On an average, an adult human being at rest breathes 15–18 times per minute. The breathing rate, however, may differ under different conditions. Arrange the following activities given in the box in order of increasing breathing rates and give reason for your answer.
sleeping, cycling, brisk walk, watching T.V.
sleeping < watching TV < brisk walk < cycling
The number of times a person breathes in a minute is known as the breathing rate. Normally it is 15 to 18 times per minute but can change depending upon the type of work a person is doing. During heavy exercise the breathing rate can increase upto 25 times per minute. This can be noticed while running that we take not only fast breaths but deep breaths also.
During sleeping the human body is completely at rest and therefore the oxygen required by the body is minimum.
While watching TV no extra work is done but atleast the body is awake and therefore the requirement of oxygen by the body is slightly more than while the person is sleeping.
While brisk walk the amount of oxygen needed is more and hence the breathing rate would definitely be more.
While cycling, the breathing rate would be maximum. It can go up to 25 times per minute.