Measurement of Energy Expenditure Flashcards
Direct Calorimetry measures what?
body heat production to estimate energy expenditure
What does Indirect Calorimetry measure?
Calculates energy expenditure from the ratio of CO2 produced to O2 Consumed
How can you measure Direct Calorimetry?
Air tight chamber: Expensive, measures temp changes
Doubly labeled water: But doesn’t tell you how many calories burned during exercise at rest
How do you measure Indirect Calorimetry?
Closed circuit: Container of air to supply O2 and absorb CO2
Open Circuit: Douglas bag, Metabolic cart (Did in lab)
Tells us fuel utilization
Respiratory Quotient
VCO2 Produced/ VO2 Consumed
Respiratory Quotient of a Carbohydrate
6 O2 produced for 6CO2 consumed: RQ= 1.00
Respiratory Quotient of Fat
16 CO2 produced for 23 O2 consumed: RQ= 0.70
Respiratory Quotient of Protein
63 Co2 Produced for 77 O2 consumed: RQ=0.82
** Note Protein makes up a low amount of energy/calorie expenditure because we use more in building muscle and stuff like that
Respiratory Quotient
RQ: Cell Level respiration
Respiratory Exchange Ratio
RER or R: Lung level Respiration
What are factors affecting Respiratory Exchange Ratio (R)
Hyperventilation: increased CO2 elimination
Lactic Acid buffering: Increased CO2 released
Decreased elimination of CO2 during recovery from exercise
What is Net Energy Expenditure
Gross Energy Expenditure - RMR
Amount of O2 needed to perform a given activity can vary between individuals
Economy (Mechanical efficiency)
3 Factors affecting performance
VO2 Max
Anaerobic Threshold
Economy (Mechanical efficiency)
Factors affecting economy of movement
- Training
- Muscle Fiber type
- Equipment
- Air Resistance
