Chapter 5 Flashcards
What calculates energy expenditure from the ratio of CO2 produced to O2 consumed
Indirect calorimetry
What measures the body’s heat production to estimate energy expenditure
Direct calorimetry
What is the rate of O2 and CO2 exchanged in the lungs=rate of use and release by the body tissues
Oxygen consumption (VO2)
What method is used to measure oxygen consumption (VO2)
Indirect calorimetry
What is the single best measurement of cardiorespiratory endurance and aerobic fitness
VO2 max
The higher the ________, the higher the fitness level
VO2 max
What is VO2
The volume of oxygen consumed per minute
What is VCO2
The volume of carbon dioxide produced per minute
What are the three gases that make up inspired air
Oxygen
Carbon dioxide
Nitrogen
Oxygen:
Carbon dioxide:
Nitrogen:
- 93
- 04
- 03
What is a mathematical formula formula that allows us to calculate VI from VE because nitrogen concentration remain constant
The Haldane transformation
In what is the ratio between CO2 released (VCO2) and oxygen consumed (VO2)
respiratory exchange rate (RER)
RER= ____/_____
VCO2/ VO2
RER provides us data that reveals what primary ________ our body is using for energy production
Substrate
The RER value at rest is usually what
.80
RER oxidation of fat is what
.70
RER oxidation of carbohydrate is what
1.0
RMR is the minimum amount of energy required by the body to sustain basic _______ function
Cellular
Depending on the individual, RMR ranges from __________kcal/day
1100 to 2500
When activity is added, RMR’s daily caloric expenditure is __________ kcal/day or higher
1700-3100
What factors affect RMR
Age Body temperature Psychological stress Hormone Injury
RMR gradually decreases with what
Age
RMR increases with increasing what
Temperature
What hormones increase RMR
Thyroxine and epinephrine
When the body is healing from an injury RMR _______
Increases
During exercise at a constant power output (work rate) VO2 increases from it’s resting value to a steady state value within __ to ___ minutes
2 to 3
Metabolic rate during sub maximal exercise, increases in metabolism and VO2 are ______ with increases in work rate (exercise intensity)
Proportional
VO2 max is the maximal capacity for _____ consumption by the body during _____ exertion
Oxygen
Maximal
VO2 max is expressed relative to what
Body weight
What are the highest VO2 max values for male and female
Male: 94
Female: 77
VO2 max declines after what ages
25-30 1% per year
What is the difference between the O2 required for a given exercise intensity and the actual O2 consumption
Oxygen deficit
In anaerobic capacity there is ___ ______ acceptance method to determine ones ______ anaerobic capacity
No clear
True
Anaerobic capacity can only be _______
Estimated
What’s is the anaerobic effort estimated by the elevated O2 consumption after an exercise bout had ended
Excess post exercise oxygen consumption (EPOC)
A factor responsible for EPOC is rebuilding depleted ______ supplies
ATP/PCr
What is the point at which blood lactate begins to accumulate (exceeding lactate clearance) during intense exercise
Lactate threshold
The lactate threshold denotes a shift in energy systems from ______ to _______
O2
Anaerobic
Lactate threshold is expressed as a ____ of VO2 max
%
In lactate threshold H+ accumulation contributes to ______ (the ______)
Fatigue
Wall
What is one of the best determinants of an athletes pace in endurance events
Lactate threshold
Untrained people have LT around __% to ___% of their VO2 max
50
60
Elite athletes may not reach LT until around ___% to ____% VO2 max
70
80
What are the characteristics of successful endurance athletes
- High VO2 max
- Lactate threshold
- Economy of effort
- High % of type 1 fibers
Causes of fatigue:
1. _______ depletion. (Diet)
Energy
Causes of fatigue:
2. Accumulation of ____ which decreases_____
H+
pH
Causes of fatigue:
3. Failure of the muscle fibers _______ mechanism
Contractile
Causes of fatigue:
4. Muscle fiber _____
Type
Causes of fatigue:
5: alterations in the _______ system
Nervous
Causes of fatigue:
6. ______ level
Fitness
Cells buffer H+ as lactate with bicarbonate to keep cell pH between _____ (at exhaustion) and _______
- 4
7. 1
Intercellular pH lower than 6.9, however, slows ______ and _____ production
Glycolysis
ATP
When pH reaches 6.6 to 6.4, H+ levels ____ glycolysis and the result is ______
Inhibit
Exhaustion
The primary cause of fatigue during maximal, all out exercise lasting more than 30 seconds is ___ _____ ______
Low muscle pH
