A Jamaican athlete's resting heart rate is 60 beats per minute. During a 100-metre sprint at the National Stadium, her heart rate increases to 180 beats per minute. Which statement best explains this increase?

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Question

A Jamaican athlete's resting heart rate is 60 beats per minute. During a 100-metre sprint at the National Stadium, her heart rate increases to 180 beats per minute. Which statement best explains this increase?

Accepted Answer

Her heart needs to pump more blood to deliver oxygen to working muscles — Award 1 mark for explaining that increased heart rate raises cardiac output to meet the oxygen demands of exercising muscles. A is incorrect — muscles need more oxygen during exercise. C is incorrect — blood pressure typically increases during exercise. D is incorrect — this would not cause increased heart rate as a normal response.

Answer

Her muscles need less oxygen during exercise

Answer

Her blood pressure decreases during exercise

Answer

Her heart needs to pump more blood to deliver oxygen to working muscles

Answer

Her lungs are not working efficiently

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