Energy Expenditure Flashcards
almost all changes that occur in the body during exercise are related to the increases in
energy metabolism occurring with contracting skeletal muscle.
1t rest a 70kg human has an expenditure of about___.
how much is used by skeletal muscle?
1.2Kcal/min
less than 20%
during intense exercise total energy expenditure may be ___ times that of resting value.
what is the caloric expenditure?
15-25x
18-30 Kcal/min
Why does energy expidenture increase during intense exercise?
to provide E for exercising muscles which can increase by factor of 200 compared to resting levels.
involves all of the chemical reactions of biomolecules within the body that encompass both synthesis (anabolism) and breakdown (catabolism)
metabolism.
all processes occurring in the body result in production of
heat.
Amount of E generated by body during rest and exercise can be determined by
direct or indirect calorimetry
reflects the body’s heat production, it is the minimum level of energy to sustain vital functions in the waking state
Basal metabolic rate.
knowledge of the BMR establishes the important energy baseline for constructing a sound program of
weight control through food restriction and exercise
how much lower is BMR in females than males?
why?
5-10% lower.
higher body fat and fat is less metabolically active than muscle.
What is BMR influenced by?
age gender surface area of body body fat thyroid Fx protein turnover nutrition ANS temp fever
What is main factor governing BMR?
amt of lean body mass
Why does BMR decrease through adulthood?
increase in fat.
decrease by 2 %
if caloric intake less than BMR, this will decrease
exercise tolerance.
refers to the sum of the metabolic processes of the active cell mass related to the maintenance of normal, body functions and regulatory balance during rest
what does it include?
Resting metabolic rate
BMR
sleeping conditions
What is total Daily Energy expenditure influenced by?
RMR
Thermal effect of feeding
Physical activity and recovery.
What has most profound effect on Energy Expenditure?
Physical activity 15-30% of it.
sustained metabolic rate compared to resting values during big muscle exercise?
10 times more.
What can physical activity be broken down into?
Non-exercise activity thermogenesis (NEAT) aka ADLs
how long can metabolic rate stay elevated after strenuous aerobic exercise?
8 hours.
E expended during weight-bearing activities increases
proportional to body mass
little relationship w/ NWB activities.
Relationship between walking speed and 02 uptake essentially linear between speeds of
1.9-3.1
what influence EE of particular activities?
economy of movement
mechanical efficiency.
Children require how much more oxygen per unit of body mass to run compared to adult?
20-30%.
whats more economical at higher speed? walk or jog?
jog.
swimming increases EE compared to running by
4 times.
Diet-Induced Thermogenesis consists of what 2 components?
Obligatory and
Facultative
a result of the energy-requiring process of digesting, absorbing, and assimilating food nutrients
Obligatory DIT
related to the activation of the SNS and its stimulating effect on metabolism
Facultative DIT
Thermic effect of food reaches max within
what does the magnitude of DIT vary between?
1 hour after meal.
10-30% of ingested food.
Thermic effect of protein is ___
why
25% of meals total calories.
extra energy by liver to break it down.
What are situations of decreased thermic response?
poor control of body mass (leads to more fat)
exercise trained ppl.
Eating augments ___
DIT..
eat then exercise.x2 thermic effect.
RMR of people in tropics is
5-20% higher.
what does exercise in heat do?
increases MET load causing increase in VO2 by 5%
cold increases what?
metabolic rate of shivering at rest?
energy metabolism
shivering increase metabolic rate 5 fold
increased maternal body mass of pregnancy adversely effects:
exercise economy.
CV dynamics normal.
E produced through metabolism of food is equal to
heat produced by body
DIRECT CALORIMETRY
an airtight, thermally insulated living chamber
Calorimeter
not good for sports.
in direct calorimetry,
each increase in H20 temp of 1 degree C per kilogram of H20 is equal to
1 Kcal of energy
involves the measurement of oxygen consumption- V02 – the quantitatively measured maximum capacity for the aerobic resynthesis of ATP
Indirect Calorimetry.
5.0Kcal per liter of oxygen consumed is an appropriate conversion factor to estimate
EE under steady-rate conditions of aerobic metabolism.
EE can be expressed in
VO2
MET
Kcal
a measure of activity intensity and represents an average person’s resting metabolism or V02
MET
1 MET=
3.5 ml.kg.min
or
1Kcal/kg/hour
Classification of EE?
<3MET= light
3-6 MET = mod
>6 MET= Vigorous
ADLs require how many METS?
level of intensities to promote health and fitness?
3-5 METS
mod-vigorous.
do METs apply to kids?
naw.
VO2 can be expressed in
L/min=absolute
ml.kg/min= relative
METS
Kcal= 5 Kcal/L of O2 consumed.
Measurement tools include:
6MWT
HR
RPE
RR
REP of 11-16
13-16
18-19
11-16= 50-75% VO2 max 13-16= Ventilatory threshold 18-19= cause fatigue.
