SEHS 9 - Fatigue

Definition fatigue in sport

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

Active recovery

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

Peripheral fatigue

Develops rapidly and is caused by reduced muscle cell force
(intensity of exercise)
E.g - 100/200/400 m sprint (quick powerful exercises)

Central fatigue

Develops during prolonged exercise and it is caused by impaired function of the central nervous system
(mental fatigue)
E.g - Football/ rugby game/marathon (anything long distance)

Characteristics high intensity activities

- a vigorous bout of exercise
- Less than a second to 2 min
- Anaerobic (without oxygen)
- not enough time to respire aerobically
- Very high heart rate (max: 220-age) 85% of that
- Creatine Phosphate and lactic acid energy dominate
(CP use 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 energy source
- 60-85% of heart rate maximum
- heart rate plateaus when oxygen demands are met (steady rate)

Why do athletes fatigue

- depletion of energy sources (Creatine, phosphate and ATP)
- Reduced motivation or enjoyment
- Increase in levels of products of exercise such as lactate (lactic acid) and hydrogen ions
- Overheating
- Electrolyte imbalance (too much/too little water in body)

EPOC

excess post-exercise oxygen consumption
- Volume of oxygen consumed during recovery sbove resting volume (of breathing)

Reasons for EPOC

- greater intensity of exercise the greater the EPOC
- replenish PC stores
- Resynthesize lactate into muscle glycogen
- replenish myoglobin stores with oxygen
- replacement of liver and muscle glycogen stores
- Impact of CO2/lactic acid levels

Techniques used for recovery

- replacing electrolytes
- Active recovery (stretching muscles)
- Ice bath
- Sleep
- Replacing energy stores (carbohydrates, Proteins)