Fatigue
Fatigue is an exercise induced reduction in maximal force / power-generating capacity of a muscle & an inability to continue activity.
The onset & rate of development of fatigue is dependent on the:
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Fuel Depletion
Means the depletion of energy fuels or substrates that serve to power muscular contractions, which include:
To specifically identify which fuels are being depleted & are likely to cause a decrease in performance its essential to consider the duration & intensity of the activity. During very high intensity, short-duration anaerobic-type activities, the depletion of ATP & then PC are the most common cause of fatigue for Usain Bolt. |
Metabolic By-Products
The accumulation of metabolic by-products, or metabolites are substances produced as a result of chemical reactions within the body associated with the production of energy for ATP resynthesis. They are the ‘leftovers’, & include:
Inorganic Phosphate
Pi accumulation is probably the largest contributor to fatigue in exercise of any duration. Pi accumulation interferes with the role that Ca+2, plays in the contractile process. Pi reduces the amount of calcium that can released by the sodium-potassium pump. Pi inhibit the myosin crossbridges pulling actin filaments, which reduce force production. Recovery StrategiesRecovery aims to return the body to pre-exercise conditions and in doing so, reverse the effects of fatigue. Must match the recovery strategy to the most likely cause(s) of fatigue.
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For Usain Bolt, the 100m sprint would involve refuelling ATP and PC muscle stores (passive recovery and for the 200m sprint, it would be about the removal of metabolic byproducts (H+ in plasma and muscle, & Pi & ADP).
An active recovery is recommended to speed up the removal of H+ ions from muscles, as it extends EPOC which will assist the athlete to recover more quickly by:
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Cryotherpy
Assists with the dissipation of blood & waste products away from any damaged areas. It is also thought to decrease DOMS. Massage
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