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neurologyYou need to know

• Excess post-exercise oxygen consumption (EPOC) is the volume of oxygen consumed above resting level as the body returns towards its pre-exercise state.
• An oxygen deficit occurs at the start of exercise because oxygen demand rises faster than the cardiovascular and respiratory systems can increase oxygen delivery.
• The fast component of EPOC, also called alactacid recovery, restores ATP and phosphocreatine stores and reoxygenates haemoglobin and myoglobin.
• The fast component of EPOC lasts for a few minutes and does not involve the removal of lactate.
• The slow component of EPOC, also called lactacid recovery, supports lactate processing and remains elevated while heart rate, breathing rate, hormones and body temperature return towards resting levels.
• Lactate can be oxidised as an energy source or transported to the liver and converted into glucose.
• Higher-intensity or longer-duration exercise generally creates a larger oxygen deficit and EPOC, so more recovery time is required before another demanding exercise session.
• At altitude, barometric pressure and the partial pressure of oxygen are lower, reducing the diffusion of oxygen from the alveoli into the blood.
• Acute exposure to altitude increases breathing rate, tidal volume and heart rate to compensate for the reduced availability of oxygen.
• Stroke volume can decrease at altitude, meaning heart rate must rise to help maintain cardiac output during exercise.
• Altitude reduces maximal oxygen uptake and aerobic endurance performance, with the negative effect becoming greater as altitude and exercise intensity increase.
• Acclimatisation is the process of making physiological adaptations after spending time at altitude.
• During acclimatisation, ventilation increases and the kidneys release more erythropoietin, stimulating the production of red blood cells and increasing the blood's oxygen-carrying capacity.
• Plasma volume initially decreases at altitude, while longer-term increases in red blood cells and haemoglobin improve oxygen transport.
• Arrival at altitude must be timed carefully because athletes may either arrive shortly before competition to limit acute disruption or arrive sufficiently early, usually around two weeks or more, to acclimatise.
• Thermoregulation is the control of core body temperature, mainly through sweating, evaporation and changes in blood flow to the skin during exercise.
• Humidity is the amount of water vapour in the air; high humidity reduces sweat evaporation and therefore reduces the body's ability to lose heat.
• Exercise in the heat causes vasodilation and redirects more blood towards the skin, creating competition between supplying the working muscles and supporting heat loss.
• Cardiovascular drift is the gradual rise in heart rate and fall in stroke volume during prolonged exercise, particularly in the heat, because of dehydration, reduced plasma volume and increased skin blood flow.
• Hyperthermia is an abnormally high core body temperature; it increases physiological strain, raises ventilation and heart rate, accelerates dehydration and can impair performance or cause heat illness.

• Explain the fast and slow components of EPOC by linking each component to the physiological processes that restore the body towards its pre-exercise state.
• Compare recovery after low- and high-intensity exercise, using oxygen deficit and EPOC to justify differences in recovery time.
• Plan the order, intensity and recovery intervals of an exercise session so that demanding activities are not limited by incomplete recovery.
• Analyse altitude-performance information by linking increasing altitude to oxygen availability, maximal oxygen uptake and aerobic exercise performance.
• Explain acute responses and longer-term acclimatisation to altitude by tracing changes through the respiratory and cardiovascular systems.
• Recommend an appropriate arrival strategy for exercise at altitude, considering the time required for acclimatisation and the risk of acute altitude effects.
• Analyse exercise in different temperatures and humidity levels by linking sweat evaporation, skin blood flow, cardiovascular drift and core temperature to performance.
• Compare the effects of heat on the cardiovascular and respiratory systems, including changes in heart rate, stroke volume, blood distribution and ventilation.
• Evaluate whether exercise intensity or duration should be reduced in hot or high-altitude conditions, using physiological evidence to justify the decision.