Energy expenditure Flashcards
indirect calorimetry
don’t measure heat, measures O2, CO2 and N
*inhale air with known composition and then monitor changes
Respiratory Quotient
- useful to tell which foods and energy sources
RQ = CO2 produced/ O2 consumed
RQ of carbs__
RQ of fat __
RQ of protein __
1
.7
.82
Total daily energy expenditure
resting metabolic rate: 60-75%
heat production - 10%
energy expended in activity 15-30%
BMR
the amount of energy that your body uses to fuel cellular activity at rest
Measuring BMR
gold standard: measure persons O2 uptake at rest NPO x 12 hrs * no exercise x 12 hrs before test lie still for 30-60 mins measure O2 and CO2
BSA - body surface area
the larger the surface area, the more energy you need to expend to maintain body temp
BMR x BSA x 24 hrs =
basal metabolic rate) x (body surface area
resting daily EE
BMR x BSA x 24 hours = calories needed per day
women have a __% lower metabloc rate
5-10
* also have larger % body fat, smaller muscle mass and smaller body surface
Does BMR increase or decrease with age?
decrease
if you increase % body fat what happens to LBM
decreases
expenditure with activity
gross energy expenditure = O2 consumed x duration of activity *convert to calories 45 minutes x 2L of O2 = 90 (1L O2 = 5kcal ) 90 x 5 = 450 kcal
1L of O2 = __kcal
5
BSA x BMR =
resting horly energy expenditure
Net energy expenditure =
exercise energy - BMR
30 yr old male exercises for 45 mins. height= 185 cm. BM = 75kg. Energy expenditure is 450 kcal. BSA = 2.05. How many calories did he burn with exercise alone?
- (BSA x BMR) = (2.05 x 36.8) = 75.4 kCal/hour
- 75.4 kCal / 60 min x 45 min = 56.58 k Cal from activity
- net energy = exercise energy - REE
450 - 56.58 = 393.44 kcal
net energy = 393.4 in 45 mins
endurance exerrcises depend on
VO2 max
lung function
genetics 30-30%
ME
mechanical efficiency = % of total enerfy expended that contributes to work ME = work output/ energy input x 100 W = (FxD) *more efficient, less O2 consumed most activities are 20-25% efficient
which muscle fibers are more efficient
type 1
if higher level of fitness __ level of energy expenditure
lower
increased BMI = __ energy expenditure
higher
becomes inefficient to keep walking at ___mph
4.8
The heavier you are,
the more energy you expend with activity
W= F x D
What happens when walking with weights
increase in SBP
