Term
| How do we measure energy metabolism? |
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Definition
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Term
| What are the two ways that VO2 is measured? |
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Definition
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Term
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Definition
the actual amount
expressed in liters per minute |
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Term
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Definition
the VO2 relative to body weight of an individual
expressed in ml per kg per minute |
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Term
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Definition
| how much oxygen your body consumes every minute |
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Term
| What is your relative VO2 if you weight 100kg and your absolute VO2 is 5L/min? |
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Definition
50 mL/kg/min
5L = 5000mL
5000/100 = 50 |
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Term
At rest:
(A)what system primarily make ATP?
(B)what are blood lactate levels?
(C)what is resting relative and absolute VO2? |
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Definition
(A) almost 100% by aerobic systems
(B) less than 1 mM/L
C) 0.25L/min and 3.5 mL/kg/min |
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Term
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Definition
metabolic equivalents
the expression of energy cost for activities in a simple unit |
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Term
| What is one MET equal to at rest? |
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Definition
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Term
What is VO2 max?
How do we measure VO2 max? |
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Definition
the maximal rate to transport and use oxygen
subject must reach exhaustion |
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Term
| Explain a VO2 max test using a treadmill. |
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Definition
increase speed until the subject reached 80% of their max heart rate (APMHR).
begin increasing incline 2% every minute until subject reaches exhaustion. |
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Term
| What is the five criteria for addressing a VO2 max? |
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Definition
1) the plateau in oxygen consumption
2) the attainment of RER=1-1.5 <
3) the attainment of APMHR (220-age)
4) the exhaustion of the subject
5) blood lactate level of 8 mM/L |
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Term
| What are the two sources of CO2? |
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Definition
metabolism (carb and fat)
hydrogen buffering system |
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Term
| Explain the transition from rest to exercise. |
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Definition
-ATP production increases immediately
-oxygen uptake increases rapidly
-initial ATP production made through anaerobic pathways
-oxygen deficit |
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Term
How long does it take to reach a steady state?
How is ATP made after steady state is reached? |
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Definition
1-4 minutes
aerobic systems |
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Term
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Definition
lag in oxygen consumption at the onset of exercise
the difference between the TOTAL OXYGEN ACTUALLY CONSUMED during exercise and the TOTAL OXYGEN REQUIRED (CONSUMED) in steady-rate from start of exercise |
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Term
How is oxygen supplied at the onset of exercise?
What are the consequences? |
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Definition
maintained through oxygen stores
ATP-PCr systems
fast glycolysis
the more oxygen borrowed means more recovery time
lactate concentration will be greater the more oxygen borrowed |
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Term
| Explain oxygen deficit in trained individuals. |
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Definition
have a lower oxygen deficit
they reach a steady state quicker, using less anaerobic systems, producing less lactic acid which means shorter recovery |
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Term
| what is the difference between submax and max testing? |
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Definition
| with submax testing the subject will be able to reach steady state |
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Term
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Definition
excess postexercise oxygen consumption
after exercise, oxygen consumption doesn't return to resting levels immediately
aka oxygen debt |
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Term
| What happens in the body during the fast curve component? |
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Definition
steep decline in oxygen consumption
replenish ATP, PCr, and oxygen stores to 100% |
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Term
| What happens in the body during the slow curve component? |
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Definition
slow decline in oxygen consumption
elevated HR, breathing, body temp, epinephrine and norepinephrine
conversion of lactic acid to glucose**gluconeogenesis
aka lactate acid phase |
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Term
| explain why EPOC is greater after high intensity exercise. |
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Definition
higher body temp
greater depletion of PC
greater blood lactate concentrations
higher blood epinephrine/ norepinephrine levels |
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Term
| What happens to lactate during recovery? |
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Definition
70% oxidized by non working muscle cells
20% reconverted to glucose
10% converted to amino acids |
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Term
| what is the metabolic response to prolonged exercise? |
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Definition
ATP production primarily from aerobic systems
steady state oxygen uptake can generally be maintained during submax exercise |
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Term
| what is the metabolic response to prolonged exercise in a hot and humid environment or at high intensity? |
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Definition
upward drift of oxygen uptake over time due to the increase in body temp and rising epinephrine/ norepinephrine levels
a steady state will not be reached |
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Term
What is the lactate threshold?
what is it also known as? |
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Definition
the point at which blood lactic acid rises systematically during incremental exercise
anaerobic threshold
onset of blood lactate accumulation (OBLA) |
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Term
| what is bicarbonate buffering? |
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Definition
non-metabolic CO2 production
helps regulate lactic acid concentrations to delay reaching lactate threshold |
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Term
| What are the four explanations for the lactate threshold? |
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Definition
1) low muscle oxygen (hypoxia)
2) accelerated glycolysis: NADH is produced faster than it can be moved to the mitochondria, changes pyruvate into lactic acid
3) recruitment of fast-twitch muscle fibers: contains LDH isozyme
4) reduced rate of lactate removal from the blodd |
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Term
| what is the most common LDH isozyme in muscles? |
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Definition
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Term
| what are the practical uses for lactate threshold? |
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Definition
prediction of performance
planning training programs |
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Term
| how many kcal's does 1L of oxygen equal? |
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Definition
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Term
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Definition
respiratory exchange ratio
an estimate of the primary substrate bring used to make ATP
CO2/ O2 |
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Term
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Definition
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Term
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Definition
the type of fuel being used by the cell
fat = 0.7 RER
carbs = 1 RER |
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Term
| how can we use RER to estimate energy expenditure? |
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Definition
| must reach a steady state by sumaximal exercise |
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Term
| what is the RER of an trained and untrained individual? |
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Definition
trained = 1.5-2.0
untrained = 1.01-1.08 |
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Term
| explain protein metabolism during prolonged exercise. |
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Definition
proteases breakdown protein and may contribute to as much as 5-10% of energy.
12-15% during max effort
proteins play a more important role is providing the enzymes to drive the reactions.
urea is a byproduct |
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Term
| using R value to find kcals. |
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Definition
estimation of kcals expended, just add 4
can only be done if steady state is reached |
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Term
example of using RER to find calories:
2.5L/min for 10 minutes with a RER of 0.8, how many calories are expended? |
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Definition
2.5x10=25
4+0.8=4.8
4.8x25=120kcals in ten minutes |
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Term
| what is the primary fuel of low intensity exercise(<30% VO2 max)? |
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Definition
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Term
| what is the primary fuel of high intensity exercise (>70% VO2 max)? |
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Definition
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Term
| explain the crossover concept? |
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Definition
| describes the shift from fat to carbs as exercise intensity increases |
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Term
| what causes the crossover? |
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Definition
recruitment of fast-twitch muscle fibers causes an increase in glycolytic enzymes
increasing blood levels of epinephrine/ norepinephrine which causes phosphorylase to breakdown glycogen |
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Term
what is the fuel for low intensity, prolonged exercise?
why? |
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Definition
shift from carb to fat metabolism
due to the increased rate of lipolysis by lipases activated by epinephrine/ norepinephrine, recruitment of slow-twitch muscle fibers, and aerobic metabolism |
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Term
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Definition
| primary source of carbs during high intensity exercise during the first hour of exercise |
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Term
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Definition
formed in the liver by gluconeogenesis
primary source during low intensity exercise
important during long-duration exercise |
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Term
| discuss intramuscular triglycerides. |
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Definition
| primary source of fat during high-intensity exercise |
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Term
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Definition
formed from adipose lipolysis
FFA converted to acetyl-CoA to be used in the Krebs Cycle
primary source of fat during low-intensity exercise
important as muscle triglycerides decline |
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Term
| how is protein supplied during exercise? |
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Definition
| broke down into amino acids and can be converted to glucose in the liver. about 2% of total energy |
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