Aerobic Fitness and Performance (year 2) Flashcards

1
Q

What is Aerobic Fitness?

A

• The capacity to sustain a given speed or work rate
for the longest possible time

• For exercise longer than 120s, the majority of
energy is derived through oxidative metabolism

• Requires O2
to be delivered to the mitochondria,
sufficient availability of fuels and appropriate
oxidative capacity within the mitochondria

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2
Q

What are the Parameters of Aerobic Fitness?

A
  • Maximal Oxygen Uptake
  • Maximum rate that the body can consume oxygen
  • Running Economy
  • How much oxygen it costs to run a certain speed
  • The fractional utilization of maximal oxygen uptake
  • Linked to the lactate accumulation in muscles and blood
  • Oxygen Uptake kinetics
  • The rate at which oxygen uptake rises when we start exercising
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3
Q

what is Maximal Oxygen Uptake?

A
  • Integrated capacity of pulmonary, cardiovascular and muscular systems
  • Highest O2 uptake despite further increases in work rate/exercise intensity
  • Reflects uptake, transport and utilisation of O2
  • Criterion measure of:
  • Intervention efficacy
  • Environmental impact
  • Disease prognosis
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4
Q

Verifying a VO2 Max

A

• Leveling off in VO2 despite increasing work rate: <150 ml∙min–1 or <2.1 ml∙kg–1
∙min–1

• Secondary criteria:
• Post-exercise blood lactate >8 mmol∙L
–1
• R >1.15
• HR within 10 beats∙min–1 of age-predicted maximal HR
• RPE ≥ 18
• Should not expect participants to meet all criteria

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5
Q

what are the determinants of VO2 Max?

A

Oxygen Utilisation–>Peak VO2=cardiac output (Q)(O2 Delivery)x aterio-venous O2 difference(O2 Extraction)

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6
Q

Effects of Training on VO2 Max?

A

• 15-30% increase in VO2max with endurance training in adults

  • Effect of resistance training less clear
  • 3/17 studies in young adults show positive effect
  • 6/9 in older adults in older adults show positive effect

• Effect of HIIT equal to, or greater than, endurance
training

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7
Q

VO2 Max and Performance: Limited practical applicability?

A
  • Can’t distinguish between performances – limited adaptability in elite athletes
  • Can’t design optimal training programmes
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8
Q

what is Lactate threshold:

A
  • The point at which blood lactate concentration first begins to increase systematically and consistently
  • Some labs use a blood lactate concentration of 2mmol·l-1 but direct identification of first breakpoint in lactate curve preferable
  • Mechanisms of fatigue may differ above and below the lactate threshold
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9
Q

Lactate Threshold and Performance:

A

• Typically 50-60% VO2max in healthy, untrained people, increased to ≥80% in trained people

• Higher relative exercise intensity can be sustained without the accumulation of blood lactate =
delayed onset of fatigue

  • Strong predictor of endurance performance
  • Applicable to design/optimisation of training

• Optimal intensity for improvements
in endurance fitness

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10
Q

what are Oxygen Uptake Kinetics?

A

The rate at which oxygen uptake changes in response to a change in metabolic demand

• Requires coordination between the respiratory, cardiovascular and muscular systems

• Pulmonary VO2
reflects muscular VO2 to within ±10%

• The faster these kinetics, the less reliance on finite non-oxidative resources

  • The faster these kinetics, the lower the oxygen deficit
  • Response is dependent on exercise intensity
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11
Q

Effect of Training on VO2 Kinetics?

A
  • Highly sensitive to endurance training and HIIT
  • Speeds the phase II time constant
  • Decreases the slow component amplitude
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12
Q

Potential Mechanisms for improved VO2 kinetics: Metabolism?

A

Central: Metabolism

More rapid increase in O2 extraction (Oxidative capacity, Muscle fibre type, Peripheral: muscular)

Speeded Phase 2

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13
Q

Potential Mechanisms for improved VO2 kinetics: Nervous system?

A

central: Nervous system, faster response to altered state:

Enhanced bulk O2 delivery (Central : cardiovascular)

Speeded Phase 2

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14
Q

what is Exercise Economy?

A

• Oxygen cost of a given exercise intensity or speed

• High VO2max is important, but cannot discriminate
performance capability in athletes with similarly high values

  • Exercise economy may explain the difference
  • Good economy can compensate for relatively low VO2 max values in elite athletes
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15
Q

Aerobic performance is comprised of 3 things?

A

Aerobic contribution,

rate of aerobic energy expenditure,

Exercise economy

all of the 3 are interrelated

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16
Q

Aerobic performance: Rate of Aerobic energy expenditure is comprised of 3 parts, what are they?

A

VO2 Kinetics (also related to aerobic contributions),

VO2 max (VO2 max and VO2 Kinetics are interrelated),

Fractional utilisation (%VO2 max)