Chapter 5 Flashcards
40% of substrate energy is converted into?
ATP
60% of substrate energy is converted to?
Heat
_____ production increases with energy production.
Heat
Heat production can be measured using which measuring device?
Calorimeter
What are the pros of direct calorimetry?
- Directly measures heat
- Accurate for total body energy expenditure over time
Indirect calorimetry is ____ and ______ compared to direct calorimetry.
Easier ; less expensive
Indirect calorimetry estimates total body energy expenditure based on ______ used, ______ produced during __________.
O2, CO2, oxidative phosphorylation
Why is it called indirect calorimetry?
Heat is measured indirectly
Indirect calorimetry is only accurate for __________ metabolism.
Steady-state oxidative
Volume of O2 consumed per minute (VO2) is considered as the rate of _________.
O2 consumption
Volume of CO2 produced per minute (VCO2), it is referred to as the rate of ___________.
CO2 production
What is the atmospheric air composition?
- Nitrogen: 79.03%
- Oxygen: 20.93%
- Other: 1.20%
- CO2: 0.03%
What is the fraction of O2 in inspired air?
0.2093
What is the fraction of CO2 in inspired air?
(0.0003)
What can indirect calorimetry determine?
Substrate utilization
What does O2 usage depend on?
Type of fuel being oxidized
Amount of _____ needed to oxidize a carbohydrate or a fat is proportional to _________ in that substrate.
O2 ; amount of carbon
More carbon atoms in molecule = ________
More O2 needed
Which compound needs more O2? Why?
Glucose: C6H12O6
Palmitic acid (C16H32O2)
Palmitic acid; because it has more carbons which requires more oxygen usage
What is the ratio between rates of CO2 production, O2 usage?
Respiratory exchange ratio (RER)
What is the RER equation?
RER = VCO2/VO2
What is the RER if there are 23O2 & 16 CO2?
0.70
At rest & modern diet, RER is equivalent to what?
0.80
T/F: CO2 production might not = CO2 exhalation.
True
What occurs during Hyperventilation?
Greater CO2 elimination
What occurs during Lactic acid buffering?
Greater non-metabolic CO2
T/F: RER near 1.0 will accurately predict fuel type.
False; it MIGHT not accurately predict fuel type
RER = __________________ / ____________
CO2 produced in metabolism ; O2 consumed
Respiratory Quotient = ___________ / ____________
CO2 eliminated ; O2 consumed
RER is ________ for protein oxidation.
Inaccurate
What does RER do to protein?
Ignores protein
Why is RER not used for protein?
Protein not completely oxidized
Based on that assumption that HR is linearly related to VO2, ________ can determine regression line for VO2:HR relation during submaximal exercise.
Heart Rate Monitoring
We can estimate ______ from ______ in other exercise settings.
VO2 ; HR
What does a pedometer measure?
Steps
What are some limitations of pedometers and accelerometers? (IDDL)
- Inaccurate step counts at slow speeds
- Differnt readings dependent on where they are worn
- Do not account for anthropometric differences
- Lack of calibration
What do accelerometers detect?
Acceleration which is translated to measurement of movement
What are the types of self-report methods?
- Activity questionnaires
- Physical activity records or diaries
What is the rate of energy used by the body?
Metabolic rate
What does knowing a persons VO2 let us estimate?
Caloric expenditure
What is the rate of energy expenditure at rest?
Basal metabolic rate
What are 3 requirements for measuring Basal metabolic rate?
- in supine position
- Thermoneutral environment
- After 8 h sleep and 12 h fasting
What does BMR reflect?
Minimum energy needed for living
BMR can also be affected by what? (Bsa,A,S,H,Bt)
- Body surface area
- age
- stress
- hormones
- body temperature
Resting metabolic rate is similar to what?
BMR
T/F: RMR requires stringent standardized conditions/
False
Athletes in intense training can be up to ________ kcal/day
10,000
Metabolic rate increases with _________.
Exercise intensity
What is our maximal O2 uptake referred as?
VO2 max
What is the best single measurement of aerobic fitness?
VO2max
VO2max improvement plateaus after _________ weeks of training.
8-12
More training allows athletes to to compete at _______________,
Higher percentage of VO2max
VO2 max is more common in ______. While VO2 peak is more common in ______.
Trained people ; untrained people
Sex difference in VO2 max is due to womens lower _________.
FFM and Hb
T/F: No activity 100% aerobic or anaerobic.
True
Estimates of anaerobic contribution to sustained exercise. (2)
- EPOC
- Lactate threshold
T/F: Exercise onset: O2 demand > O2 consumed
True
O2 deficit =
Difference between O2 required & O2 consumed
During exercise onset, the body incurs ______.
O2 deficit
ATP is generated through _______ pathways.
Anaerobic
T/F: Exercise end: O2 consumed < O2 demand.
False; it is the other way around
During exercise end, muscle activity is stopped but, _____________.
O2 consumption drops gradually
During exercise end, what goes into effect? (E)
Excess postexercise O2 consumption (EPOC)
What is the point at which blood lactate accumulation increases markedly?
Lactate threshold
What is usually expressed as percentage of VO2max?
T/F: Lactate production rate > lactate clearance rate.
True
Lactate can be used to oxidized type ____ fibers.
1
What is the possible reason that lactate production rate > lactate clearance rate?
Shift to anaerobic glycolysis
The greater the lactate threshold = ____________
Endurance performance
T/F: For two athletes with same VO2max, higher lactate threshold predict better performance
True
_______: LT at 50% - 60% VO2max
_______: LT at 70% - 80% VO2max
Untrained people
Elite end athletes
As athletes become more skilled, the use of less energy for given pace =
More economical
