A marathon runner is running a race. During the race the marathon runners heart rate and breathing increases. Which of the following explains why the marathon runners' body is responding in this way?

Warmer temperatures increase your heart rate. In addition to pumping more blood to the muscles, your heart also transports more blood to the skin in order to cool it. Increased demand causes your heart to beat faster -- anywhere from 20 to 40 beats per minute higher than normal.

Explanation:

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rain is the best answer

answer:   option a) glucagon was secreted by his pancreas before he ate the cookies because blood glucose was low. insulin was secreted after he ate the cookies because his blood glucose was high.

explanation: