Question

When you run, your breathing becomes faster as you need more oxygen. But why does your rate of heartbeat also increase?

Answer 1

The oxygen intake is increased as constant supply of it is needed to produce energy. Other thing than lungs that consume energy while running are the muscles.
So as the lungs need constant fresh air increasing the amount of oxygen intake.
Similarly, the muscles need blood to flow through them to keep them energized. The pumping of blood if done by the heart and so there is increase in the heartbeat or the heart rate also.
 

Answer 2

Hello !!
Here's ur answer! !
The intake of oxygen is increased as it is needed constantly to produce energy to the muscles. as the lungs fresh air and oxygen constantly,the muscles need blood supply to give them energy to run. the heart pumps the blood to all parts of the body and it has to work faster and give more blood supply.so there is increase in the rate of heartbeat.
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