Fatigue

Fuel depletion (Glycogen Depletion)

Lasts for moderete to high intensities for 1.5-2hours. When glycogen depletion occurs atheletes will start using fats as the primary energy source. Due to the significantly slow rate the athelete will experience fatigue and begin to slow down.

Fuel depletion (ATP Depletion)

When rapid energy is required to perform explosively, the rate of ATP breakdown also increases rapidly. ATP levels drop or deplete momentarily whilst more ATP is rebuilt leading to a small drop in power output, until the two anaerobic systems combine to resynthesise ATP the fastest.

Fuels post-exercise

High GI carbs in the first 30mins post exercise to help replenish glycogen stores quicker.

Co-ingest carbs and protein because it prolonges the window of insulin sensitivity in muscles allowing more glycogen to be stored

Electrolytes and fluds for hydration

Accumulation of metabolic by-products (inorganic phosphate)

When ATP-PC is the major contributer Pi is produced when CP splits and when it accumulates it slows down the release and uptake of calcium ions which enable muscle contraction. The build up of Pi slows down muscle contraction and causes a reduction in force production and power output

Thermoregulatory Fatigue

Elevated body tempreture results in increased sweat which results in increased blood flow to the skin (vasodilation), decreased blood flow to muscles (vasoconstriction), decreased oxygen delivery to muscles, decreased aerobic enregy production which results in the accumulation of metabolic by products meaning fatigue.

Elevated body tempreture also results in loss of blood plasma resulting in loss of total blood volume, increase in blood viscosity and increase in heart rate. This all reults in the body having to work harder to maintain intensity resulting in fatigue

Carbohydrate Loading

It increased muscle glycogen stores which can delay glycogen depletion and can be of benifit for events lasting 90mins or longer