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Fatigue and Recovery Wk 5

Fatigue: A reversible, exercise-induced decline in performance

  • Two types of fatigue:

    • Peripheral fatigue --> develops rapidly and is caused by reduced muscle cell force

High intensity/short duration:

  • Caused by depletion of energy sources (CP and ATP)

  • Increase in products of exercise (lactate/H+)

  • Depletion of glycogen stores

 

Endurance:

  • Reduction in Ca2+ release

  • Depletion of Ach

  • Dehydration

 

  • Central (or mental) fatigue --> develops during prolonged exercise and is caused by impaired function of the central nervous system

    • When central fatigue occurs, the messages sent via motor neurons to effectors (the muscles) are reduced, e.g. the central nervous system tells the muscle to fire less

    • Can be considered a safety precaution to ensure the demands of organs are balanced --> brain is responsible for activating muscles, but working muscles are a MAJOR competitor for the constant supply of oxygen and glucose that the brain needs to function

Recovery:

6 methods that can assist an athlete in recovery with high training load to recover between session:

  • Replace fluids lost with either water or a solution containing glucose and electrolytes:

    • Glucose and electrolytes optimises fluid absorption and regulating various bodily functions

      • Glucose helps body absorb water and sodium more efficiently

      • Electrolytes (sodium, potassium, chloride e.g.) regulate fluid balance, muscle contractions and nerve signals

 

  • Eat recovery foods rich in CHO (carbohydrates) and protein:

    • Helps with muscle recovery and replenishing energy stores

      • Carbohydrates help replenish glycogen (essential aspect for energy recovery)

      • Protein provides amino acids needed to repair and rebuild muscle tissue damaged during physical activity

 

  • Stretching (combination of both static and dynamic stretching):

    • Improves circulation

    • Enhances mobility

    • Reduces muscle stiffness --> Reduces injury

 

  • Active recovery exercises to keep the blood moving and eliminating H+ ions/speed up EPOC:

    • Increased blood flow eliminates H+ ions by transporting them away from muscle cells to be buffered by the blood (eventually excreted by the kidneys)

      • Maintains pH balance, prevents metabolic acidosis, and reduces muscle fatigue

 

  • Rest allows the muscle tissue to repair and liver and muscle glycogen stores to recover:

    • During exercise, microscopic tears can occur in muscle tissues, BUT rest will be able to allow the body to repair these, leading to stronger muscles

    • Replenishes glycogen stores, reducing muscle fatigue and preparing muscles for the next exercise

 

  • Ice baths have been shown to improve recovery/reduce core temp:

    • Reduces muscle inflammation and soreness after intense workouts

      • Cold water causes vasoconstriction (constricts blood vessels --> reduces blood flow to muscles) --> minimises swelling and tissue breakdown

    • Once exited ice bath, body warms up immediately, causing vasodilation (blood vessels widening) --> flushes out metabolic waste products like lactic acid and brings in fresh blood with nutrients to aid in muscle repair