BREATHING! The way you move air into and out of your body is about the most important thing that you can improve, and likely change to make your runs more meaningful and less taxing on your body.
How you ask?
I’m not going to tell you that, because everyone breathes differently. I have found this information to be very helpful with my own runs. When you run your natural reaction is to do so rhythmically, breathe in for two steps, breathe out for two steps. This is great, practical, gets it done and works great.
What I’m telling you is that if you vary that once in a while and breathe in as deep as you can, then blow out all the air that you possibly can you will benefit from the air you breathe more so than if you do the two in, two out method. When you do the deep breathing now and then you are rushing oxygen into your body that automatically fuels the blood to your muscles making them work more efficiently, and therefore not tiring you as quickly.
When you stick to the two in, two out method you are only using the top of your lung capacity. Think of a bucket of water. If you only dump the top portion out and then refill it, how much water will you move? Not much. If you dump all of it, then completely refill it, we’ll you catch my drift.
Lastly, if you are running and its just all you can do to breathe, STOP! Slow your heart rate down and start again. I can’t stress how much you have got to listen to your body. When you do start back try breathing only through your nose for the remainder of your run, this will only allow your body to go as fast as you have the oxygen for.