SmarterEd

Aussie Maths & Science Teachers: Save your time with SmarterEd

HMS, BM EQ-Bank 772

A 400-metre runner requires significant energy production throughout the race, which typically lasts 45-60 seconds. Explain how the efficiency of ATP production in different energy systems affects the runner's performance throughout the race.   (4 marks)

Show Answers Only

Sample Answer

  • The ATP-PCr system provides immediate energy for the first 2-3 seconds, enabling explosive acceleration from the blocks.
  • By 10 seconds, the glycolytic system becomes predominant, producing ATP rapidly but inefficiently (2 ATP per glucose), causing lactic acid accumulation.
  • Around 30 seconds, the aerobic system contributes more significantly with higher efficiency (36-38 ATP per glucose).
  • In the final 100 metres, glycolytic inefficiency and lactic acid accumulation reduce speed, requiring optimal development of all energy systems for success.
Show Worked Solution

Sample Answer 

  • The ATP-PCr system provides immediate energy for the first 2-3 seconds, enabling explosive acceleration from the blocks.
  • By 10 seconds, the glycolytic system becomes predominant, producing ATP rapidly but inefficiently (2 ATP per glucose), causing lactic acid accumulation.
  • Around 30 seconds, the aerobic system contributes more significantly with higher efficiency (36-38 ATP per glucose).
  • In the final 100 metres, glycolytic inefficiency and lactic acid accumulation reduce speed, requiring optimal development of all energy systems for success.

HMS, BM EQ-Bank 771

Discuss how the ATP-PCr system efficiently produces energy for explosive movements despite its limited capacity for sustained activity.   (4 marks)

Show Answers Only

Sample Answer

  • The ATP-PCr system quickly rebuilds ATP in one step by transferring phosphate from phosphocreatine to ADP, making it the fastest energy production method.
  • This system requires no oxygen or complex chemical processes, allowing immediate energy availability during explosive movements like jumping or sprinting.
  • The system provides approximately 55% of energy during maximal activities lasting 1-10 seconds without producing fatiguing by-products.
  • While highly efficient for immediate needs, capacity is limited by small phosphocreatine storage (120g) in muscle cells.
  • Training enhances efficiency by increasing storage capacity and improving ATP regeneration rates.
Show Worked Solution

Sample Answer

  • The ATP-PCr system quickly rebuilds ATP in one step by transferring phosphate from phosphocreatine to ADP, making it the fastest energy production method.
  • This system requires no oxygen or complex chemical processes, allowing immediate energy availability during explosive movements like jumping or sprinting.
  • The system provides approximately 55% of energy during maximal activities lasting 1-10 seconds without producing fatiguing by-products.
  • While highly efficient for immediate needs, capacity is limited by small phosphocreatine storage (120g) in muscle cells.
  • Training enhances efficiency by increasing storage capacity and improving ATP regeneration rates.

HMS, BM EQ-Bank 770

Analyse the factors that determine which energy system predominates during different phases of a basketball game.   (4 marks)

Show Answers Only

Sample Answer

  • During explosive movements like jumping and sprinting, the ATP-PCr system predominates due to immediate energy demands lasting 2-10 seconds.
  • Fast breaks and sustained defensive pressure rely on the glycolytic system for high-intensity efforts lasting 30-90 seconds.
  • During timeouts and low-intensity periods, the aerobic system becomes predominant, facilitating recovery and ATP-PCr replenishment.
  • Game intensity, player fitness level, and tactical demands influence which system dominates at any given moment.
  • Quarter breaks allow complete energy system recovery, resetting metabolic demands for subsequent periods.
Show Worked Solution

Sample Answer 

  • During explosive movements like jumping and sprinting, the ATP-PCr system predominates due to immediate energy demands lasting 2-10 seconds.
  • Fast breaks and sustained defensive pressure rely on the glycolytic system for high-intensity efforts lasting 30-90 seconds.
  • During timeouts and low-intensity periods, the aerobic system becomes predominant, facilitating recovery and ATP-PCr replenishment.
  • Game intensity, player fitness level, and tactical demands influence which system dominates at any given moment.
  • Quarter breaks allow complete energy system recovery, resetting metabolic demands for subsequent periods.

HMS, BM EQ-Bank 766

A swimmer completes a 200-metre freestyle race and feels significant muscle fatigue in the final 50 metres. Analyse the physiological causes of this fatigue and how it affects performance.   (5 marks)

Show Answers Only

Sample Answer

  • The 200-metre freestyle predominantly uses the glycolytic energy system, with increasing aerobic system contribution toward the end of the race.
  • The primary cause of fatigue is the accumulation of lactic acid in the working muscles, which occurs when production exceeds the rate of removal.
  • Lactic acid accumulation reduces the muscle’s ability to contract forcefully by disrupting calcium binding and cross-bridge formation in the muscle fibres.
  • The increasing acidosis in the muscle environment affects enzyme function, reducing the rate of ATP production through glycolysis.
  • The swimmer experiences a noticeable decline in stroke efficiency and power output as muscle fibre recruitment patterns change in response to fatigue.
  • Coordination and technique deteriorate in the final 50 metres as the central nervous system adapts to the changing muscle fibre capabilities.
  • The perception of effort significantly increases as the body requires increased nervous system activation to maintain the same power output with fatiguing muscles.
Show Worked Solution

Sample Answer 

  • The 200-metre freestyle predominantly uses the glycolytic energy system, with increasing aerobic system contribution toward the end of the race.
  • The primary cause of fatigue is the accumulation of lactic acid in the working muscles, which occurs when production exceeds the rate of removal.
  • Lactic acid accumulation reduces the muscle’s ability to contract forcefully by disrupting calcium binding and cross-bridge formation in the muscle fibres.
  • The increasing acidosis in the muscle environment affects enzyme function, reducing the rate of ATP production through glycolysis.
  • The swimmer experiences a noticeable decline in stroke efficiency and power output as muscle fibre recruitment patterns change in response to fatigue.
  • Coordination and technique deteriorate in the final 50 metres as the central nervous system adapts to the changing muscle fibre capabilities.
  • The perception of effort significantly increases as the body requires increased nervous system activation to maintain the same power output with fatiguing muscles.

HMS, BM EQ-Bank 764 MC

During a 200-metre sprint, an athlete experiences significant fatigue in the final 50 metres. Which of the following best explains the primary cause of this fatigue?

  1. Depletion of phosphocreatine stores
  2. Accumulation of lactic acid in the muscles
  3. Depletion of muscle and liver glycogen
  4. Increased use of fat as a fuel source
Show Answers Only

\(B\)

Show Worked Solution

Consider Option B: 

  • In a 200-metre sprint (lasting approximately 20-30 seconds), the glycolytic system is the predominant energy system.
  • The primary cause of fatigue is the accumulation of lactic acid in the muscles, which occurs when lactic acid is produced faster than it can be removed, interfering with muscle contraction.

Other Options:

  • A is incorrect: While PCr stores are depleted during the sprint, this occurs within the first 10-15 seconds and is not the primary cause of fatigue in the final stages of a 200m race.
  • C is incorrect: Glycogen depletion is a cause of fatigue in longer duration activities (typically > 60 minutes), not in short-duration, high-intensity events like a 200m sprint.
  • D is incorrect: Increased fat metabolism is associated with longer endurance events and is not a cause of fatigue in sprint events; fat metabolism actually increases during recovery, not during the sprint itself.

\(\Rightarrow B\)

HMS, BM EQ-Bank 759

A netball centre typically performs high-intensity bursts of activity throughout a 60-minute game. Describe how the fuel sources used by this athlete would change during different phases of the game.   (6 marks)

Show Answers Only

Sample Answer

  • During explosive movements (jumping, quick directional changes), the centre primarily uses phosphocreatine through the ATP-PCr system for immediate energy.
  • In fast breaks or intense rallies lasting 10-30 seconds, the glycolytic system becomes dominant, using muscle glycogen and blood glucose as fuel sources.
  • During lower intensity periods of the game, the aerobic system predominates, using carbohydrates as the primary fuel source.
  • As the game progresses and glycogen stores become partially depleted, the body increases its reliance on fat metabolism during recovery phases between high-intensity efforts.
  • The interplay of energy systems allows the centre to perform repeated high-intensity efforts throughout the game by recovering phosphocreatine stores during periods of lower intensity.
  • The athlete’s ability to spare glycogen through efficient use of fats during lower intensity phases helps maintain carbohydrate availability for high-intensity efforts in the latter stages of the game.
Show Worked Solution

Sample Answer 

  • During explosive movements (jumping, quick directional changes), the centre primarily uses phosphocreatine through the ATP-PCr system for immediate energy.
  • In fast breaks or intense rallies lasting 10-30 seconds, the glycolytic system becomes dominant, using muscle glycogen and blood glucose as fuel sources.
  • During lower intensity periods of the game, the aerobic system predominates, using carbohydrates as the primary fuel source.
  • As the game progresses and glycogen stores become partially depleted, the body increases its reliance on fat metabolism during recovery phases between high-intensity efforts.
  • The interplay of energy systems allows the centre to perform repeated high-intensity efforts throughout the game by recovering phosphocreatine stores during periods of lower intensity.
  • The athlete’s ability to spare glycogen through efficient use of fats during lower intensity phases helps maintain carbohydrate availability for high-intensity efforts in the latter stages of the game.

HMS, BM EQ-Bank 758

Compare and contrast the efficiency of ATP production in the three energy systems and explain how this affects the duration and intensity of activities where each system is predominant.   (6 marks)

Show Answers Only

Sample Answer

  • ATP-PCr system produces ATP rapidly but has limited stores (approximately 90g of ATP and 120g of PCr), allowing only 10-15 seconds of high-intensity activity.
  • The glycolytic system produces ATP at a moderate rate by partially breaking down glucose anaerobically, supporting 30-45 seconds of high-intensity activity.
  • The aerobic system produces ATP efficiently but more slowly, enabling sustained energy production for activities lasting minutes to hours.
  • The ATP-PCr system supports maximal intensity (>95% of maximum heart rate) activities due to rapid ATP production, but quickly fatigues due to limited PCr stores.
  • The glycolytic system supports high, sub-maximal intensity (85-95% of maximum heart rate) activities but accumulates lactic acid, limiting duration to approximately 30 seconds at peak output.
  • The aerobic system supports sub-maximal intensity (\(\leq\)85% of maximum heart rate) activities due to its efficiency in completely metabolising fuels with oxygen, allowing for sustained energy production.
  • The interplay between rate of ATP production and total ATP production capacity determines the specific performance profile of each energy system.
  • The inverse relationship between ATP production rate and total capacity determines each system’s optimal application to specific activity demands.
Show Worked Solution

Sample Answer 

  • ATP-PCr system produces ATP rapidly but has limited stores (approximately 90g of ATP and 120g of PCr), allowing only 10-15 seconds of high-intensity activity.
  • The glycolytic system produces ATP at a moderate rate by partially breaking down glucose anaerobically, supporting 30-45 seconds of high-intensity activity.
  • The aerobic system produces ATP efficiently but more slowly, enabling sustained energy production for activities lasting minutes to hours.
  • The ATP-PCr system supports maximal intensity (>95% of maximum heart rate) activities due to rapid ATP production, but quickly fatigues due to limited PCr stores.
  • The glycolytic system supports high, sub-maximal intensity (85-95% of maximum heart rate) activities but accumulates lactic acid, limiting duration to approximately 30 seconds at peak output.
  • The aerobic system supports sub-maximal intensity (\(\leq\)85% of maximum heart rate) activities due to its efficiency in completely metabolising fuels with oxygen, allowing for sustained energy production.
  • The interplay between rate of ATP production and total ATP production capacity determines the specific performance profile of each energy system.
  • The inverse relationship between ATP production rate and total capacity determines each system’s optimal application to specific activity demands.

HMS, BM EQ-Bank 757

Identify the fuel sources used by the three energy systems and explain why each energy system uses its particular fuel source(s).   (6 marks)

Show Answers Only

Sample Answer

  • The ATP-PCr system uses phosphocreatine as fuel because PCr can rapidly donate a phosphate group to ADP to reform ATP without requiring oxygen.
  • The glycolytic (lactic acid) system uses carbohydrates in the form of glucose (from blood) and glycogen (stored in muscles) because these can be quickly broken down anaerobically to produce ATP.
  • The aerobic system can use carbohydrates, fats, and proteins as fuel sources because oxygen is available for complete breakdown of these nutrients through cellular respiration pathways.
  • PCr is used for the ATP-PCr system due to its high concentration in muscle cells (five times that of ATP) allowing for quick energy availability.
  • Carbohydrates are the only fuel source that can be metabolised without oxygen, making them essential for the glycolytic system during high-intensity activities.
  • The aerobic system’s ability to use multiple fuel sources, particularly fat during lower intensities, allows for sustained energy production during prolonged activities when oxygen supply meets demand.
Show Worked Solution

Sample Answer 

  • The ATP-PCr system uses phosphocreatine as fuel because PCr can rapidly donate a phosphate group to ADP to reform ATP without requiring oxygen.
  • The glycolytic (lactic acid) system uses carbohydrates in the form of glucose (from blood) and glycogen (stored in muscles) because these can be quickly broken down anaerobically to produce ATP.
  • The aerobic system can use carbohydrates, fats, and proteins as fuel sources because oxygen is available for complete breakdown of these nutrients through cellular respiration pathways.
  • PCr is used for the ATP-PCr system due to its high concentration in muscle cells (five times that of ATP) allowing for quick energy availability.
  • Carbohydrates are the only fuel source that can be metabolised without oxygen, making them essential for the glycolytic system during high-intensity activities.
  • The aerobic system’s ability to use multiple fuel sources, particularly fat during lower intensities, allows for sustained energy production during prolonged activities when oxygen supply meets demand.

HMS, BM EQ-Bank 756 MC

During a marathon, which statement accurately describes what happens to an athlete's fuel usage after approximately 2 hours of running?

  1. The athlete continues to rely exclusively on the ATP-PCr system
  2. The glycolytic system becomes the predominant energy provider
  3. The body shifts from predominantly using glycogen to using more fat
  4. Protein becomes the primary fuel source for ATP production
Show Answers Only

\(C\)

Show Worked Solution
  • C is correct:
    • During a marathon, after approximately 2 hours of running, glycogen stores become depleted.
    • This causes the body to shift from predominantly using glycogen to increasingly relying on fat as a fuel source.

Other Options:

  • A is incorrect: The ATP-PCr system is only predominant for activities lasting 1-10 seconds, not endurance events like marathons.
  • B is incorrect: The glycolytic system is dominant for activities lasting 30-45 seconds, not for prolonged endurance events.
  • D is incorrect: While protein can be used as a fuel source in the aerobic system, it is not the primary fuel source, even in prolonged exercise; fat becomes the primary alternative fuel once glycogen is depleted.

HMS, BM EQ-Bank 755 MC

During a 100-metre sprint, an athlete primarily uses which energy system and fuel source in the first 2 seconds?

  1. ATP-PCr system using phosphocreatine
  2. Glycolytic system using glucose
  3. Aerobic system using carbohydrates
  4. Aerobic system using fats
Show Answers Only

\(A\)

Show Worked Solution
  • A is correct:
    • In the first 2 seconds of a 100-metre sprint, the body relies on the ATP-PCr system.
    • This system uses phosphocreatine as its fuel source to rapidly generate ATP for the explosive muscular contraction needed at the start of the sprint.

Other Options:

  • B is incorrect: The glycolytic system becomes predominant after approximately 10 seconds once PCr supplies begin to deplete.
  • C is incorrect: The aerobic system using carbohydrates is not the predominant energy system during the initial explosive phase of a sprint.
  • D is incorrect: The aerobic system using fats is used primarily during longer duration, lower intensity activities, not the explosive start of a sprint.

HMS, BM EQ-Bank 301 MC

A sports scientist is designing interval training programs targeting different energy systems. Which combination of intensity, work interval and recovery period would MOST effectively develop the glycolytic energy system?

  1. 95-100% maximum effort, 5-10 second work intervals, 3-5 minute recovery periods
  2. 75-85% maximum effort, 3-5 minute work intervals, 1-2 minute recovery periods
  3. 85-95% maximum effort, 30-90 second work intervals, 1-3 minute recovery periods
  4. 60-75% maximum effort, 10-20 minute work intervals, 2-3 minute recovery periods
Show Answers Only

\(C\)

Show Worked Solution
  • C is correct:
    • The glycolytic (lactic acid) system is optimally trained using 85-95% intensity with 30-90 second work intervals and 1-3 minute recovery periods.
    • This creates the optimal stimulus for lactate production and clearance adaptations.

Other Options:

  • A is incorrect: 5-10 second intervals with long recovery primarily target the ATP-PCr system, not the glycolytic system.
  • B is incorrect: 3-5 minute work intervals with shorter recovery shifts training toward the aerobic system rather than focusing on glycolytic development.
  • D is incorrect: 60-75% intensity with 10-20 minute intervals represents aerobic endurance training that won’t effectively develop the glycolytic system.

HMS, BM EQ-Bank 208 MC

A rower is competing in a 2000 m race lasting 6-8 minutes. What is the predominant energy system used?

  1. ATP-PCr only
  2. Lactic acid only
  3. Aerobic only
  4. Combination of lactic acid and aerobic
Show Answers Only

\(D\)

Show Worked Solution
  • D is correct: Duration requires both systems working together

Other Options:

  • A is incorrect: Duration too long
  • B is incorrect: Cannot sustain effort
  • C is incorrect: Intensity too high for aerobic only

HMS, BM EQ-Bank 206 MC

A netball player completes a 40-minute game. Which energy system is MOST predominantly used?

  1. ATP-PCr
  2. Lactic acid
  3. Aerobic
  4. ATP-PCr and lactic acid combined
Show Answers Only

\(C\)

Show Worked Solution
  • C is correct: Netball requires sustained effort over 40 minutes requiring oxygen.

Other Options:

  • A is incorrect: Too short duration
  • B is incorrect: Not sustained enough duration
  • D is incorrect: Combined systems but not predominant

HMS, BM EQ-Bank 191

A swimmer performs a 200 metre freestyle race.

Explain how TWO different energy systems contribute to fatigue during this event.   (4 marks)

Show Answers Only

Sample Answer

ATP-PCr System

  • In the first 10-15 seconds, the ATP-PCr system rapidly depletes its phosphagen stores, reducing the power output available for the explosive start and initial sprint phase, forcing reliance on less efficient energy systems for immediate power generation.

Glycolytic System

  • The glycolytic system dominates throughout most of the race, causing progressive lactic acid accumulation that decreases muscle contraction efficiency and interferes with enzyme function, leading to the characteristic “burning” sensation and pace decline.
Show Worked Solution

Sample Answer

ATP-PCr System

  • In the first 10-15 seconds, the ATP-PCr system rapidly depletes its phosphagen stores, reducing the power output available for the explosive start and initial sprint phase, forcing reliance on less efficient energy systems for immediate power generation.

Glycolytic System

  • The glycolytic system dominates throughout most of the race, causing progressive lactic acid accumulation that decreases muscle contraction efficiency and interferes with enzyme function, leading to the characteristic “burning” sensation and pace decline.

HMS, BM EQ-Bank 190

During a summer time beach volleyball tournament, an athlete begins to experience fatigue during their third game of the day.

Identify TWO causes of fatigue and explain their impact on performance.   (3 marks)

Show Answers Only

Sample Answer – Any TWO of the following

Glycogen depletion

  • The depletion of muscle glycogen throughout multiple games reduces energy availability for explosive movements like jumping and diving, leading to decreased power output in attacking plays.

Dehydration

  • Progressive dehydration occurs during play in hot conditions, causing a decrease in blood plasma volume which reduces oxygen delivery to working muscles and impairs coordination for precise ball skills.

Electrolyte imbalance

  • Electrolyte imbalance from excessive sweating in hot conditions leads to altered nerve impulse transmission and muscle contraction efficiency, resulting in cramping and reduced reaction times for defensive plays.

Lactic acid accumulation

  • Accumulation of lactic acid from repeated high-intensity rallies causes muscle pH to decrease, interfering with enzyme function and muscle contraction processes, leading to reduced jumping height and slower court movement.
Show Worked Solution

Sample Answer – Any TWO of the following

Glycogen depletion

  • The depletion of muscle glycogen throughout multiple games reduces energy availability for explosive movements like jumping and diving, leading to decreased power output in attacking plays.

Dehydration

  • Progressive dehydration occurs during play in hot conditions, causing a decrease in blood plasma volume which reduces oxygen delivery to working muscles and impairs coordination for precise ball skills.

Electrolyte imbalance

  • Electrolyte imbalance from excessive sweating in hot conditions leads to altered nerve impulse transmission and muscle contraction efficiency, resulting in cramping and reduced reaction times for defensive plays.

Lactic acid accumulation

  • Accumulation of lactic acid from repeated high-intensity rallies causes muscle pH to decrease, interfering with enzyme function and muscle contraction processes, leading to reduced jumping height and slower court movement.

HMS, BM EQ-Bank 189

Explain how different causes of fatigue affect performance in a 2-minute rowing sprint.   (5 marks)

Show Answers Only

Sample Answer

  • During the initial explosive start, ATP-PCr stores become rapidly depleted within 10 seconds, resulting in an immediate decrease in power output for the rowing stroke.
  • The accumulation of lactic acid from the dominant glycolytic system causes the blood pH to drop significantly, interfering with the efficiency of muscle contractions and power generation through the middle section.
  • Local muscle glycogen stores begin depleting as the intensity continues, reducing the availability of immediate energy for the working muscles in the latter stages.
  • Neural fatigue progressively reduces the efficiency of muscle fibre recruitment, particularly affecting the large muscle groups required for maintaining proper rowing technique.
  • The psychological impact of fatigue affects technique execution and power application, leading to a decline in stroke efficiency and overall performance output.
Show Worked Solution

Sample Answer

  • During the initial explosive start, ATP-PCr stores become rapidly depleted within 10 seconds, resulting in an immediate decrease in power output for the rowing stroke.
  • The accumulation of lactic acid from the dominant glycolytic system causes the blood pH to drop significantly, interfering with the efficiency of muscle contractions and power generation through the middle section.
  • Local muscle glycogen stores begin depleting as the intensity continues, reducing the availability of immediate energy for the working muscles in the latter stages.
  • Neural fatigue progressively reduces the efficiency of muscle fibre recruitment, particularly affecting the large muscle groups required for maintaining proper rowing technique.
  • The psychological impact of fatigue affects technique execution and power application, leading to a decline in stroke efficiency and overall performance output.

HMS, BM EQ-Bank 184

Analyse how the three energy systems interact to provide energy during a 1500 metre race.   (8 marks)

Show Answers Only

Sample Answer

  • As the race begins, the ATP-PCr system provides immediate energy for the explosive start and initial acceleration to race pace within the first 10 seconds.
  • The lactic acid system then becomes increasingly important during the first 400 metres as runners establish position and settle into race pace, contributing approximately 15% of energy requirements.
  • The aerobic system becomes the dominant energy provider after the first lap, delivering approximately 85% of energy needs for the remainder of the race through oxidative phosphorylation.
  • During tactical surges or when overtaking competitors, there is increased contribution from the lactic acid system while the aerobic system continues to operate.
  • Brief reductions in pace allow partial replenishment of ATP-PCr stores which can then be utilised for short bursts of acceleration when responding to competitors’ moves.
  • Accumulated lactic acid from anaerobic glycolysis may begin to impact performance in the final stages of the race if the pace has been too aggressive.
  • The aerobic system’s efficiency in providing energy while clearing metabolic waste products becomes crucial in maintaining race pace through the middle stages.
  • Throughout the race, all three energy systems operate simultaneously with their relative contributions shifting based on pace changes and tactical demands of the race.
Show Worked Solution

Sample Answer

  • As the race begins, the ATP-PCr system provides immediate energy for the explosive start and initial acceleration to race pace within the first 10 seconds.
  • The lactic acid system then becomes increasingly important during the first 400 metres as runners establish position and settle into race pace, contributing approximately 15% of energy requirements.
  • The aerobic system becomes the dominant energy provider after the first lap, delivering approximately 85% of energy needs for the remainder of the race through oxidative phosphorylation.
  • During tactical surges or when overtaking competitors, there is increased contribution from the lactic acid system while the aerobic system continues to operate.
  • Brief reductions in pace allow partial replenishment of ATP-PCr stores which can then be utilised for short bursts of acceleration when responding to competitors’ moves.
  • Accumulated lactic acid from anaerobic glycolysis may begin to impact performance in the final stages of the race if the pace has been too aggressive.
  • The aerobic system’s efficiency in providing energy while clearing metabolic waste products becomes crucial in maintaining race pace through the middle stages.
  • Throughout the race, all three energy systems operate simultaneously with their relative contributions shifting based on pace changes and tactical demands of the race.

HMS, BM EQ-Bank 181

Explain how the lactic acid system contributes to energy production during a 200 m sprint.   (4 marks)

Show Answers Only

Sample Answer

  • During the 200 m sprint, glucose is broken down without oxygen through glycolysis to produce ATP for sustained high-intensity muscle contractions.
  • This anaerobic process creates lactic acid as a by-product which accumulates in the working muscles causing fatigue.
  • The lactic acid system can maintain high-intensity performance for up to 60-90 seconds before waste products significantly impair muscle function.
  • As a 200 m sprint typically takes 20-25 seconds, this system provides the majority of energy required after the initial ATP-PCr stores are depleted at around 10 seconds.
Show Worked Solution

Sample Answer

  • During the 200 m sprint, glucose is broken down without oxygen through glycolysis to produce ATP for sustained high-intensity muscle contractions.
  • This anaerobic process creates lactic acid as a by-product which accumulates in the working muscles causing fatigue.
  • The lactic acid system can maintain high-intensity performance for up to 60-90 seconds before waste products significantly impair muscle function.
  • As a 200 m sprint typically takes 20-25 seconds, this system provides the majority of energy required after the initial ATP-PCr stores are depleted at around 10 seconds.

HMS, BM EQ-Bank 178 MC

A netball player performs a 30-second high-intensity defensive sequence followed by 2 minutes of moderate-intensity play.

Which energy system sequence best represents this activity pattern?

  1. ATP-PCr → Aerobic → Lactic Acid
  2. Lactic Acid → ATP-PCr → Aerobic
  3. ATP-PCr → Lactic Acid → Aerobic
  4. Aerobic → ATP-PCr → Lactic Acid
Show Answers Only

\(C\)

Show Worked Solution
  • C is correct:
    • ATP-PCr is first used for the immediate high-intensity defensive moves (0-10 seconds)
    • then the lactic acid system is used for continued high-intensity work (10-30 seconds)
    • finally the aerobic system is relied upon for the moderate-intensity play (30 seconds onwards).

Other Options:

  • A is incorrect: Aerobic would not be the second system engaged
  • B is incorrect: Lactic acid system would not be first in this sequence
  • D is incorrect: Aerobic would not be first for high-intensity work

HMS, BM EQ-Bank 177

Explain how the rate of recovery differs between anaerobic energy systems, and impacts performance.   (4 marks)

Show Answers Only

Sample Answer

  • ATP-PCr system demonstrates rapid initial recovery with 70% replenishment within 30 seconds, allowing repeated short bursts of maximal power in sports like gymnastics or sprinting.
  • Glycolytic system requires significantly longer recovery periods of 3-5 minutes due to lactate clearance needs, affecting an athlete’s ability to maintain intensity in 400m running.
  • Recovery rates create distinct limitations where short recovery compromises ATP-PCr power and insufficient glycolytic recovery leads to deteriorating performance through accumulated fatigue.
  • Both systems improve recovery efficiency through training adaptations, with ATP-PCr enhancing phosphocreatine resynthesis and glycolytic developing better lactate buffering capacity.
Show Worked Solution

Sample Answer

  • ATP-PCr system demonstrates rapid initial recovery with 70% replenishment within 30 seconds, allowing repeated short bursts of maximal power in sports like gymnastics or sprinting.
  • Glycolytic system requires significantly longer recovery periods of 3-5 minutes due to lactate clearance needs, affecting an athlete’s ability to maintain intensity in 400m running.
  • Recovery rates create distinct limitations where short recovery compromises ATP-PCr power and insufficient glycolytic recovery leads to deteriorating performance through accumulated fatigue.
  • Both systems improve recovery efficiency through training adaptations, with ATP-PCr enhancing phosphocreatine resynthesis and glycolytic developing better lactate buffering capacity.

HMS, BM EQ-Bank 175

Outline how active versus passive recovery affects the rate of lactate removal following high-intensity exercise.   (3 marks)

Show Answers Only

Sample Answer

  • Active recovery maintains elevated blood flow and heart rate, which accelerates lactate removal through increased oxygen delivery to working muscles.
  • Passive recovery results in slower lactate removal as reduced blood flow and oxygen delivery limit the rate of metabolic waste clearance.
  • Active recovery at 30-40% intensity is optimal for lactate clearance as it balances increased blood flow with sufficient oxygen availability for aerobic metabolism.
Show Worked Solution

Sample Answer

  • Active recovery maintains elevated blood flow and heart rate, which accelerates lactate removal through increased oxygen delivery to working muscles.
  • Passive recovery results in slower lactate removal as reduced blood flow and oxygen delivery limit the rate of metabolic waste clearance.
  • Active recovery at 30-40% intensity is optimal for lactate clearance as it balances increased blood flow with sufficient oxygen availability for aerobic metabolism.

HMS, BM EQ-Bank 174 MC

An athlete trains using different intensities across a session. Which energy system requires the LONGEST recovery period?

  1. ATP-PCr system after a 10-second sprint
  2. Glycolytic system after a 60-second effort
  3. Aerobic system after a 10-minute effort
  4. ATP-PCr and Glycolytic combined after a 20-second effort
Show Answers Only

\(B\)

Show Worked Solution
  • B is correct: A 60-second maximal glycolytic effort produces high lactate levels requiring extended recovery time for acid-base balance restoration and lactate removal.

Other Options:

  • A is incorrect: ATP-PCr recovers relatively quickly
  • C is incorrect: Aerobic system recovers during activity
  • D is incorrect: Combined systems don’t extend recovery time

HMS, BM EQ-Bank 173 MC

During high-intensity interval training, an athlete performs 400 metre sprints. Which recovery period would be most appropriate to allow lactate clearance between efforts?

  1. 30 seconds active recovery
  2. 1 minute passive recovery
  3. 3 minutes active recovery
  4. 5 minutes passive recovery
Show Answers Only

\(C\)

Show Worked Solution
  • C is correct: Active recovery aids lactate removal within optimal timeframe

Other Options:

  • A is incorrect: Insufficient time for lactate clearance
  • B is incorrect: Passive recovery less effective for lactate removal
  • D is incorrect: Unnecessarily long recovery period

HMS, BM EQ-Bank 172 MC

A basketball player performs repeated 15-second full court sprints. What is the MINIMUM rest period needed for substantial ATP-PCr recovery?

  1. 15 seconds
  2. 30 seconds
  3. 60 seconds
  4. 120 seconds
Show Answers Only

\(B\)

Show Worked Solution
  • B is correct: 70% of ATP-PCr stores are replenished within 30 seconds, providing sufficient recovery for another maximal effort.

Other Options:

  • A is incorrect: Insufficient recovery time
  • C and D are incorrect: Longer than needed for substantial recovery

HMS, BM EQ-Bank 171

Compare the duration limitations of the ATP-PCr and Glycolytic energy systems.   (4 marks)

Show Answers Only

Keyword – “Compare”: Show how things are similar or different.

Sample Answer

  • ATP-PCr system is limited to 0-10 seconds maximum duration before phosphocreatine stores deplete, making it suitable only for explosive actions like vertical jumps or short sprints.
  • Glycolytic system sustains high-intensity activity for 30-90 seconds before lactic acid accumulation causes fatigue, supporting activities like 400m sprints or intensive game sequences.
  • ATP-PCr requires approximately 3 minutes for full recovery between maximal efforts, with 70% regeneration occurring in the first 30 seconds due to efficient phosphate resynthesis.
  • Glycolytic system needs 5-8 minutes for complete recovery as lactate must be removed from muscles and blood pH restored, limiting repeated high-intensity efforts within this timeframe.
  • Both systems have specific duration constraints affecting training design.
Show Worked Solution

Keyword – “Compare”: Show how things are similar or different.

Sample Answer

  • ATP-PCr system is limited to 0-10 seconds maximum duration before phosphocreatine stores deplete, making it suitable only for explosive actions like vertical jumps or short sprints.
  • Glycolytic system sustains high-intensity activity for 30-90 seconds before lactic acid accumulation causes fatigue, supporting activities like 400m sprints or intensive game sequences.
  • ATP-PCr requires approximately 3 minutes for full recovery between maximal efforts, with 70% regeneration occurring in the first 30 seconds due to efficient phosphate resynthesis.
  • Glycolytic system needs 5-8 minutes for complete recovery as lactate must be removed from muscles and blood pH restored, limiting repeated high-intensity efforts within this timeframe.
  • Both systems have specific duration constraints affecting training design.

HMS, BM EQ-Bank 169

Explain how duration affects the body's utilisation of the three energy systems during a 400 m sprint.   (3 marks)

Show Answers Only

Sample Answer

  • Initial 0-10 seconds utilises ATP-PCr system for immediate energy at race start
  • As duration extends to 10-45 seconds, glycolytic system becomes predominant providing energy through glucose breakdown
  • Final stages see increased aerobic contribution as duration approaches 60 seconds though glycolytic remains primary
  • Systems overlap throughout race duration but predominance shifts based on time demands
Show Worked Solution

Sample Answer

  • Initial 0-10 seconds utilises ATP-PCr system for immediate energy at race start
  • As duration extends to 10-45 seconds, glycolytic system becomes predominant providing energy through glucose breakdown
  • Final stages see increased aerobic contribution as duration approaches 60 seconds though glycolytic remains primary
  • Systems overlap throughout race duration but predominance shifts based on time demand

HMS, BM EQ-Bank 168 MC

During a marathon run lasting over 3 hours, which energy system contribution would be most accurate?

  1. 70% aerobic, 20% glycolytic, 10% ATP-PCr
  2. 95% aerobic, 4% glycolytic, 1% ATP-PCr
  3. 85% aerobic, 10% glycolytic, 5% ATP-PCr
  4. 60% aerobic, 30% glycolytic, 10% ATP-PCr
Show Answers Only

\(B\)

Show Worked Solution
  • B is correct:
    • Marathon running is an endurance activity requiring sustained energy production (95% aerobic) over 3+ hours.
    • This can only be achieved through the aerobic system’s efficient use of oxygen and fuel substrates.

Other Options: 

  • A is incorrect: Glycolytic contribution too high for endurance event
  • C is incorrect: Percentages don’t reflect true duration demands
  • D is incorrect: Anaerobic contribution too high for marathon

HMS, BM EQ-Bank 164

Analyse how different intensities of training can affect energy system adaptations.   (5 marks)

Show Answers Only

Sample Answer

  • HIIT increases ATP-PCr stores and phosphocreatine enzyme activity within muscle cells, enhancing the capacity for immediate energy production during explosive movements and repeated short-duration efforts.
  • Training at lactate threshold intensity improves the body’s lactate buffering capacity and tolerance to lactic acid accumulation, enabling athletes to maintain higher intensities for longer periods when relying on glycolytic system energy production.
  • Aerobic training at moderate intensities increases mitochondrial density and size within muscle fibres, improving oxygen utilisation efficiency and the capacity for sustained ATP production through complete glucose and fat breakdown.
  • Varied intensity training programs improve overall energy system efficiency and enhance the smooth transition and interaction between different energy systems during changing exercise demands and intensities.
  • Sport-specific intensity training leads to targeted metabolic adaptations within the predominantly used energy system, such as increased glycolytic enzyme concentration in sprinters or enhanced aerobic capacity in endurance athletes.
  • The principle of training specificity ensures that energy system adaptations closely match the intensity demands and duration characteristics of the athlete’s competitive performance requirements.
Show Worked Solution

Sample Answer

  • HIIT increases ATP-PCr stores and phosphocreatine enzyme activity within muscle cells, enhancing the capacity for immediate energy production during explosive movements and repeated short-duration efforts.
  • Training at lactate threshold intensity improves the body’s lactate buffering capacity and tolerance to lactic acid accumulation, enabling athletes to maintain higher intensities for longer periods when relying on glycolytic system energy production.
  • Aerobic training at moderate intensities increases mitochondrial density and size within muscle fibres, improving oxygen utilisation efficiency and the capacity for sustained ATP production through complete glucose and fat breakdown.
  • Varied intensity training programs improve overall energy system efficiency and enhance the smooth transition and interaction between different energy systems during changing exercise demands and intensities.
  • Sport-specific intensity training leads to targeted metabolic adaptations within the predominantly used energy system, such as increased glycolytic enzyme concentration in sprinters or enhanced aerobic capacity in endurance athletes.
  • The principle of training specificity ensures that energy system adaptations closely match the intensity demands and duration characteristics of the athlete’s competitive performance requirements.

HMS, BM EQ-Bank 162 MC

A tennis player is in a rally lasting 45 seconds at moderate-high intensity. Which energy system sequence best represents their energy production?

  1. Glycolytic → ATP-PCr → Aerobic
  2. Aerobic → ATP-PCr → Glycolytic
  3. ATP-PCr → Aerobic → Glycolytic
  4. ATP-PCr → Glycolytic → Aerobic
Show Answers Only

\(D\)

Show Worked Solution
  • D is correct: Shows the natural progression of energy systems as intensity/duration increases

Other Options:

  • A is incorrect: ATP-PCr is the initial energy system
  • B is incorrect: ATP-PCr is the initial energy system and aerobic takes longer to become predominant
  • C is incorrect: Glycolytic precedes Aerobic for moderate-high intensity

HMS, BM EQ-Bank 161 MC

During a 400 m race at high intensity, an athlete experiences muscular fatigue. What is the main cause?

  1. Depletion of glycogen stores
  2. Accumulation of lactic acid
  3. Lack of oxygen
  4. Depletion of creatine phosphate
Show Answers Only

\(B\)

Show Worked Solution
  • B is correct: Lactic acid accumulation during high intensity glycolytic system use causes fatigue

Other Options:

  • A is incorrect: Glycogen depletion occurs over longer duration events
  • C is incorrect: Oxygen debt occurs after exercise completion
  • D is incorrect: CP depletion occurs in shorter activities under 10 seconds

HMS, BM EQ-Bank 159

Explain how the rate of ATP production affects an athlete's performance in a 200 metre sprint.  (6 marks)

Show Answers Only

Sample Answer

  • The ATP-PCr system produces ATP rapidly from creatine phosphate breakdown to power explosive acceleration in the first 10-15 metres of the race, providing immediate energy without oxygen requirements for maximal power output.
  • As phosphocreatine stores deplete within 10-15 seconds, the glycolytic system becomes the main ATP producer through rapid glucose and glycogen breakdown, allowing continued high-intensity effort through the middle section of the race.
  • The aerobic system contributes minimal ATP due to its slow production rate compared to anaerobic systems and the significant oxygen deficit created during maximal sprinting intensity at race pace.
  • The glycolytic system’s rapid ATP production rate creates lactic acid as a metabolic by-product, which begins to accumulate in working muscles and interfere with continued energy production processes.
  • Muscle enzyme function and contraction efficiency become progressively impaired as lactic acid accumulates, causing muscle pH to decrease and reducing the overall rate of ATP production available for muscle contraction.
  • Running speed decreases significantly in the final 50 metres as the declining rate of ATP production from fatigued energy systems can no longer support maximal sprint intensity, forcing pace reduction despite tactical demands.
Show Worked Solution

Sample Answer

  • The ATP-PCr system produces ATP rapidly from creatine phosphate breakdown to power explosive acceleration in the first 10-15 metres of the race, providing immediate energy without oxygen requirements for maximal power output.
  • As phosphocreatine stores deplete within 10-15 seconds, the glycolytic system becomes the main ATP producer through rapid glucose and glycogen breakdown, allowing continued high-intensity effort through the middle section of the race.
  • The aerobic system contributes minimal ATP due to its slow production rate compared to anaerobic systems and the significant oxygen deficit created during maximal sprinting intensity at race pace.
  • The glycolytic system’s rapid ATP production rate creates lactic acid as a metabolic by-product, which begins to accumulate in working muscles and interfere with continued energy production processes.
  • Muscle enzyme function and contraction efficiency become progressively impaired as lactic acid accumulates, causing muscle pH to decrease and reducing the overall rate of ATP production available for muscle contraction.
  • Running speed decreases significantly in the final 50 metres as the declining rate of ATP production from fatigued energy systems can no longer support maximal sprint intensity, forcing pace reduction despite tactical demands.

HMS, BM EQ-Bank 155 MC

Which statement best explains why the aerobic system produces the most ATP?

  1. It has the fastest reaction rate
  2. It uses more glucose molecules
  3. It doesn't produce waste products
  4. It completes glucose breakdown
Show Answers Only

\(D\)

Show Worked Solution
  • D is correct: The aerobic system completely breaks down glucose and allows for maximum ATP extraction (36-38 ATP) from each glucose molecule. Other systems only partially break down glucose.

Other Options:

  • A is incorrect: Aerobic system has slowest reaction rate of all 3 energy systems. ATP-PCr is fastest, followed by glycolytic then aerobic.
  • B is incorrect: The amount of glucose molecules used is not the determining factor in ATP production. It’s the completeness of the breakdown process.
  • C is incorrect: Aerobic system produces waste products (CO2 and H2O).

HMS, BM EQ-Bank 154 MC

During a 400m sprint, what amount of ATP would ONE glucose molecule produce through the glycolytic system?

  1. 1-2 ATP
  2. 2-3 ATP
  3. 8-10 ATP
  4. 36-38 ATP
Show Answers Only

\(B\)

Show Worked Solution

 

  • B is correct: Net ATP yield from glycolysis

Other Options:

  • A is incorrect: Too low for glycolysis
  • C is incorrect: Too high for anaerobic glycolysis
  • D is incorrect: This is aerobic system yield

HMS, BM EQ-Bank 151

Analyse how the availability of different fuel sources affects an athlete's performance in a 90-minute soccer match.   (6 marks)

Show Answers Only

Sample Answer

  • The ATP-PCr system provides immediate energy for explosive sprints and tackles in the first few seconds of each high-intensity effort through stored creatine phosphate.
  • During the match, muscle glycogen serves as the primary fuel source, supporting both aerobic activity for general play and anaerobic bursts for sprinting or rapid directional changes.
  • As the match progresses and muscle glycogen becomes depleted, the body increasingly relies on fatty acid oxidation for energy production during lower intensity periods of play.
  • The maintenance of blood glucose levels through liver glycogen breakdown becomes crucial in the latter stages of the match to sustain both physical and mental performance.
  • Players often experience fatigue in the final 15 – 20 minutes of the match due to significant depletion of muscle glycogen stores, resulting in reduced sprint capacity and skill execution.
  • Athletes who engage in carbohydrate loading protocols prior to the match can increase their muscle glycogen stores by up to 50%, thereby delaying the onset of fatigue and maintaining performance intensity throughout the full 90 minutes.
Show Worked Solution

Sample Answer

  • The ATP-PCr system provides immediate energy for explosive sprints and tackles in the first few seconds of each high-intensity effort through stored creatine phosphate.
  • During the match, muscle glycogen serves as the primary fuel source, supporting both aerobic activity for general play and anaerobic bursts for sprinting or rapid directional changes.
  • As the match progresses and muscle glycogen becomes depleted, the body increasingly relies on fatty acid oxidation for energy production during lower intensity periods of play.
  • The maintenance of blood glucose levels through liver glycogen breakdown becomes crucial in the latter stages of the match to sustain both physical and mental performance.
  • Players often experience fatigue in the final 15 – 20 minutes of the match due to significant depletion of muscle glycogen stores, resulting in reduced sprint capacity and skill execution.
  • Athletes who engage in carbohydrate loading protocols prior to the match can increase their muscle glycogen stores by up to 50%, thereby delaying the onset of fatigue and maintaining performance intensity throughout the full 90 minutes.

HMS, BM EQ-Bank 150

Explain how glucose is used differently as a fuel source in the glycolytic and aerobic energy systems.   (4 marks)

Show Answers Only

Sample Answer

Glycolytic System:

  • Breaks down glucose without oxygen in sarcoplasm
  • Produces 2 – 3 ATP molecules through rapid glycolysis
  • Results in lactic acid as by-product
  • Powers high-intensity exercise 10 – 60 seconds

Aerobic System:

  • Complete glucose breakdown with oxygen in mitochondria
  • Produces 36 – 38 ATP through Krebs cycle/electron transport chain
  • Results in CO2 and H2O as by-products
  • Powers prolonged exercise 2+ minutes

Summary

  • Glycolytic system sacrifices ATP yield for speed, while aerobic system maximises ATP production through complete glucose oxidation.
Show Worked Solution

Sample Answer

Glycolytic System:

  • Breaks down glucose without oxygen in sarcoplasm
  • Produces 2 – 3 ATP molecules through rapid glycolysis
  • Results in lactic acid as by-product
  • Powers high-intensity exercise 10 – 60 seconds

Aerobic System:

  • Complete glucose breakdown with oxygen in mitochondria
  • Produces 36 – 38 ATP through Krebs cycle/electron transport chain
  • Results in CO2 and H2O as by-products
  • Powers prolonged exercise 2+ minutes

Summary

  • Glycolytic system sacrifices ATP yield for speed, while aerobic system maximises ATP production through complete glucose oxidation.

HMS, BM EQ-Bank 149 MC

Which statement best describes why fatty acids cannot be the primary fuel source for high-intensity exercise?

  1. Fatty acids require too much oxygen for breakdown
  2. Fatty acids are not stored in muscle tissue
  3. Fatty acids produce less ATP than glucose
  4. Fatty acids are too complex to break down quickly
Show Answers Only

\(A\)

Show Worked Solution
  • A is correct: Fatty acid metabolism requires significant oxygen

Other Options:

  • B is incorrect: Fatty acids are stored as intramuscular triglycerides
  • C is incorrect: Fatty acids actually produce more ATP than glucose
  • D is incorrect: Complexity isn’t the primary limitation

HMS, BM EQ-Bank 148 MC

A marathon runner hits "the wall" after 30 kilometres of running. Which fuel source has most likely been depleted?

  1. Creatine phosphate
  2. Blood glucose
  3. Muscle glycogen
  4. Plasma proteins
Show Answers Only

\(C\)

Show Worked Solution
  • C is correct: Muscle glycogen depletion occurs in prolonged exercise

Other Options:

  • A is incorrect: CP depletion occurs in seconds
  • B is incorrect: Blood glucose is maintained through liver glycogen
  • D is incorrect: Proteins are not a primary fuel source

HMS, BM EQ-Bank 147

Describe the relationship between energy system efficiency and ATP production.   (5 marks)

Show Answers Only

Answers could include/expand on any of the following points:

  • ATP-PCr most efficient for immediate energy but limited ATP yield (1-2 ATP).
  • Glycolytic system produces moderate ATP (2-3 ATP) but accumulates lactic acid.
  • Aerobic system most efficient producing 36-38 ATP molecules per glucose molecule.
  • Efficiency decreases as intensity increases due to oxygen availability.
  • ATP production rate highest in ATP-PCr but duration limited by CP stores.
Show Worked Solution

Answers could include/expand on any of the following points:

  • ATP-PCr most efficient for immediate energy but limited ATP yield (1-2 ATP).
  • Glycolytic system produces moderate ATP (2-3 ATP) but accumulates lactic acid.
  • Aerobic system most efficient producing 36-38 ATP molecules per glucose molecule.
  • Efficiency decreases as intensity increases due to oxygen availability.
  • ATP production rate highest in ATP-PCr but duration limited by CP stores.

HMS, BM EQ-Bank 146

Explain how the three energy systems interplay during a 400 metre sprint race.   (6 marks)

Show Answers Only

Sample Answer

First 2-3 seconds:

  • The ATP-PCr system provides immediate energy through rapid breakdown of stored phosphocreatine, enabling explosive acceleration from starting blocks without oxygen requirement.

Seconds 3-15:

  • ATP-PCr system remains dominant but begins depleting, with the runner achieving peak velocity as this system provides the highest rate of ATP production for maximum power output.

Seconds 15-30:

  • Glycolytic system becomes predominant as ATP-PCr stores deplete, breaking down muscle glycogen to produce ATP anaerobically, resulting in rapid lactic acid formation.

Seconds 30-45:

  • Continued dominance of glycolytic system with increasing aerobic contribution as oxygen becomes more available, though anaerobic glycolysis still provides majority of energy.

Final 15 seconds:

  • All three systems operate simultaneously with glycolytic system still dominant, but accumulating lactic acid begins interfering with muscle contraction, causing performance decline.

System integration:

  • The transition between systems is gradual rather than distinct, with optimal 400 metre performance requiring efficient switching between energy pathways and the ability to tolerate high lactate levels.

Recovery phase:

  • Post-race recovery involves replenishing ATP-PCr stores (50% within 30 seconds), removing accumulated lactate through aerobic metabolism, and restoring muscle pH levels.
Show Worked Solution

Sample Answer

First 2-3 seconds:

  • The ATP-PCr system provides immediate energy through rapid breakdown of stored phosphocreatine, enabling explosive acceleration from starting blocks without oxygen requirement.

Seconds 3-15:

  • ATP-PCr system remains dominant but begins depleting, with the runner achieving peak velocity as this system provides the highest rate of ATP production for maximum power output.

Seconds 15-30:

  • Glycolytic system becomes predominant as ATP-PCr stores deplete, breaking down muscle glycogen to produce ATP anaerobically, resulting in rapid lactic acid formation.

Seconds 30-45:

  • Continued dominance of glycolytic system with increasing aerobic contribution as oxygen becomes more available, though anaerobic glycolysis still provides majority of energy.

Final 15 seconds:

  • All three systems operate simultaneously with glycolytic system still dominant, but accumulating lactic acid begins interfering with muscle contraction, causing performance decline.

System integration:

  • The transition between systems is gradual rather than distinct, with optimal 400 metre performance requiring efficient switching between energy pathways and the ability to tolerate high lactate levels.

Recovery phase:

  • Post-race recovery involves replenishing ATP-PCr stores (50% within 30 seconds), removing accumulated lactate through aerobic metabolism, and restoring muscle pH levels.

HMS, BM EQ-Bank 144 MC

Which row correctly identifies the fuel source and duration of the ATP-PCr energy system?

\begin{align*}
\begin{array}{l}
\rule{0pt}{2.5ex} \ \rule[-1ex]{0pt}{0pt}& \\
\rule{0pt}{2.5ex}\textbf{A.}\rule[-1ex]{0pt}{0pt}\\
\rule{0pt}{2.5ex}\textbf{B.}\rule[-1ex]{0pt}{0pt}\\
\rule{0pt}{2.5ex}\textbf{C.}\rule[-1ex]{0pt}{0pt}\\
\rule{0pt}{2.5ex}\textbf{D.}\rule[-1ex]{0pt}{0pt}\\
\end{array}
\begin{array}{|l|l|}
\hline
\rule{0pt}{2.5ex}\textbf{Fuel Source}\rule[-1ex]{0pt}{0pt}& \textbf{Duration} \\
\hline
\rule{0pt}{2.5ex}\text{Glucose}\rule[-1ex]{0pt}{0pt}&\text{30 - 60 seconds}\\
\hline
\rule{0pt}{2.5ex}\text{Creatine Phosphate}\rule[-1ex]{0pt}{0pt}& \text{0 - 10 seconds}\\
\hline
\rule{0pt}{2.5ex}\text{Fatty Acids}\rule[-1ex]{0pt}{0pt}& \text{2+ minutes} \\
\hline
\rule{0pt}{2.5ex}\text{Creatine Phosphate}\rule[-1ex]{0pt}{0pt}& \text{30 - 60 seconds} \\
\hline
\end{array}
\end{align*}

Show Answers Only

\(B\)

Show Worked Solution
  • B is correct: CP is the fuel source and system operates 0 – 10 seconds

Other Options:

  • A is incorrect: Glucose is fuel for glycolytic system
  • C is incorrect: Fatty acids fuel aerobic system
  • D is incorrect: Duration is wrong for ATP-PCr system

HMS, BM EQ-Bank 142 MC

A sprinter runs 100 metres in 10.2 seconds. Which energy system would be the predominant source of ATP during this performance?

  1. ATP-PCr
  2. Glycolytic (Lactic Acid)
  3. Aerobic
  4. Both ATP-PCr and Aerobic
Show Answers Only

\(A\)

Show Worked Solution
  • A is correct: The ATP-PCr system is dominant for high-intensity activities lasting 0-10 seconds

Other Options:

  • B is incorrect: The Lactic Acid system dominates from 10-60 seconds
  • C is incorrect: The Aerobic system is for longer duration activities over 2 minutes
  • D is incorrect: While there is some overlap, ATP-PCr clearly dominates this short duration