Ready, Set, Go! How the Heart and Lungs Respond to Exercise

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