Explain how the intensity of exercise influences the predominant energy system used. (3 marks)
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Sample Answer
- Exercise intensity determines which energy system predominates based on ATP demand rate.
- Maximal intensity requires immediate ATP, causing ATP-PCr system dominance for 10-15 seconds, as seen in sprint starts.
- As intensity decreases, the glycolytic system engages for sustained high-intensity efforts lasting 30-90 seconds.
- Lower intensities allow oxygen-dependent aerobic metabolism, which enables sustained ATP production from fats and carbohydrates.
- Therefore, decreased intensity permits longer duration activity, as demonstrated in marathon running.
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Sample Answer
- Exercise intensity determines which energy system predominates based on ATP demand rate.
- Maximal intensity requires immediate ATP, causing ATP-PCr system dominance for 10-15 seconds, as seen in sprint starts.
- As intensity decreases, the glycolytic system engages for sustained high-intensity efforts lasting 30-90 seconds.
- Lower intensities allow oxygen-dependent aerobic metabolism, which enables sustained ATP production from fats and carbohydrates.
- Therefore, decreased intensity permits longer duration activity, as demonstrated in marathon running.