First Year Physiology

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First Year Physiology

• Aerobic Fitness II Different Types of Training

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Aims

• To appreciate different types of exercise,
  delimited by intensity.
• To understand the differences in stress and
  adaptation to different intensities of aerobic
  training.
• To appreciate practical rules that help in
  exercising at the correct intensity.
• What constitutes optimal preparation for
  endurance exercise.

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Overview

• Ways of measuring exercise intensity.
• Different exercise intensities.
• Lactate Threshold as a concept.
• Preparation for training and appropriate recovery.

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Assessing Exercise Intensity

• Borg Scale (RPE)
• Velocity/Power Output (Performance)
• Oxygen Consumption
• Heart Rate
• Blood Lactate concentration (caution)

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Categorising Exercise Intensity

• Moderate - no elevation of blood lactate
  (production rte equals removal rate). Complete
  Long Slow Distance (LSD) runs at this intensity.
• Heavy - begins at lactate threshold and ends at
  the maximum lactate steady state (MLSS). Zone in
  which threshold training occurs.
• Severe - above MLSS up to maximal oxygen uptake.
  Perform aerobic interval training in this domain.

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Moderate Exercise

• Below Lactate Threshold (LT).

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Long Slow Distance Training

• Running at 50-60 , for 15-250 km
  (for highly trained athletes).
• Designed to increase the the ability of the
  active musculature to utilise fat (reservation of
  glycogen stores).
• Trains volume and distance tolerance. Ability to
  cope with structural damage and metabolic
  disturbance of long distance or high volume.

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Heavy Intensity

• In between Lactate Threshold (LT) and Maximum
  Lactate Steady State (MLSS).

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Lactate Threshold (LT)

• LT the point at which blood lactate
  concentration suddenly and continually begins to
  increase (often expressed as a velocity or power
  output).
• Seen as important for endurance performance,
  because it represents the maximum intensity at
  which exercise occurs, without a rise in lactate
  and associated fatigue (hydrogen ions).
• See last weeks lecture for reasons for
  increase in lactate production.
• Tends to occur at between 55-80 ,
  depending on mode of exercise and training
  status.

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Lactate Threshold
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Maximum Lactate Steady State

• The highest running speed (intensity) at which
  blood lactate concentration, although elevated,
  can be stabilised.

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Training Study

• Henritze et.al. (1985, in Weltman 1995) examined
  the effects of training at LT, and above LT, on
  changes in LT and .
• College aged women who trained at the LT did not
  improve LT or . Those that trained
  above the LT improved LT by 47 (when expressed
  as at LT).

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Adaptations to Threshold Training

• It is believed that changes to threshold are a
  result of a different mechanism than changes to
  .
• Changes in threshold are likely to come
  predominantly from local/peripheral changes, in
  the trained muscle (e.g. increased mitochondrial
  content, preferred utilisation of fats and other
  enzymatic changes, increased capillary density).
• Little is known about the optimum intensity to
  improve LT, but continuous training for 20-40
  mins at a level just above LT has been
  traditionally used.

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Severe Intensity Exercise

• Above lactate minimum steady state (MLSS).
• High intensity at which fatigue quickly sets in.

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Aerobic Intervals

• Because this level of exercise results in fairly
  rapid fatigue, it can only be performed for a
  limited period.
• To ensure an adequate volume of exercise takes
  place at this level, we perform intervals with an
  active recovery in between bouts.
• We run at or close to for 4
  minutes, then 4 minutes of active recovery (a
  very low level) allow us to perform the next bout
  at the same intensity.
• Traditionally athletes will complete 3-6 bouts of
  severe intensity exercise in a session.

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Aerobic Intervals

• Provides variation in training.
• Allows volume of severe intensity exercise to be
  increased due to recovery.
• Thought to stimulate predominantly central
  adaptations. No clear evidence to support this.

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Further Reading

• Wilmore and Costill (1994) Chapter 7