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)

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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.

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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.