Fatigue can actually be considered a kind of poisoning! When a muscle in our body works, it produces lactic acid. If we remove the lactic acid from a tired muscle, it is able to start working again at once! There are other substances the body produces in the course of muscular activity. These are known as “(fatigue toxins”. The blood carries these through the body, so that the muscle itself, the entire body, and especially the brain feels tired.
Scientists have conducted interesting experiments on fatigue. If a dog is made to work until it is exhausted and falls asleep, and its blood is then transfused into another dog, the second dog will instantly become “tired” and fall asleep! If the blood of a wide-awake dog is transfused into a tired, sleeping dog, the latter will wake up at once, no longer tired!
But fatigue is not just a chemical process, it is also a biological pro- cess. We cannot just “remove” fatigue, we must allow the cells of the body to rest. Damages must be repaired, nerve cells of the brain must be “recharged”, and the joints of the body must replace used up lubricants.
Sleep will always be necessary as a way of restoring our body’s energy after fatigue. Very often, the best way to make a tired body part feel fresh again is to make other parts of the body active! We can actually rest by means of activity. Activity increases respiration. The blood circulates faster, the glands are more active, and the waste products are eliminated from the tired part of the body. But, if you are totally exhausted, the best thing to do is sleep!
Why Do You Feel So Tired?
There are many possible causes for feeling chronically tired. It’s important to rule out medical conditions first, as fatigue often accompanies illness.