Fatigue can be described as a ‘generic term used to explain feelings of muscular tiredness or laboured breathing during exercise’ (Wesson et al, 2001). During exercise a performer will reach a point where they can no longer continue exercising at the same intensity this can also be defined as fatigue. Fatigue will always result in the decrease of performance. Fatigue can effect the body in either two ways; chemically, this is where the nervous actions of the body become disrupted this is called neural fatigue.
Another way in which the body can be affected is mechanically, this is the disturbance of physiological functioning this is called muscular fatigue. Neural and muscular fatigue combine together to produce neuromuscular fatigue. Fatigue can be caused by various different factors. An insufficient source of ATP can cause fatigue. As ATP is required for all muscle actions when ATP is no longer available performance then stops, therefore a lack of ATP is responsible for muscular fatigue.
A sporting example of when this occurs is at the end of a 200m sprint. Depletion of fuels. In order for ATP generation to occur and therefore to make muscular movement fuels are required for the generation to take place. Glucose, glycogen and fat are fuels which are needed, glycogen is a key fuel which is stored in muscles and if this fuel level is low, performance levels will soon decrease as a result. Performance levels will decrease because of muscular fatigue.
A sporting example of when this occurs is near the end of a marathon run. Decreased availability of calcium As the body exercises a build up of lactic acid causes calcium stop being released. This results in muscular contraction not being able to take place as calcium ions enables the sliding filament theory to occur which causes muscular contraction. A sporting example of when this occurs is near to the end of a football match. Failure of neural transmission
This creates fatigue as no impulse can be transported so therefore no muscular contraction can take place. For a muscular contraction to take place the nerve impulse must pass through the synaptic cleft in order to reach the muscular fibre. The transport of the impulse cannot occur in fatigued muscles because acetylcholine cannot be replenishment and put back into the synapse. A sporting example of when this occurs is near to the end of a 5000m run.