What is the best way to breathe while running long-distance? One can breathe in through the nose only, the mouth only, or both nose and mouth. The same applies to breathing out. Are there studies comparing the advantages and disadvantages of the various methods?
I run only as fast as I can breath through my nose. Our respiratory system is designed such that for any level of aerobic activity in which we regularly participate we can obtain sufficient oxygen by breathing through our nose. I don't know what kind of pace you want to run at, or how long you mean by long distance, so there's considerable room for interpretation here, but in the long run most people are better off breathing through their nose as much as possible.
- Our sinuses and nasal passages are designed to clean, humidify, and heat or cool the air we breath to provide optimal oxygen uptake in the lungs. Our mouths provide no such service. Dust and particulates flow quite freely through the mouth and throat. (I'm not saying our noses can filter out everything, but any filtering is better than none).
- Running at a pace that allows for breathing through the nose will encourage you to slow down enough to build your aerobic base, enhancing your bodies ability to burn fat and use the oxygen you breath. As time progresses, this pace will increase, and eventually you will be able to run as fast as you previously were while breathing through your mouth.
- Breathing through your nose helps your body stay relaxed, and helps keep your heart rate lower for a given rate of exercise. Translated to running, this means you don't feel like you're working as hard as you do when you breath through your mouth.
- Breathing only through your nose will force you to run slower until your body adapts. There is a major emphasis on speed training, intervals, etc in the running community, and most people are unable to function without gulping down huge mouthfuls of air. When you take a way that air volume, you have to slow down for a while while your body builds its natural aerobic efficiency back up. Many people have a hard time being patient during this retraining period.
- It feels a little stressful if your nose starts feeling like its getting clogged, or runny. This is your body telling you to slow down a little bit. Again, many people don't want to slow down.
Anecdotally, I've seen great benefits from breathing only through my nose as often as possible, not just when running. Living in a dry climate, I often ended up with a semi-permanent sore throat when running or cycling a lot. Switching to nose-only breathing initially slowed me down significantly, but in a couple of months I was right back where I started, but feeling much more relaxed when I run.
Disclosure: My fitness has degraded significantly in the last 6 months, as I quit my job to go back to being a full-time student to finish my degree, then moved to a different state and started another job. Before that, I was able to run several miles (~10) at a comfortable 9:30 minute per mile pace while only breathing through my nose.
There is a summary of some of the research done by Dr. Lieberman at Harvard here.
You should always breathe in through both your nose and mouth and out through your mouth. you cannot get enough of the needed oxygen only using your nose or mouth by itself.
You should allow air to enter through both your mouth and nose when you're running. Your muscles need oxygen to keep moving and your nose simply can't deliver enough. Make sure you're breathing more from your diaphragm, or belly, not from your chest -- that's too shallow. Deep belly breathing allows you to take in more air, which can also help prevent side stitches.
You should exhale through your mouth and try to focus on exhaling fully, which will remove more carbon dioxide and also help you inhale more deeply.
I've never found it possible to consciously breathe in through my mouth and nose at the same time. I recommend just opening your mouth and breathing. The deeper down you take the breath the better off you'll be but I wouldn't be artificial about it.
This is one of the things that will naturally develop for you as you train.
Lastly, I would note that sometimes the stitch is caused by a different pattern of foot strides to breaths - e.g. because you're running up or down hill. Often, the stitch can be fixed by consciously changing your striding pattern to something different.
I agree that "One can breathe in through the nose only" and if it works for you then why stop. I tried nose breathing when doing weights years ago after reading an article on its benefits but gave up because I found it near impossible. Recently over the last month I tried it again incorporating it into my 1 hour bike rides which includes riding up steep hills I am amazed at the results. Initially I took it easy but I have now reached the point where I am as fast as I was when I was breathing through my mouth averaging around 25km/h. I have noticed that by concentrating on a regular balanced deep breathing pattern of inhaling and exhaling through the nose climbing hills seems much more manageable.
I agree with @alesplin. IMO, breathing is directly related to one's stamina. If you have good stamina, then you can run or workout more which is ultimately the result of proper oxygen supply to your blood and muscles. Everything in the start is slow. If you want an explosion of oxygen to increase your running distance/pace, only possibility is to start slow.
You can practice deep breathing with your nose while breathing in and with your mouth while breathing out, when running. Initially you will only be focusing on breathing properly, but that's ok because when it's going to be unnoticeable, you never know. But the rewards will be plenty. You will have increased stamina and your breathing will be coordinated with your steps. By practicing deep breathing, you will have increased supply of oxygen which will curb the lactic acid formation in your body muscles. As the quantity of lactic acid in the muscles decrease, you will tire less. But this will be a gradual process. And it will be fruitful. I have been practicing it since one year and the results are very rewarding. I have scaled from 500m to 6kms non stop just by practicing this.
I focus primarily on breathing out, making sure my lungs are cleared of air as much as possible. With the effort on breathing out, the lungs just fill up naturally due to the pressure difference (same with playing a wind instrument incidentally).