Explain the relationship between ventilation rate and lactate levels during and after high-intensity exercise. (5 marks)
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Sample Answer
- During high-intensity exercise, ventilation rate increases significantly to supply oxygen to working muscles and remove carbon dioxide.
- As exercise intensity increases beyond the aerobic threshold, lactate begins to accumulate in the bloodstream due to insufficient oxygen for complete aerobic metabolism.
- The increasing lactate levels cause blood pH to decrease (become more acidic), which triggers the respiratory system to respond.
- This response from the respiratory control centre increases ventilation rate to help buffer the acidity by expelling more carbon dioxide.
- After exercise ceases, ventilation rate remains elevated while lactate is cleared from the bloodstream, gradually returning to normal as lactate levels decrease during recovery.
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Sample Answer
- During high-intensity exercise, ventilation rate increases significantly to supply oxygen to working muscles and remove carbon dioxide.
- As exercise intensity increases beyond the aerobic threshold, lactate begins to accumulate in the bloodstream due to insufficient oxygen for complete aerobic metabolism.
- The increasing lactate levels cause blood pH to decrease (become more acidic), which triggers the respiratory system to respond.
- This response from the respiratory control centre increases ventilation rate to help buffer the acidity by expelling more carbon dioxide.
- After exercise ceases, ventilation rate remains elevated while lactate is cleared from the bloodstream, gradually returning to normal as lactate levels decrease during recovery.