Chapter 7 - Energy Transfer During Physical Activity Flashcards

1
Q

What is the ATP-PCr Energy System Responsible for?

A

High-Intensity Exercise of Short Duration
- Under 10 seconds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How much ATP and PCr does each kg of skeletal muscle contain?

A

ATP
- 3-8mmol
PCr
- 12-48mmol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the Short-term Glycolytic Energy System responsible for?

A

Intense, Short-duration exercise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What results from short-term glycolytic energy systems?

A
  • lactate formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

When would there be rapid and large accumulation of blood lactate?

A

Maximal Exercise of 60-180 seconds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What happens when you decrease intensity of exercise to extend duration?

A
  • Depressed lactate accumulation rate
  • Reduced final blood lactate levels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Does blood lactate accumulate at all exercise levels?

A
  • NO
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

When does blood lactate not accumulate during exercise?

A

Light/Moderate Exercise
- Under 50% aerobic capacity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why does blood lactate not accumulate during light/moderate exercise?

A
  • Lactate production equals lactate clearance
  • Oxygen-consuming reactions adequately meeting exercise energy demands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What have tracer studies that label the carbon in glucose show about lactate?

A
  • 70% oxidizes
  • 20% converts to glucose in muscle/liver
  • 10% synthesizes amino acids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why would a trained person perform steady-rate aerobic exercise at 80-90% of maximum aerobic capacity?

A
  • Specific Genetic Endowment
  • Specific local training adaptations that favour less lactate production
  • More rapid rate of lactate removal at any exercise intensity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the difference between lactate concentration for trained and untrained individuals?

A

Untrained
- Early lactate threshold
- Lower max lactate tolerance
Trained
- Steep curve
- Later lactate threshold
- High tolerance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which factors are related to the lactate threshold?

A
  • Low tissue oxygen
  • Reliance on Glycolysis
  • Activate fast-twitch muscle fibers
  • Reduced lactate removal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What factors contribute to higher blood lactate levels during maximal exercise due to specific sprint-power anaerobic training? Are these factors permanent?

A

Factors
- Improved motivation
- Increased intramuscular glycogen stores
- Increase in Glycolytic-Related Enzymes
-not permanent and decreases when training ceases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does lactate shuttling between cells do?

A
  • enables glycogenolysis in one cell to supply other cells with fuel for oxidation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Other than lactate production, what is the muscle also a major site for?

A
  • Removal of lactate via oxidation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What happens to glucose that is derived from lactate?

A
  • Returns in blood to skeletal muscle for energy metabolism
  • Synthesizes to glycogen for storage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the long-term energy system?

A
  • The Aerobic System
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When does aerobic metabolism provide nearly all the energy transfer

A

when intense exercise continues beyond several minutes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What happens with oxygen uptake during exercise?

A

Initially
- Rises exponentially
Eventually
- Plateaus, then remains in steady-rate for duration of effort

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Explain steady-rate aerobic metabolism

A
  • balance between energy required and ATP production in aerobic reactions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What happens to lactate during steady-rate conditions?

A
  • No appreciable blood lactate accumulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Steady-rate aerobic metabolism could progress indefinitely. However, what 2 factors limit how long you can sustain steady-rate metabolism?

A
  • fluid loss/electrolyte depletion
  • depletion of glycogen reserves in liver for CNS and muscle to power exercise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

flagged for redundancy

What two factors help explain athlete’s high steady-rate levels?

A
  • High capacity for oxygen delivery to working muscles (central circulation)
  • High capacity of active muscles to use oxygen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Describe the oxygen deficit?

A
  • the difference between total oxygen consumed and total that would be consumed with immediate steady-rate uptake
26
Q

What does the Oxygen Deficit represent?

A
  • immediate anaerobic energy transfer from the hydrolysis of intramuscular high-energy phosphates and glycolysis until steady-rate energy transfer meets current energy demands
27
Q

How does the energy for exercise occur?

A
  • smooth blending and considerable overlap of different modes of energy systems
28
Q

What is the oxygen uptake fast component?

A
  • Exponential rise in oxygen uptake in first minutes of physical activity
  • reaches a plateau after at around 3rd or 4th minute
29
Q

What is unique about endurance-trained individuals regarding steady-rate?

A

Compared to sprint-power athletes, cardiac patients, older adults, and untrained:
- Reach it more rapidly
- Smaller oxygen deficit

30
Q

What causes a trained individual to consume a greater total amount of oxygen during steady-rate exercise? What else does it do?

A

Faster Aerobic Kinetic Response
- makes an anaerobic component of exercise energy transfer proportionally smaller

31
Q

What three aerobic training adaptations facilitate the rate of aerobic metabolism when exercise begins?

A
  • Rapid increases in muscle bioenergetics
  • Rapid Increase in overall blood flow
  • Disproportionally larger regional blood flow to active muscle, complimented by cellular adaptations
32
Q

What do the three aerobic training adaptations that facilitate the rate of aerobic metabolism when exercise begins do?

A
  • Increase individual total capacity to generate ATP aerobically
33
Q

when does VO2max occur?

A

when oxygen uptake plateaus or increases only slightly with additional exercise intensity

34
Q

What does a High VO2max require?

A

Integration and high-level responses of:
1. Pulmonary Ventilation
2. Hemoglobin Concentration
3. Blood Volume and Cardiac Output
4. Peripheral Blood Flow
5. Aerobic Metabolism

35
Q

What four factors does Hill suggest that determine VO2max?

A
  • Arterial O2 Saturation
  • Mixed Venous Saturation
  • O2 capacity of the Blood
  • Circulation Rate
36
Q

What quantitative estimate is made for arterial O2 saturation?

A
  • Ventilation
    Hill noticed no cyanosis, and assumed that the lungs oxygenated the blood well enough
37
Q

What quantitative estimate is made for Mixed Venous Saturation?

A
  • Central Blood Flow
38
Q

What quantitative estimate is made for O2 capacity of the blood?

A
  • Active Muscle Metabolism
39
Q

Which quantitative estimate is made for the circulation rate?

A
  • Peripheral Blood Flow
40
Q

Why are athletics used for study on exercise physiology?

A
  • Simple, measurable, and constant
  • Athletes: reduced danger (healthy)
  • Exciting and new for physiology (more recruits)
41
Q

Why are both muscle twitch fibers usually required for most sports?

A
  • slow, sustained muscle action
  • Short bursts of power
42
Q

What do athletes who excel in different sports usually have with regard to muscle fiber type?

A
  • a large percentage of specific muscle fiber type that supports that sport’s energy demand
43
Q

Describe Fast-Twitch Muscle Fibers

A

Type II
- Rapid Contraction Speed
- High Capacity for Anaerobic ATP production
Type IIa
- High Aerobic Capacity

44
Q

Describe Slow-twitch muscle fibers

A
  • Generate energy through aerobic pathways
  • Slow contraction speed
45
Q

What type and percentage of muscle fibers would a swim champion have?

A

Type II
- Fast-twitch
- 80%

46
Q

What type and percentage of muscle fibers would an endurance cyclist have?

A

Type I
- Slow-twitch
- 80%

47
Q

What is EPOC?

A

Excess Post-exercise Oxygen Consumption

48
Q

Which 7 things contribute to EPOC?

A
  • Resynthesize ATP & PCr
  • Resynthesize Lactate to Glycogen
  • Oxidize Lactate for energy metabolism
  • Restore Oxygen to Myoglobin and Blood
  • Restore thermogenic effects of elevated core temp
  • Thermogenic effect of hormones (catecholamines)
  • Restore Elevated HR, VE, other physio function
49
Q

What happens during recovery from steady-state exercise?

A
  • Re-synthesis of high-energy phosphates
  • replenish O2 in blood
  • Replenish bodily fluids
  • replenish muscle myoglobin
  • small energy cost to elevate circulation/ventilation
50
Q

Why is passive procedure important during recovery from steady state exercise?

A
  • additional exercise elevates total metabolism, delay recovery
51
Q

What do most individuals do when left to their own choice regarding steady-state exercise?

A
  • Select optimal recovery intensity
52
Q

What does performing aerobic exercise in recovery do to lactate?

A
  • Accelerates blood lactate removal
53
Q

Why does performing aerobic exercise in recovery from non-steady state exercise accelerate blood lactate removal?

A

Increased
- blood perfusion through the liver, heart, and ventilatory muscles
- blood flow through skeletal muscles in active recovery

54
Q

Describe Intermittent Interval Physical Activity

A
  • Supramaximal exercise to overload specific energy transfer system
  • Rapid recovery in interval
55
Q

What can you do in interval training to overload a specific energy-transfer system?

A
  • Manipulate duration of exercise and rest intervals
56
Q

define blood lactate threshold

A

when muscle cells can
neither meet energy demands aerobically nor oxidize lactate at its rate of formation

57
Q

what affects blood lactate independent of oxygen consumption

A

muscle fiber type used

58
Q

what kind of information does VO2max provide?

A
  • It provides a quantitative measure of a person’s capacity for sustained aerobic ATP re-synthesis
  • Indicates ability to maintain intense exercise for longer
    than 4 to 5 minutes
59
Q

describe type 1 muscle fibers

A
  • Generates energy through aerobic pathways.
  • Slower contraction speed than fast-twitch fibers.
  • Active in continuous activities requiring steady-rate aerobic
    energy transfer
60
Q

define lactate threshold

A

when muscle cells can neither meet energy demands aerobically nor oxidize lactate at its rate of formation