Explain how the interplay of energy systems changes during a 400-metre run. (4 marks)
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Sample Answer
- At the start, the ATP-PCr system provides immediate energy for explosive acceleration, lasting only 10-15 seconds.
- As PCr depletes, the glycolytic system becomes dominant, producing ATP quickly but creating lactic acid build-up.
- This causes burning sensations and fatigue by 200-300 metres, forcing runners to slow slightly.
- The aerobic system contributes increasingly throughout, providing baseline energy to support the anaerobic systems.
- In the final 100 metres, all three systems work together, with glycolytic dominance causing significant fatigue.
- Therefore, the 400 metre run requires careful pacing to manage the shifting energy system contributions.
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Sample Answer
- At the start, the ATP-PCr system provides immediate energy for explosive acceleration, lasting only 10-15 seconds.
- As PCr depletes, the glycolytic system becomes dominant, producing ATP quickly but creating lactic acid build-up.
- This causes burning sensations and fatigue by 200-300 metres, forcing runners to slow slightly.
- The aerobic system contributes increasingly throughout, providing baseline energy to support the anaerobic systems.
- In the final 100 metres, all three systems work together, with glycolytic dominance causing significant fatigue.
- Therefore, the 400 metre run requires careful pacing to manage the shifting energy system contributions.