Author:
Muise Eleanor D.,Gordon Rachel,Ericson Woods Dawn A.
Abstract
You know when you’re racing really fast—so fast that your heart is pounding, and you can’t catch your breath? Have you ever wondered why that happens? Imagine you are racing—when you take a deep breath, you breathe in air and your lungs pull oxygen into your blood, then oxygen races to your hungry leg muscles. All that work by your muscles to make energy creates carbon dioxide waste, which travels back to the lungs, and we exhale with a sigh of relief. As you and your muscles work harder to run faster and further, your muscles require more oxygen to make more energy. Over time, with continued exercise, your heart and lungs respond by becoming more efficient at delivering oxygen and making energy. There are even ways to measure how hard your body is working during exercise, and this article will tell you how!