Fatigue - Kai flashcards

Key terminology:

Fatigue in sport - a reversible feeling of exhaustion and decrease in your ability to produce force leading to a decline in performance

Peripheral Fatigue - Develops rapidly and is caused by reduced muscle cell force
Examples: 100m sprint, 200m, 400m (quick powerful exercises)
- Peripheral fatigue refers to the motor units and involves processes associated with mechanical and cellular changes in the muscular system.

Central Fatigue - (mental fatigue) Develops during prolonged exercise and is caused by impaired mental function of the central nervous system.
Examples: Maraton, football game, rugby game (Anything long distance)
- Central fatigue refers to the physiological processes that occur within the central nervous system.

9.1.3

Distinguish between high-intensity and endurance activities

Characteristics of high-intensity activities:

  • yVigorous bout of exercise

  • Less than a second to 2 minutes

  • Anaerobic (without oxygen)

  • Not enough time to respire aerobically

  • Very high heart rate (max 220 - age) 85% of that

  • Creatine phosphate and lactic energy dominate (use creative phosphate first but only up to 8 seconds)

Characteristics of Endurance Activities

  • Prolonged session over 2 min to hours

  • low to medium intensity

  • Aerobic (with oxygen) respiration as an energy source

  • 60-85% of heart rate maximum

  • Heart rate plateaus when oxygen demands are met (steady state)

9.1.4

Why do athletes fatigue?

  • depletion of energy sources (creatine phosphate and ATP)

  • Increase in levels of the products of exercise such as lactic acid and hydrogen ions

  • Reduced motivation or enjoyment

  • Overheating

  • Electrolyte imbalance (too much or too little water in the body)

High-intensity activities such as weight lifting. - Causes of peripheral fatigue:
Lack of energy delivery and excess of physical activity and accumulation of by-products cause failure for the muscle to contract.

Rate of depletion of energy sources creatine phosphate and ATP
———— CP is used in anaerobic conditions
———— Maintains ATP levels in muscle
———— Depletion of CP causes fatigue

Increase in levels of by-products
———— Lactic acid is a by-product of anaerobic respiration glycolysis

Activities of a short duration + high intensity rely on glycolysis

Medium endurance activities such as a marathon - Causes of peripheral fatigue
Depletion of muscle and liver glycogen reserves

reduction in calcium release - reduces muscle ability to perform contractions effectively

Dehydration - decreases the effectiveness of waste products

overheating - impairs muscular function

depletion of acetylcholine - decreases the effectiveness of action potential to pass to muscle fibres

electrolyte loss - decreased nerve function

9.1.5 - Recovery from fatigue after sport

Active recovery - Low-intensity exercise to promote recovery either immediately after or in the days following an intense training session or competition.

Excess post-exercise consumption (EPOC) - The volume of oxygen consumed during recovery above resting volume (of breathing)

HPE - Term 1 Body Systems Definitions Diagram | Quizlet

Reasons for EPOC:
The greater intensity the greater the EPOC

  • restoration of muscle creatine phosphate stores

  • removal of lactic acid

  • replenishment of myoglobin stores

  • replacement of muscle and liver glycogen stores.

Different techniques used for recovery:
- Replacing electrolytes
- Active recovery {Stretching muscles}
- Ice bath
- Sleep
- Replacing energy stores (Carbohydrates and proteins)