Cardiorespiratory Adaptations to Training

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Cardiorespiratory Adaptations to Training

• Chapter 13

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Cardiorespiratory endurance

• refers to your bodys ability to sustain
  prolonged, rhythmical exercise.

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Cardiorespiratory Endurance

• Highly related to aerobic development.

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Cardiorespiratory Endurance

• VO2MAX is the best indicator of cardiorespiratory
  endurance.

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VO2MAX

• Absolute and relative measures.
• absolute l . min-1
• relative ml . kg-1 . min-1
• VO2 SV x HR x a-vO2diff

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Cardiovascular Response

• Left ventricle undergoes the most change in
  response to endurance training.
• internal dimensions of the left ventricle
  increase.
• (mostly in response to an increase in
  ventricular filling)

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Cardiovascular Response

• left ventricle wall thickness also increases,
  increasing the strength potential of that
  chambers contractions.

Left Ventricle
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Cardiovascular Response

• Following endurance training, stroke volume
  increases during rest, submaximal levels of
  exercise, and maximal exertion.

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Cardiovascular Response

• A major factor leading to the stroke volume
  increase is an increased end-diastolic volume,
  probably caused by an increase in blood plasma.

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Cardiovascular Response

• Another major factor is increased left
  ventricular contractility.
• This is caused by hypertrophy of the cardiac
  muscle and increased elastic recoil, which
  results from increased stretching of the chamber
  with more diastolic filling.

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Heart Rate Adaptations

• A persons submaximal HR decreases proportionally
  with the amount of training completed.

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Heart Rate Adaptations

• Maximal HR either remains unchanged or decreases
  slightly with training.

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Heart Rate Adaptations

• When a decrease occurs, it is probably to allow
  for optimum stroke volume to maximize cardiac
  output.

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Heart Rate Adaptations

• The HR recovery period decreases with increased
  endurance, making this value well suited to
  tracking an individuals progress with training.

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Heart Rate Adaptations

• However, this is not useful for comparing fitness
  levels of different people.

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Heart Rate Adaptations

• Resistance training can also lead to reduced
  heart rates however, these decreases are not as
  reliable or as large as those seen with endurance
  training.

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Cardiac Output Adaptations

• Cardiac output at rest or during submaximal
  levels of exercise remains unchanged or decreases
  slightly after training.

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Cardiac Output Adaptations

• Cardiac output at maximal levels of exercise
  increases considerably.
• This is largely the result of the submaximal
  increase in maximal stroke volume.

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Blood Distribution Adaptations

• Blood flow to muscles is increased by endurance
  training.

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Blood Distribution Adaptations

• Increased blood flow results from four factors
• Increased capillarization.
• Greater opening of existing capillaries.
• More effective blood redistribution.
• Increased blood volume.

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Blood Pressure Adaptations

• Resting blood pressure is generally reduced by
  endurance training in those with borderline or
  moderate hypertension.

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Blood Pressure Adaptations

• Endurance training has little or no effect on
  blood pressure during standardized submaximal or
  maximal exercise.

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Blood Volume Adaptations

• Blood volume increases as a result of endurance
  training.
• The increase is primarily caused by an increase
  in blood plasma.

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Blood Volume Adaptations

• RBC count can increase, but the gain in plasma is
  typically much higher, resulting in a relatively
  greater fluid portion of the blood.

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Blood Volume Adaptations

• Increased plasma volume causes decreased blood
  viscosity, which can improve circulation and
  oxygen availability.

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Blood Volume Adaptations

• The training-induced increase in plasma volume,
  and its impact on stroke volume and VO2MAX, make
  it one of the most significant training effects.

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Pulmonary Adaptations

• Most static lung volumes remain essentially
  unchanged after training.

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Pulmonary Adaptations

• Tidal volume, though unchanged at rest and during
  submaximal exercise, increases with maximal
  exertion.

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Pulmonary Adaptations

• Respiratory rate remains steady at rest, can
  decrease slightly with submaximal exercise, but
  increases considerably with maximal exercise
  after training.

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Pulmonary Adaptations

• The combined effect of increased tidal volume and
  respiration rate is an increase in pulmonary
  ventilation at maximal effort following training.

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Pulmonary Adaptations

• Pulmonary diffusion at maximal work rates
  increases, probably because of increased
  ventilation and increased lung perfusion.

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Pulmonary Adaptations

• a-vO2diff increases with training, reflecting an
  increased oxygen extraction by the tissues and
  more effective blood distribution.

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Acid-Base Balance Adaptations

• Lactate threshold increases with endurance
  training, which allows you to perform at higher
  rates of work and levels of oxygen consumption
  without increasing your blood lactate above
  resting levels.

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Acid-Base Balance Adaptations

• Maximal blood lactate levels can be increased
  slightly.

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Oxygen Consumption Adaptations

• The respiratory exchange ratio decreases at
  submaximal work rates, indicating a greater
  utilization of free fatty acids.
• It increases at maximal effort.

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Oxygen Consumption Adaptations

• Oxygen consumption can be increased slightly at
  rest.
• It can be decreased slightly or remain unaltered
  during submaximal exercise.

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Oxygen Consumption Adaptations

• VO2MAX increases substantially following
  training, but the amount of increase possible is
  limited in each individual.

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Oxygen Consumption Adaptations

• The major limiting factor appears to be oxygen
  delivery to the active muscles.

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Oxygen Consumption Adaptations

• Although VO2MAX has an upper limit, endurance
  performance can continue to improve for years
  with continued training.

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Oxygen Consumption Adaptations

• An individuals genetic makeup predetermines a
  range for his/her VO2MAX, accounting for 25 to
  50 of the variance in VO2MAX values.

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Oxygen Consumption Adaptations

• Heredity also largely explains individual
  variations in response to identical training
  programs.

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Oxygen Consumption Adaptations

• Age-related decreases in aerobic capacity might
  partly result from decreased activity.

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Oxygen Consumption Adaptations

• Highly conditioned female endurance athletes have
  VO2MAX values only about 10 lower than those of
  highly conditioned male endurance athletes.
• Body size
• Hemoglobin content
• Percent lean mass

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Oxygen Consumption Adaptations

• To maximize cardiorespiratory gains, training
  should be specific to the type of activity the
  exerciser usually performs.

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Oxygen Consumption Adaptations

• Resistance training in combination with endurance
  training does not appear to restrict improvement
  in aerobic capacity and may increase short-term
  endurance.

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Oxygen Consumption Adaptations

• All exercisers can benefit from maximizing their
  endurance.

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Determining Exercise Intensity

• For basic health and fitness
• 40-45 of heart rate or VO2 reserve, or 50-64 of
  heart rate max

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Determining Exercise Intensity

• For optimal health and fitness
• 50-85 of heart rate or VO2 reserve, or 65-90 of
  heart rate max

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Determining Exercise Intensity

• Heart rate max
• Calculated by 208 0.7(age)

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Determining Exercise Intensity

• Heart Rate Reserve
• Heart rate max resting heart rate
• VO2 Reserve
• VO2max resting VO2

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Determining Exercise Intensity

• Sample calculation based on HRres
• Find HRmax
• 208-0.7(age) 208-0.7(20) 194
• HRmax HRrest 194-70 127
• HRR times 127 x .50 63.5
• 50-85 127 x .85 108
• Add HRrest 64 70 134
• 108 70 178

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Determining Exercise Intensity

• Sample calculation based on VO2res
• Measure or estimate VO2 max
• Find VO2 res
• VO2max VO2 rest 45 3.5 41.5
• VO2res times 41.5 x .50 20.75
• 50 and 85 41.5 x .85 35.28
• Add VO2 rest 20.75 3.5 24.25
• 41.5
  3.5 45

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Determining Exercise Intensity

• Based on HR max
• 208 0.7(age) 208-0.7(20) 194
• Times 65-90 194 x .65 126
• 194 x
  .90 175