TOPIC 9 - Fatigue Flashcards
9.1.1 Define fatigue in sports
A reversible, exercise-induced decline in performance
9.1.2. Outline the different types of fatigue
Peripheral Fatigue
- Develops rapidly and is caused by reduced muscle cell force
Mechanisms operating within the muscle that affect the ability of the muscle itself to produce force
Central Fatigue
- Develops during prolonged exercise and is caused by impaired function of the central nervous system
Mechanisms operating outside the muscle that inhibit muscle activation and reduce force production
9.1.3. Distinguish between high intensity and endurance activities
High intensity exercise
- Vigorous bouts of intense activity
- Less than 1 sec or up to 1-2min
- Anaerobic
Endurance activities
- Prolonged sessions of low-intensity activity
- Several minutes to several hours
- Aerobic
9.1.4. Discuss causes of fatigue in different types of activity or exercise
High intensity Vs endurance
Development of peripheral fatigue in high-intensity activities:
- depletion of energy sources (ATP & CP)
- Increased levels of biproducts (H+ & lactate)
Development of peripheral fatigue in endurance activities:
- depletion of muscle and liver glycogen reserves
- reduction in Ca2+ release
- depletion of acetylcholine
- dehydration, electrolyte loss, overheating
9.1.5. Discuss recovery from fatigue after sports
- Different aspects of recovery can occur at different rates
- Recovery rate depend on the type of activity (high-intensity, team sports or endurance)
Excess post-exercise oxygen consumption (EPOC)
Fast replenishment:
- Restoration of muscle phosphagens (ATP & CP)
- Takes up to 3 min for full restoration
- Uses 2–3 litres of oxygen
Slow replenishment
- Removal of lactic acid
- Takes up to an hour
- Uses 5–6 litres of oxygen
Describe the possible causes of fatigue during exercise bouts lasting 15-30s and 2-4 hours.
- Exercise bouts at 15-30 seconds will usually lead to peripheral fatigue if it is anaerobic and at high intensity –> Depletion of energy stores of ATP and CP
- Central fatigue may be the result of exercising in aerobic, prolonged bouts of 2-4 hours due to impaired function of the CNS
- Peripheral fatigue may occur during bouts of exercise 2-4 hours long due to depletion of muscle and liver glycogen stores, reduction in Ca2+ release, depletion of acetylcholine, dehydration, overheating and electrolyte loss