Fatigue Flashcards
Define fatigue
An exercised induced reduction in the power generating capacity of a muscle, and an inability to continue the exercise
What are the three types of fatigue
Local
General
Chronic
What is local fatigue
Fatigue that occurs in a muscle or specific group of muscles. Occurs when a particular muscle is repeatedly called upon in training such as the biceps
What is general fatigue
This involves all of the muscles in the body feeling tired and worn out after a training session. Individuals feel soreness in all of their body muscles, potentially triggering psychological fatigue. An example is the fatigue experienced after a basketball game
What is chronic fatigue
A breakdown in an individuals immune system due to overtraining or inappropriate/unsuitable recovery strategies. It can lead to the development of glandular fever, making athletes susceptible to illness.
What is multifactorial and how does it relate to fatigue
Multifactorial refers to something that is dependent on a variety of factors. In relation to fatigue, it is classified as multifactorial, being influenced by different factors
What causes fatigue
- Fuel depletion
- Metabolic byproducts
- Neuromuscular events
- Elevated body temperature
Explain fuel depletion in the contribution of fatigue
It depends on the specific energy system concerned:
- Depletion of ATP and PC in ATP-PC system trigger fatigue
- Depletion of glycogen stores within the muscles trigger fatigue in the aerobic system. This results in using glycogen in the liver, then fats, then proteins (extreme cases)
What are the two metabolic byproducts that trigger fatigue? Explain how they do so?
- Hydrogen ions
- ADP + Pi
Hydrogen ions combine with oxygen in aerobic respiration to produce water. But in anaerobic respiration they accumulate within the muscles, causing the muscular environment to become acidic. This can potentially lead to the development of acidosis. Hydrogen ions inhibit muscular contractions as it reduces enzyme function and the breakdown of glucose.
The presence of inorganic phosphate decreases the contractile force of muscles, reducing the strength of muscular contractions. It can also reduce the neural signal transmission.
What was the previous misconception towards lactate?
Lactate was perceived to be a negative factor, responsible for Delayed Onset Muscle Soreness. But lactate is also able to transport some of the H+ ions that accumulate as a byproduct of anaerobic glycolysis, reducing muscle acidity and the possibility for acidosis.
How does Neuromuscular Events trigger fatigue??
The CNS can detect fatiguing of the body, causing:
-decrease in the frequency and intensity of the electrical impulses
= intensity and work rate of the working muscles is reduced
-decrease in the release of acetylcholine within the body. Results in a decrease in the force of the muscular contractions, also decreasing muscular contraction stimulation.
How does increased body temperatures contribute towards fatigue?
-continual sweating
This can impair the bodies thermoregulation, muscle endurance and neuromuscular coordination. This can decrease muscle function and potentially result in unconsciousness.
How does the LIP contribute to fatigue
When the lactate inflection point is reached, the rate of lactate production exceeds lactate removal, resulting in an accumulation of lactate that causes fatigue within the muscles.
