[eli5] Humans and most animals breathe in O2(dioxide) and breathe out CO2(carbon dioxide) , where does the carbon come from?
In: Biology
It comes from the sugars, fats, and proteins in your body that you are using for energy. They are all chemicals made of carbon, oxygen, and hydrogen. Combining them with oxygen in your blood gives off energy your body can use, and leaves behind carbon dioxide and water. There are many chemical reactions involved, but at its basic level it’s pretty similar to fire (which also burns carbon and gives off CO2 and water).
That is also where the weight is going when you “lose weight.” You are breathing it out. And for that reason, how hard you are breathing is a good way to determine how fast you are burning calories, for example when comparing different exercises.
Latest Answers