Explain how the three energy systems provide ATP during a 1500 metre running race. (6 marks)
--- 18 WORK AREA LINES (style=lined) ---
Show Answers Only
Sample Answer
- The ATP-PCr system provides immediate energy for the explosive start.
- Stored phosphocreatine rapidly regenerates ATP without oxygen, enabling acceleration to race pace and tactical positioning for 10-15 seconds.
- As PCr depletes, the glycolytic system becomes dominant from around 15 seconds onwards.
- This occurs because glucose breaks down anaerobically, producing ATP quickly for sustained speed.
- Lactic acid accumulates during this phase, causing progressive fatigue and burning sensations after 30-60 seconds.
- Consequently, runners must regulate intensity to manage lactate build-up and maintain pace.
- The aerobic system provides the majority of ATP throughout the race due to oxygen enabling complete glucose breakdown.
- This sustained energy production allows runners to maintain race pace during middle segments.
- Therefore, aerobic capacity determines sustainable race pace for most of the event.
- All systems work simultaneously with varying contributions depending on intensity changes.
- Tactical moves and pace variations result in shifts between system dominance throughout.
- The final sprint relies on recovered PCr and increased glycolytic activity despite fatigue.
- Thus, successful 1500m performance requires managing all three energy systems through tactical pacing.
Show Worked Solution
Sample Answer
- The ATP-PCr system provides immediate energy for the explosive start.
- Stored phosphocreatine rapidly regenerates ATP without oxygen, enabling acceleration to race pace and tactical positioning for 10-15 seconds.
- As PCr depletes, the glycolytic system becomes dominant from around 15 seconds onwards.
- This occurs because glucose breaks down anaerobically, producing ATP quickly for sustained speed.
- Lactic acid accumulates during this phase, causing progressive fatigue and burning sensations after 30-60 seconds.
- Consequently, runners must regulate intensity to manage lactate build-up and maintain pace.
- The aerobic system provides the majority of ATP throughout the race due to oxygen enabling complete glucose breakdown.
- This sustained energy production allows runners to maintain race pace during middle segments.
- Therefore, aerobic capacity determines sustainable race pace for most of the event.
- All systems work simultaneously with varying contributions depending on intensity changes.
- Tactical moves and pace variations result in shifts between system dominance throughout.
- The final sprint relies on recovered PCr and increased glycolytic activity despite fatigue.
- Thus, successful 1500m performance requires managing all three energy systems through tactical pacing.