
-duration
-body weight
-genetics
determinants of diet-induced thermogenesis in TEE
-amount of food + composition
-hormones/SNS
determinants of resting energy expenditure in TEE
-body weight
-height
-fat free mass (SMM + OM)
-fat mass
-age
-gender
-hormones (thyroid, leptin, insulin, etc.)
-SNS
resting metabolic rate
the energy required to maintain physiological functions when the body is at complete rest
what unit is resting metabolic rate measured in
kilocalories
biological definition of resting metabolic rate
the amount of energy expended when an individual is awake, in a postabsorptive, thermoneutral state while having not exercised for typically 12hr
-not asleep because when sleeping your body becomes paralyzed + energy works differently
RMR is known at ___
REE (resting energy expenditure)
is RMR synonymous with basal metabolic rate
no
what energy does RMR include
energy used for breathing, heart contractions, organ functions, basic neurological functions, etc.
RMR is monitored in…
many chronic disorders + conditions
RMR is an extremely important value for who
clients that want to change their body composition
basal metabolic rate (BMR)
minimal energy expenditure for survival
-basic bodily functions, such as breathing, circulating blood + growing + repairing cells
-think survival, bare minimum
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BMR is measured after a ____ hour fast
14-18 hour
BMR requires that client abstained from exercise for at least ___ hours
24 hours
BMR is easy/difficult to measure clinically
difficult
resting metabolic rate (RMR)
distinction from BMR
similar to BMR but does not exclude all calories from digestion (thus the shorter fast) + does not have as strict of a protocol on restrictions from exercise before the measurement
RMR is measured after a ____ hour fast
4-8 hour
RMR requires client to have abstained from exercise for at least ____ hours
12 hours
RMR or BMR is always higher
RMR
RMR is ____% higher than BMR
10%
RMR/BMR is a better indicator of daily needs + what the body will use on a day-to-day basis
RMR
during sleep you are closer to RMR/BMR
BMR
factors affecting BMR
-lean body mass
-age
-gender
-body size
-genes
-ethnicity
-stress
-hormones
-starvation
-environmental temperature
-caffeine
-drugs
**what are the 2 biggest factors that affect BMR
-lean body mass
-body size
factors that affect BMR- lean body mass
the biggest factor in predicting metabolic rate
-muscle requires 6x the amount of energy that fat does to maintain
muscle requires ___x the amount of energy than fat does to maintain
6x more than fat
factors affecting BMR- body size
surface area is a large contributor to metabolism in endotherms
-at rest, radiation is the main method of dissipating heat
at rest, ____ is the main method of dissipating heat
radiation
5 methods of estimating RMR (via equations)
all of these are different for men vs women
-body surface area (BSA)
-Harris-Benedict equations
-fat-free mass (FFM)
-quick estimate in lbs BW
-quick estimate in kg BW
for BSA estimate equation, what do we use
nomogram
how to use nomogram to estimate BSA
-choose height
-choose weight
-draw a line + the middle nomogram intercept value is the BSA
2 ways metabolic rate is measured
-direct calorimetry
-indirect calorimetry
direct calorimetry
measures heat production
first direct calorimeter used on humans
Atwater-Rosa calorimeter created in 1897
indirect calorimetry
measures O2 consumption
the Atwater-Rosa calorimeter was compared to indirect calorimetry measurements gathered with what
an open circuit Pettenkofer system
-the 2 had extremely similar numbers
equation showing indirect vs direct calorimetry
food + O2 -> ATP + H20 + CO2 + heat
-O2 = indirect
-heat = direct
4 indirect calorimetry assumptions
- any fuel consumed has an intrinsic energy content that upon metabolic modifications in the living system will result in heat or energy production
- the combination or synthesis of carbohydrate, fat, or protein is the end result of all the biochemical reactions occurring in the body
- the oxidation of glucose, fat, or protein results in a substance-specific ratio between the quantities of O2 consumed + CO2 produced
- loss of substrates is negligible in feces + urine
why are small errors made in indirect calorimetry
because of the metabolism of minerals is not accounted for in the second assumption + that fat + protein don’t have uniform properties which slightly affect the accuracy of assumption 3 (aka the oxidation of glucose, fat, or protein reuslts in a substance-specific ratio between the quantiteis of O2 consumed + CO2 produced)
regardless of the macronutrient used, with every liter of oxygen consumed by the body, ____ kcal are burned
5 kcal
protocol to measure RMR using indirect calorimetry
- ensure the metabolic cart is in a quiet, dim location where the client can relax
- explain the procedure to the client + properly fit them with the mask
- have the client lay down in a comfortable position on their back
- instruct the client to remain as still as possible for the remainder of the test + to avoid falling asleep
- turn the lights down, begin data collection with the metabolic cart
- the subject will lay still for 15-20 minutes
- at the end of that time, stop the metabolic cart + take the client’s mark off
- the client’s RMR will be an average of the lowest minute of VO2 values shown during the test
- take the relative RMR + convert into calories per day
ACSM metabolic equations
often when prescribing exercise, there won’t be any indirect calorimetry values to base the prescription
-in these situations trainers + physiologists can use the ACSM metabolic equations to estimate calorie expenditure or VO2
ACSM metabolic equations are used to estimate what
the VO2/calories of some frequently used modes of exercises: running, walking, stair stepping, cycle ergometry and arm ergometry
when were the ACSM equations calculated
1960s
-but remain relatively accurate
who created the ACSM walking equation
DB Dill
-famous physiologist + founding director of Harvard Fatigue Lab
helpful reminders for ACSM calculation
-remember order of operations from algebra (PEMDAS- parentheses, exponents, multiplication + division (from left to right), addition + subtraction (from left to right)
-make sure to have the correct units for each variable; if you’re not in the correct units, then convert
-with all your answers ask if they’re logical; for instance, if you are calculating calories for a workout + your answer is 2.532 kcals, it doesn’t make sense + there must be a mistake in the calculations
ACSM calculations- the answers should be in relative/absolute VO2
RELATIVE
ACSM calculations- if you calculate a value for exercising VO2 that’s not between ____ mL/kg/min and ____ mL/kg/min you did something wrong
10-75 mL/kg/min
**energy equivalency flowchart
KNOW how to go forwards/backwards
METS -> x3.5
relative VO2 (mL/kg/min) -> x [BW (kg) / 1000]
absolute VO2 (L/min) -> x5
kcal/min -> x total # minutes
total kcal
units for relative VO2
mL/kg/min
units for absolute VO2
L/min
