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HMS, BM EQ-Bank 880

Analyse how altitude training and vascular disease affect cardiovascular efficiency, and explain strategies an endurance athlete might implement to optimise cardiovascular function despite these influences.   (12 marks)

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Sample Answer

Overview Statement

  • Altitude training and vascular disease both affect cardiovascular efficiency but through opposing mechanisms.
  • Key components include oxygen delivery, blood vessel function, and adaptation capacity.
  • Athletes must understand these relationships to optimise their cardiovascular function.

Altitude Training Impact

  • Initial altitude exposure reduces cardiovascular efficiency through hypoxic stress.
  • Low oxygen availability triggers the body to produce more red blood cells and haemoglobin.
  • These adaptations enhance oxygen-carrying capacity over several weeks.
  • Once developed, improvements benefit performance when returning to sea level.
  • However, these effects are temporary and reversible.

Vascular Disease Impact

  • Atherosclerotic plaque buildup permanently narrows arteries, reducing blood flow.
  • Narrowed vessels force the heart to work harder, decreasing efficiency.
  • Unlike altitude adaptations, vascular disease creates irreversible tissue damage.
  • Progressive arterial dysfunction leads to uneven blood flow distribution.
  • Such changes prevent optimal oxygen delivery regardless of other adaptations.

Contrasting Relationships

  • Altitude creates systemic hypoxia that stimulates positive adaptations.
  • Vascular disease causes localised hypoxia that prevents normal function.
  • While altitude effects are temporary and beneficial, vascular disease requires ongoing management.
  • The key difference lies in reversibility and adaptive potential.

Optimisation Strategies – Altitude Training

  • Implement gradual altitude exposure to maximise adaptations safely.
  • Use “live high, train low” protocols to maintain training quality.
  • Time altitude camps appropriately before competitions.
  • Consider altitude tents when natural altitude is unavailable.

Optimisation Strategies – Vascular Disease Management

  • Maintain regular moderate-intensity aerobic exercise to promote arterial health.
  • Follow anti-inflammatory nutrition to reduce vascular damage.
  • Implement stress management protocols.
  • Monitor cardiovascular responses objectively during training.
  • Collaborate with medical specialists for appropriate interventions.
Show Worked Solution

Sample Answer

Overview Statement

  • Altitude training and vascular disease both affect cardiovascular efficiency but through opposing mechanisms.
  • Key components include oxygen delivery, blood vessel function, and adaptation capacity.
  • Athletes must understand these relationships to optimise their cardiovascular function.

Altitude Training Impact

  • Initial altitude exposure reduces cardiovascular efficiency through hypoxic stress.
  • Low oxygen availability triggers the body to produce more red blood cells and haemoglobin.
  • These adaptations enhance oxygen-carrying capacity over several weeks.
  • Once developed, improvements benefit performance when returning to sea level.
  • However, these effects are temporary and reversible.

Vascular Disease Impact

  • Atherosclerotic plaque buildup permanently narrows arteries, reducing blood flow.
  • Narrowed vessels force the heart to work harder, decreasing efficiency.
  • Unlike altitude adaptations, vascular disease creates irreversible tissue damage.
  • Progressive arterial dysfunction leads to uneven blood flow distribution.
  • Such changes prevent optimal oxygen delivery regardless of other adaptations.

Contrasting Relationships

  • Altitude creates systemic hypoxia that stimulates positive adaptations.
  • Vascular disease causes localised hypoxia that prevents normal function.
  • While altitude effects are temporary and beneficial, vascular disease requires ongoing management.
  • The key difference lies in reversibility and adaptive potential.

Optimisation Strategies – Altitude Training

  • Implement gradual altitude exposure to maximise adaptations safely.
  • Use “live high, train low” protocols to maintain training quality.
  • Time altitude camps appropriately before competitions.
  • Consider altitude tents when natural altitude is unavailable.

Optimisation Strategies – Vascular Disease Management

  • Maintain regular moderate-intensity aerobic exercise to promote arterial health.
  • Follow anti-inflammatory nutrition to reduce vascular damage.
  • Implement stress management protocols.
  • Monitor cardiovascular responses objectively during training.
  • Collaborate with medical specialists for appropriate interventions.

HMS, BM EQ-Bank 879

Analyse how THREE different factors that impact the cardiovascular system affect an endurance athlete's performance.   (8 marks)

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Sample Answer

Overview Statement

  • Three key factors impact cardiovascular efficiency in endurance athletes: altitude, haemoglobin levels, and vascular disease.
  • Each factor influences oxygen delivery to working muscles differently.
  • Performance outcomes depend on the interaction between these factors.

Altitude and Cardiovascular Adaptation

  • Altitude exposure reduces atmospheric oxygen pressure, triggering physiological adaptations.
  • The body responds by increasing red blood cell and haemoglobin production.
  • Gradual acclimatisation enhances oxygen-carrying capacity over several weeks.
  • Such adaptations benefit endurance athletes when returning to sea level.

Haemoglobin Levels and Oxygen Transport

  • Haemoglobin directly determines the blood’s oxygen-carrying capacity.
  • Higher levels enable greater oxygen delivery to muscles during exercise.
  • Iron deficiency reduces haemoglobin production, limiting endurance capacity.
  • Optimal haemoglobin levels therefore support sustained aerobic performance.

Vascular Disease Impact

  • Atherosclerosis progressively narrows arteries through plaque buildup, restricting blood flow.
  • Reduced arterial diameter limits oxygen delivery regardless of haemoglobin levels.
  • Even mild narrowing affects exercise capacity and cardiovascular efficiency.
  • Vascular health consequently determines the effectiveness of other adaptations.

Implications and Synthesis

  • All three factors interact to determine overall cardiovascular efficiency.
  • Altitude training benefits may be negated by poor vascular health or low haemoglobin.
  • Regular screening helps identify vascular issues early.
  • Maintaining adequate iron intake ensures optimal haemoglobin production.
  • An integrated approach maximises endurance performance potential.
Show Worked Solution

Sample Answer

Overview Statement

  • Three key factors impact cardiovascular efficiency in endurance athletes: altitude, haemoglobin levels, and vascular disease.
  • Each factor influences oxygen delivery to working muscles differently.
  • Performance outcomes depend on the interaction between these factors.

Altitude and Cardiovascular Adaptation

  • Altitude exposure reduces atmospheric oxygen pressure, triggering physiological adaptations.
  • The body responds by increasing red blood cell and haemoglobin production.
  • Gradual acclimatisation enhances oxygen-carrying capacity over several weeks.
  • Such adaptations benefit endurance athletes when returning to sea level.

Haemoglobin Levels and Oxygen Transport

  • Haemoglobin directly determines the blood’s oxygen-carrying capacity.
  • Higher levels enable greater oxygen delivery to muscles during exercise.
  • Iron deficiency reduces haemoglobin production, limiting endurance capacity.
  • Optimal haemoglobin levels therefore support sustained aerobic performance.

Vascular Disease Impact

  • Atherosclerosis progressively narrows arteries through plaque buildup, restricting blood flow.
  • Reduced arterial diameter limits oxygen delivery regardless of haemoglobin levels.
  • Even mild narrowing affects exercise capacity and cardiovascular efficiency.
  • Vascular health consequently determines the effectiveness of other adaptations.

Implications and Synthesis

  • All three factors interact to determine overall cardiovascular efficiency.
  • Altitude training benefits may be negated by poor vascular health or low haemoglobin.
  • Regular screening helps identify vascular issues early.
  • Maintaining adequate iron intake ensures optimal haemoglobin production.
  • An integrated approach maximises endurance performance potential.

HMS, BM EQ-Bank 878

Evaluate the role of haemoglobin in cardiovascular efficiency and how variations in haemoglobin levels might impact an athlete's ability to recover between training sessions.   (8 marks)

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Sample Answer

Evaluation Statement

  • Haemoglobin plays a critical role in cardiovascular efficiency, with optimal levels being essential for athletic recovery.
  • Evaluation based on oxygen transport capacity and recovery speed.

Oxygen Transport Capacity

  • Haemoglobin is the primary oxygen-carrying protein in red blood cells.
  • Higher levels increase oxygen delivery to muscles during and after exercise.
  • Each haemoglobin molecule carries four oxygen molecules, maximising transport.
  • Athletes with optimal haemoglobin levels show superior oxygen delivery.
  • Low levels force the heart to work harder, reducing cardiovascular efficiency.
  • This criterion strongly supports haemoglobin’s vital role in performance.

Recovery Speed Between Sessions

  • Adequate haemoglobin ensures rapid ATP replenishment post-exercise.
  • Oxygen availability determines muscle repair and glycogen restoration rates.
  • Iron-deficiency anaemia significantly extends recovery time between sessions.
  • Female athletes face higher risks due to menstruation and dietary factors.
  • Reduced haemoglobin delays waste product removal, prolonging muscle fatigue.
  • Evidence clearly demonstrates faster recovery with optimal haemoglobin levels.

Final Evaluation

  • Haemoglobin is fundamental to cardiovascular efficiency and athletic recovery.
  • Maintaining optimal levels through nutrition and monitoring is crucial for training adaptations.
  • The evidence overwhelmingly supports haemoglobin’s critical role in determining recovery capacity.
Show Worked Solution

Sample Answer

Evaluation Statement

  • Haemoglobin plays a critical role in cardiovascular efficiency, with optimal levels being essential for athletic recovery.
  • Evaluation based on oxygen transport capacity and recovery speed.

Oxygen Transport Capacity

  • Haemoglobin is the primary oxygen-carrying protein in red blood cells.
  • Higher levels increase oxygen delivery to muscles during and after exercise.
  • Each haemoglobin molecule carries four oxygen molecules, maximising transport.
  • Athletes with optimal haemoglobin levels show superior oxygen delivery.
  • Low levels force the heart to work harder, reducing cardiovascular efficiency.
  • This criterion strongly supports haemoglobin’s vital role in performance.

Recovery Speed Between Sessions

  • Adequate haemoglobin ensures rapid ATP replenishment post-exercise.
  • Oxygen availability determines muscle repair and glycogen restoration rates.
  • Iron-deficiency anaemia significantly extends recovery time between sessions.
  • Female athletes face higher risks due to menstruation and dietary factors.
  • Reduced haemoglobin delays waste product removal, prolonging muscle fatigue.
  • Evidence clearly demonstrates faster recovery with optimal haemoglobin levels.

Final Evaluation

  • Haemoglobin is fundamental to cardiovascular efficiency and athletic recovery.
  • Maintaining optimal levels through nutrition and monitoring is crucial for training adaptations.
  • The evidence overwhelmingly supports haemoglobin’s critical role in determining recovery capacity.

HMS, BM EQ-Bank 877 MC

Which statement correctly describes the relationship between haemoglobin levels and cardiovascular efficiency?

  1. Lower haemoglobin levels increase oxygen delivery to muscles during exercise
  2. Higher haemoglobin levels cause atherosclerosis in the arteries
  3. Higher haemoglobin levels improve oxygen-carrying capacity of blood
  4. Haemoglobin levels only affect cardiovascular efficiency at high altitudes
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\(C\)

Show Worked Solution
  • C is correct. Higher haemoglobin levels improve oxygen-carrying capacity of blood, enhancing cardiovascular efficiency.

Other Options:

  • A is incorrect: Lower haemoglobin reduces oxygen delivery
  • B is incorrect: Haemoglobin doesn’t cause atherosclerosis
  • D is incorrect: Haemoglobin affects cardiovascular efficiency at all altitudes

HMS, BM EQ-Bank 876 MC

An athlete is training at 2500 metres above sea level. What physiological adaptation is MOST likely to occur as a result of acclimatisation to high altitude?

  1. Decreased heart rate during rest and exercise
  2. Increased production of red blood cells and haemoglobin
  3. Widening of blood vessels to allow greater blood flow
  4. Reduced lactic acid production during maximal exercise
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\(B\)

Show Worked Solution
  • B is correct. Altitude acclimatisation results in increased production of red blood cells and haemoglobin to compensate for lower oxygen availability.

Other Options:

  • A is incorrect: Heart rate actually increases at altitude, especially during initial exposure.
  • C is incorrect: Blood vessels don’t widen significantly during altitude acclimatisation.
  • D is incorrect: Lactic acid production may actually increase at altitude during exercise.

HMS, BM EQ-Bank 875 MC

Which of the following best describes the primary cause of vascular disease that impacts the cardiovascular system's efficiency?

  1. Low haemoglobin levels in the blood
  2. Atherosclerosis (build-up of plaque on artery walls)
  3. Decreased oxygen partial pressure at high altitude
  4. Iron deficiency in red blood cells
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\(B\)

Show Worked Solution
  • B is correct. Atherosclerosis is the primary cause of vascular disease that impacts cardiovascular efficiency by narrowing arteries and reducing blood flow.

Other Options:

  • A is incorrect: Low haemoglobin is a separate factor affecting cardiovascular efficiency
  • C is incorrect: This describes altitude effects, not vascular disease
  • D is incorrect: Iron deficiency causes anaemia, not vascular disease directly

HMS, BM EQ-Bank 874 MC

Anaemia can impact cardiovascular system efficiency. Which of the following best explains why?

  1. Decreased haemoglobin levels reduce oxygen-carrying capacity of blood
  2. Increased blood viscosity restricts blood flow through vessels
  3. Decreased heart rate reduces cardiac output
  4. Increased blood pressure creates resistance in the circulatory system
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\(A\)

Show Worked Solution
  • A is correct. Anaemia is characterised by reduced haemoglobin levels or red blood cell count, which decreases the blood’s capacity to transport oxygen.

Other Options:

  • B is incorrect: Anaemia typically decreases blood viscosity, not increases it.
  • C is incorrect: Anaemia often leads to increased heart rate as a compensatory mechanism.
  • D is incorrect: Anaemia doesn’t directly cause increased blood pressure.

HMS, BM EQ-Bank 873 MC

A mountain climber ascends to 4,500 metres above sea level. Which of the following is an immediate physiological adaptation to the decrease in atmospheric oxygen pressure?

  1. Decrease in heart rate
  2. Increase in haemoglobin concentration
  3. Increase in respiratory rate
  4. Decrease in cardiac output
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\(C\)

Show Worked Solution
  • C is correct. An increase in respiratory rate is an immediate adaptation to compensate for reduced oxygen availability at high altitude.

Other Options:

  • A is incorrect: Heart rate typically increases, not decreases, at high altitude to deliver more oxygen.
  • B is incorrect: Increased haemoglobin concentration is a long-term adaptation to altitude, not immediate.
  • D is incorrect: Cardiac output typically increases, not decreases, at high altitude.

HMS, BM EQ-Bank 872

Evaluate the efficiency of the pulmonary and systemic circulation in facilitating gaseous exchange during rest and exercise.   (12 marks)

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Sample Answer

Evaluation Statement

  • Both pulmonary and systemic circulation demonstrate highly efficient gaseous exchange at rest and exercise.
  • Evaluation based on reserve capacity, adaptability to demand, and exchange effectiveness.

Reserve Capacity at Rest

  • Both circulations maintain substantial reserves during resting conditions.
  • Pulmonary circulation uses only a portion of available alveolar capillaries at rest.
  • Systemic circulation extracts a small percentage of delivered oxygen from blood.
  • Cardiac output remains well below maximum capacity during rest.
  • Evidence strongly indicates optimal efficiency through conservation.
  • Maintaining reserves ensures immediate response capability when needed.
  • Both systems strongly meet efficiency criteria by avoiding unnecessary energy expenditure.

Adaptability to Exercise Demands

  • Both circulations show exceptional responsiveness to increased requirements.
  • Pulmonary capillary recruitment dramatically increases gas exchange surface area.
  • Systemic circulation redistributes blood flow to prioritise active muscles.
  • Oxygen extraction increases significantly in working tissues.
  • Heart rate and stroke volume combine to multiply cardiac output.
  • Evidence indicates highly effective adaptation mechanisms.
  • Response speed and magnitude strongly fulfil exercise requirements.

Gas Exchange Effectiveness

  • Exchange efficiency remains high despite dramatic flow increases during exercise.
  • Pulmonary circulation maintains near-complete oxygen saturation at maximum output.
  • Diffusion time decreases yet remains adequate for gas exchange.
  • Systemic capillaries increase surface area through dilation and recruitment.
  • Temperature and pH changes enhance oxygen release where needed.
  • Evidence demonstrates superior exchange mechanisms throughout exercise intensities.

Final Evaluation

  • Weighing all criteria confirms both circulations operate with exceptional efficiency.
  • Reserve capacity prevents wasteful operation while ensuring response readiness.
  • Adaptability allows precise matching of delivery to demand.
  • Exchange mechanisms maintain effectiveness despite massive flow increases.
  • Minor inefficiencies occur only at extreme exercise intensities.
  • Overall design optimally balances resting economy with exercise capacity.
Show Worked Solution

Sample Answer

Evaluation Statement

  • Both pulmonary and systemic circulation demonstrate highly efficient gaseous exchange at rest and exercise.
  • Evaluation based on reserve capacity, adaptability to demand, and exchange effectiveness.

Reserve Capacity at Rest

  • Both circulations maintain substantial reserves during resting conditions.
  • Pulmonary circulation uses only a portion of available alveolar capillaries at rest.
  • Systemic circulation extracts a small percentage of delivered oxygen from blood.
  • Cardiac output remains well below maximum capacity during rest.
  • Evidence strongly indicates optimal efficiency through conservation.
  • Maintaining reserves ensures immediate response capability when needed.
  • Both systems strongly meet efficiency criteria by avoiding unnecessary energy expenditure.

Adaptability to Exercise Demands

  • Both circulations show exceptional responsiveness to increased requirements.
  • Pulmonary capillary recruitment dramatically increases gas exchange surface area.
  • Systemic circulation redistributes blood flow to prioritise active muscles.
  • Oxygen extraction increases significantly in working tissues.
  • Heart rate and stroke volume combine to multiply cardiac output.
  • Evidence indicates highly effective adaptation mechanisms.
  • Response speed and magnitude strongly fulfil exercise requirements.

Gas Exchange Effectiveness

  • Exchange efficiency remains high despite dramatic flow increases during exercise.
  • Pulmonary circulation maintains near-complete oxygen saturation at maximum output.
  • Diffusion time decreases yet remains adequate for gas exchange.
  • Systemic capillaries increase surface area through dilation and recruitment.
  • Temperature and pH changes enhance oxygen release where needed.
  • Evidence demonstrates superior exchange mechanisms throughout exercise intensities.

Final Evaluation

  • Weighing all criteria confirms both circulations operate with exceptional efficiency.
  • Reserve capacity prevents wasteful operation while ensuring response readiness.
  • Adaptability allows precise matching of delivery to demand.
  • Exchange mechanisms maintain effectiveness despite massive flow increases.
  • Minor inefficiencies occur only at extreme exercise intensities.
  • Overall design optimally balances resting economy with exercise capacity.

HMS, BM EQ-Bank 69

Compare and contrast the effects of peripheral arterial disease and deep vein thrombosis on movement performance, and outline appropriate exercise modifications for each condition.   (5 marks)

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Sample Answer

Similarities:

  • Both conditions affect blood vessels and impair circulation to the legs.
  • Both cause leg pain that limits movement performance.
  • Both require medical clearance before exercise participation.
  • Both need careful monitoring during physical activity.

Differences:

  • PAD affects arteries (oxygen delivery) while DVT affects veins (blood return).
  • PAD pain is predictable during exertion; DVT pain is constant with swelling.
  • PAD allows intermittent exercise; DVT initially restricts all leg movement.
  • PAD pain resolves with rest; DVT poses clot migration risk during activity.

Exercise Modifications for PAD:

  • Use interval training with rest when claudication pain occurs.
  • Maintain moderate intensity (40-60% HRmax).
  • Progress walking duration gradually as tolerance improves.

Exercise Modifications for DVT:

  • Begin with upper body exercises only until medically cleared.
  • Start with very low intensity (20-30% HRmax).
  • Progress slowly from seated to standing to walking activities.
  • Avoid high-impact activities that could dislodge clots.
Show Worked Solution

Sample Answer

Similarities:

  • Both conditions affect blood vessels and impair circulation to the legs.
  • Both cause leg pain that limits movement performance.
  • Both require medical clearance before exercise participation.
  • Both need careful monitoring during physical activity.

Differences:

  • PAD affects arteries (oxygen delivery) while DVT affects veins (blood return).
  • PAD pain is predictable during exertion; DVT pain is constant with swelling.
  • PAD allows intermittent exercise; DVT initially restricts all leg movement.
  • PAD pain resolves with rest; DVT poses clot migration risk during activity.

Exercise Modifications for PAD:

  • Use interval training with rest when claudication pain occurs.
  • Maintain moderate intensity (40-60% HRmax).
  • Progress walking duration gradually as tolerance improves.

Exercise Modifications for DVT:

  • Begin with upper body exercises only until medically cleared.
  • Start with very low intensity (20-30% HRmax).
  • Progress slowly from seated to standing to walking activities.
  • Avoid high-impact activities that could dislodge clots.

HMS, BM EQ-Bank 68

Analyse how iron deficiency anemia impacts both submaximal and maximal exercise performance, and explain two strategies that could be implemented to minimise these effects.   (8 marks)

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Sample Answer

Overview Statement

  • Iron deficiency anaemia significantly impairs exercise performance by reducing oxygen transport capacity.
  • Key components include haemoglobin levels, oxygen delivery, and exercise intensity.
  • The implications differ between submaximal and maximal exercise.

Submaximal Exercise Impact

  • Iron deficiency reduces haemoglobin production, which decreases oxygen-carrying capacity.
  • The cardiovascular system compensates by increasing heart rate at lower exercise intensities.
  • Athletes experience higher heart rates for the same workload compared to healthy individuals.
  • Such compensation reveals how reduced oxygen transport forces the body to work harder.

Maximal Exercise Impact

  • Peak performance depends on maximum oxygen uptake, which directly relates to haemoglobin levels.
  • Lower haemoglobin results in reduced VO₂ max and earlier onset of fatigue.
  • The aerobic system cannot compensate, forcing reliance on anaerobic metabolism.
  • These limitations demonstrate that oxygen transport is the limiting factor in maximal performance.

Strategy 1: Iron Supplementation

  • Daily iron supplements address the root cause by rebuilding haemoglobin stores.
  • Combining iron with vitamin C enhances absorption and recovery speed.
  • This interaction optimises the restoration of oxygen-carrying capacity.

Strategy 2: Training Modification

  • Reducing exercise intensity prevents excessive cardiovascular strain during recovery.
  • Gradual progression allows haemoglobin levels to restore while maintaining fitness.
  • Together, these nutrients optimise the restoration of oxygen-carrying capacity.
Show Worked Solution

Overview Statement

  • Iron deficiency anaemia significantly impairs exercise performance by reducing oxygen transport capacity.
  • Key components include haemoglobin levels, oxygen delivery, and exercise intensity.
  • The implications differ between submaximal and maximal exercise.

Submaximal Exercise Impact

  • Iron deficiency reduces haemoglobin production, which decreases oxygen-carrying capacity.
  • The cardiovascular system compensates by increasing heart rate at lower exercise intensities.
  • Athletes experience higher heart rates for the same workload compared to healthy individuals.
  • Such compensation reveals how reduced oxygen transport forces the body to work harder.

Maximal Exercise Impact

  • Peak performance depends on maximum oxygen uptake, which directly relates to haemoglobin levels.
  • Lower haemoglobin results in reduced VO₂ max and earlier onset of fatigue.
  • The aerobic system cannot compensate, forcing reliance on anaerobic metabolism.
  • These limitations demonstrate that oxygen transport is the limiting factor in maximal performance.

Strategy 1: Iron Supplementation

  • Daily iron supplements address the root cause by rebuilding haemoglobin stores.
  • Combining iron with vitamin C enhances absorption and recovery speed.
  • This interaction optimises the restoration of oxygen-carrying capacity.

Strategy 2: Training Modification

  • Reducing exercise intensity prevents excessive cardiovascular strain during recovery.
  • Gradual progression allows haemoglobin levels to restore while maintaining fitness.
  • Together, these nutrients optimise the restoration of oxygen-carrying capacity.

HMS, BM EQ-Bank 67

Explain how the cardiovascular system adapts to exercise at altitude (2500 metres) over both short-term (24 - 48 hours) and long-term (3+ weeks) periods.   (5 marks)

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Sample Answer

  • Reduced oxygen pressure at altitude triggers immediate cardiovascular responses within 24-48 hours.
  • Heart rate increases because the body needs to circulate blood faster to compensate for lower oxygen content.
  • Cardiac output also rises through increased stroke volume, ensuring tissues receive adequate oxygen supply.
  • These short-term changes maintain oxygen delivery to vital organs despite the thinner air.
  • Breathing rate accelerates in response to chemoreceptors detecting lower blood oxygen levels.
  • After several days, low oxygen levels stimulate the kidneys to produce EPO (erythropoietin).
  • EPO signals bone marrow to increase red blood cell production, which begins the long-term adaptation process.
  • Over 3-4 weeks, red blood cell count rises significantly, enhancing the blood’s oxygen-carrying capacity.
  • Increased haemoglobin concentration results from these higher red blood cell numbers.
  • More haemoglobin molecules enable better oxygen binding from each breath of thin air.
  • Blood vessels in tissues also increase through capillarisation, improving oxygen delivery at the cellular level.
  • Long-term adaptations therefore compensate for reduced atmospheric oxygen, allowing sustained performance at altitude.
Show Worked Solution

Sample Answer

  • Reduced oxygen pressure at altitude triggers immediate cardiovascular responses within 24-48 hours.
  • Heart rate increases because the body needs to circulate blood faster to compensate for lower oxygen content.
  • Cardiac output also rises through increased stroke volume, ensuring tissues receive adequate oxygen supply.
  • These short-term changes maintain oxygen delivery to vital organs despite the thinner air.
  • Breathing rate accelerates in response to chemoreceptors detecting lower blood oxygen levels.
  • After several days, low oxygen levels stimulate the kidneys to produce EPO (erythropoietin).
  • EPO signals bone marrow to increase red blood cell production, which begins the long-term adaptation process.
  • Over 3-4 weeks, red blood cell count rises significantly, enhancing the blood’s oxygen-carrying capacity.
  • Increased haemoglobin concentration results from these higher red blood cell numbers.
  • More haemoglobin molecules enable better oxygen binding from each breath of thin air.
  • Blood vessels in tissues also increase through capillarisation, improving oxygen delivery at the cellular level.
  • Long-term adaptations therefore compensate for reduced atmospheric oxygen, allowing sustained performance at altitude.

HMS, BM EQ-Bank 66 MC

Which vascular condition most directly impacts exercise performance through reduced blood flow to working muscles?

  1. Peripheral arterial disease
  2. Deep vein thrombosis
  3. Varicose veins
  4. High blood pressure
Show Answers Only

\(A\)

Show Worked Solution
  • A is correct: PAD directly reduces blood flow to muscles through arterial narrowing.

Other Options:

  • B is incorrect: DVT affects deep veins, not arterial supply to muscles.
  • C is incorrect: Affects superficial veins, minimal impact on muscle blood flow.
  • D is incorrect: While it affects circulation, doesn’t directly reduce blood flow.

HMS, BM EQ-Bank 65 MC

An athlete with iron deficiency anemia would most likely experience: 

  1. Decreased stroke volume only
  2. Decreased ventilation rate only
  3. Increased blood pressure and decreased cardiac output
  4. Increased heart rate and decreased oxygen carrying capacity
Show Answers Only

\(D\)

Show Worked Solution
  • D is correct. Lower haemoglobin leads to reduced oxygen carrying capacity, heart rate increases to compensate.

Other Options:

  • A is incorrect: Stroke volume isn’t directly affected by iron deficiency.
  • B is incorrect: Capillarisation is a long-term adaptation.
  • C is incorrect: Blood pressure typically decreases in anemia.

HMS, BM EQ-Bank 64 MC

During exercise at high altitude (3000 metres above sea level), which of the following adaptations occurs first in the body?

  1. Increased production of red blood cells
  2. Increased breathing rate and depth
  3. Increased cardiac output
  4. Increased capillarisation
Show Answers Only

\(B\)

Show Worked Solution
  • B is correct: The immediate response to high altitude is hyperventilation to compensate for lower oxygen partial pressure

Other Options:

  • A is incorrect: RBC production (erythropoiesis) takes several days to weeks
  • C is incorrect: While cardiac output increases, it’s secondary to respiratory changes
  • D is incorrect: Capillarisation is a long-term adaptation