Topic 9 - Fatigue

• Fatigue is a reversible exercise-induced decline in athletic performance
• Peripheral Fatigue:

  • Occurs in the muscle and develops rapidly
  • Caused by reduced muscle force
  • Commonly linked to high-intensity activities
  • Peripheral fatigue can be localised
  • Recovery is quicker than central fatigue
  • Can be due to: muscles contracting repeatedly without resting, depletion of CP stores, accumulation of fatiguing by products
• Central Fatigue:

  • develops during prolonged exercise
  • caused by impaired function of the central nervous system
  • Commonly linked to endurance activities
  • Affects the whole body
  • Can be due to overheating, dehydration, lack of glucose stores
• High-intensity exercise:

  • involves vigorous bouts of intense activity
  • Lasts for less than 2 mins
  • Major sources of energy are from anaerobic processes using ATP and CP
  • e.g. weight lifting, plyometrics, interval training
• Endurance Activity

  • Lasts for several hours or mins
  • Prolonged sessions of low intensity activity
  • Major sources of energy are aerobic processes using Carbohydrates, fats and proteins
  • e.g. cycling, jogging, swimming
• Causes of peripheral fatigue in endurance activities:

  • Aerobic performance is hindered by a depletion in glycogen stores as ATP synthesis slows
  • a reduction in Calcium release reduces the ability of muscles to contract effectively
  • depletion of acetylcholine reduces the ability of an action potential to pass to the muscle fibres
  • electrolyte loss through sweating which can lead to cramps
  • dehydration can occur due to the loss of essential fluids
  • overheating can impair muscle function
• Causes of Peripheral fatigue in HIT activities:

  • Depletion of ATP and CP stores
  • increase in levels of the products of exercise such as lactic acids and hydrogen ions
• Fatigue is perceived differently by athletes and depends on age, level of fitness and the type of exercise
• Peripheral fatigue: fatigue caused by the body's muscle groups
• Central Fatigue: The accumulation of fatigue in the central nervous system.
• Central fatigue is caused by failure of neural transmission