How to breathe while running, like your cadence or running form, can be intuitive or overthought. Many runners just breathe while they run. Others seek marginal (if any) gains through specific approaches that may or may not work. This article addresses both the physiology of breathing during exercise and practical tips for how to breathe while running.
The Physiology of How to Breathe While Running
To understand how to breathe while running, you first need to understand the most simplified physiology of respiration. Breathing brings in oxygen; your body uses oxygen to produce energy. There are three basic steps in the respiratory process:
- Pulmonary ventilation: the oxygen you breathe in goes into the capillaries in the lungs; the capillaries release carbon dioxide back into the lungs
- Gas transport: oxygen from the lungs is carried and distributed to tissues in the body, including working muscles during exercise
- Tissue respiration: gas such as oxygen is exchanged between blood and muscles (along with other cells)
Lung ventilation rate is influenced by both breathing rate (frequency of breaths) and tidal volume (depth of breathing). Both tidal volume and breathing rate increase during running. At rest, your breathing rate is approximately 10 breaths per minute; during very hard running, your breathing rate may reach 30-35 breaths per minute. Tidal volume increases even more, to allow more air to flow into the alveoli in the lungs. Tidal volume is approximately 500 mL at rest, but can increase to as high as five times that during maximal effort running.
However, you do not need to consciously think about these processes while running. Neural input from both the brain and muscles regulates your breathing during exercise.
As described in a 2022 review in Frontiers in Physiology, your central nervous system (brain and spine), peripheral nervous system (everything else), emotions, cognitive attention, environmental conditions, and other factors all affect your breathing pattern while running.
You are not actively controlling the activity in your lungs; your body does that automatically in response to exercise. As presently understood, the motor and premotor centers in your brain (the “command center”) and muscle afferents (neural receptors in the muscles that send signal to the brain) control breathing. As exercise intensity increases, the brain and peripheral nervous system communicate and adjust breathing rates.
What Muscles Do You Use to Breathe While Running?
The inspiratory muscles can fatigue during prolonged efforts. The scalene and sternocleidomastoid lift the ribs so that the lungs can expand. When you exhale when running, these two muscles passively recoil, while the abdominal muscles raise intra-abdominal pressure to bring the ribs down and in.
You use these muscles so much to breathe while running that prolonged intense efforts (such as racing a marathon) can result in respiratory muscle fatigue. As outlined in this 2019 study in Sports Medicine, respiratory muscle fatigue can range from 15-25%, and pulmonary function can even decline by up to 10% following marathons or ultra-marathons.
You do not need to do any special training to strengthen these muscles. Running itself – especially long runs – strengthens your respiratory muscles over time. However, this reason is why it is important to be properly trained for long-distance races.
Can Breathing Technique Prevent Side Stitches?
Many runners are familiar with side stitches – those nasty abdominal cramps in the side that affect up to 1 in 5 runners at some point. If you suffer from side stitches, you may have wondered if how you breathe while running causes them.
The exact etiology of side stitches is still unknown. Theories range from insufficient blood flow to the diaphragm, inadequate digestion, irritation of the parietal peritoneum, or other reasons. How you breathe while running may or may not cause side stitches – we simply don’t know the exact mechanisms yet.
However, breathing may relieve side stitches when they occur. According to a 2015 study in Sports Medicine, approximately 40% of side stitch sufferers experienced relief when they did deep breathing after the stitch occurred.
Should Runners Practice Nasal Breathing?
You may hear some people preach the virtues of nasal breathing. While at rest, nasal breathing may be more beneficial than mouth breathing. However, oxygen consumption rates change with exercise. How to breathe while running will differ from how to breathe at rest.
Nasal breathing may offer some benefits for trained runners at low intensities (easy running). Nasal breathing may offer some small improvements for performance. A 2018 study found small improvements in economy with nasal breathing on runs at <85% of VO2max.
However, the benefits of nasal breathing on easy runs do not have as profound an effect as other drivers of running economy (increased mileage, strength training, carbon fiber shoes, etc.). If you want to try nasal breathing on easy runs, you certainly can! But if it doesn’t appeal to you or feel right for you, it is not something you need to worry about.
So far, no evidence is convincing that nasal breathing is the best way to breathe while running at harder than an easy run intensity. A 2017 study in the International Journal of Exercise Science found that heart rate increased more with nasal breathing during high-intensity exercise compared to mouth breathing. The higher heart rate may have been due to either higher cardiovascular stress and/or inspiratory muscle stress. Either way, nasal breathing did not improve performance at high intensities, so the researchers recommended whatever breathing pattern came naturally.
The shift from nasal breathing to mouth breathing often occurs naturally. When ventilation rates increase past 35-40 liters per minute, breathing shifts to the mouth to allow greater airflow to keep up with these oxygen demands.
For a majority of runners, a combination of nasal and mouth breathing delivers the most amount of oxygen. You likely intuitively do this on runs. Mouth breathing is commonly utilized as intensity increases. Nasal breathing simply cannot bring in enough oxygen volume for the demands of moderate to hard running. On easy runs, it is an individual preference – just know that nasal breathing is not superior to mouth breathing.
How Can I Make Breathing Easier While Running?
Does breathing feel more difficult than it should while you run? If so, there are a few potential cause.
Slow down a majority of your runs: If breathing feels difficult for you on a majority of your runs (and you have been running for more than six months), you may need to slow down. A majority (80-85%) of your runs should be at an effort that lets you carry on a conversation. Easy running allows you to train more with less fatigue and it improves your aerobic capacity. If you struggle to run easy enough or are a new runner, consider using run-walk intervals to help control your breathing rate.
Wear a sports bra that fits: Too tight of a sports bra can constrict the expansion of your diaphragm, which may make breathing feel harder. Ensure your sports bra fits properly, including at the band around the ribs.
Maintain upright posture: Try this at rest: take a deep breath in while sitting upright, then a deep breath in while slouched forward. Notice a difference? Excessive slouching compresses your lungs and diaphragm. Both organs can full expand when you maintain an upright posture. Think of running tall, with shoulders down.
Can Breathing Be Used to Gauge Exercise Intensity?
The harder you work, the more your breathing rate increases. Oxygen is used along with fats and carbohydrates to produce energy when running. When you run easy, your breathing is pretty light – light enough that you can carry on a conversation. The faster and faster you run, the more energy you need – and so the more oxygen your muscles need to produce energy.
You will notice increases in your breathing rate as intensity increases. Breathing feels pretty comfortable at most easy to moderate intensities. Your body is able to maintain a balance of oxygen uptake and carbon dioxide expulsion.
Once you start working harder, breathing increases non-linearly and more rapidly than before. It becomes a bit harder around your lactate threshold (one-hour race effort), fairly more difficult at critical velocity (30 min race effort), and a lot more difficult at your VO2max pace (7-10 min race effort). VO2max is your maximum oxygen consumption – once you hit this point, you probably want to drop your hands on your knees and catch your breath.
The Respiratory Exchange Ratio (RER) demonstrates this relationship. The RER is the ratio of carbon dioxide production to oxygen uptake. The more oxygen you consume, the higher your RER. A high RER of 1.0 indicates that you are using more carbohydrates than fat for energy production. As we know from basic bioenergetics of running, the harder you run, the higher ratio of carbohydrates you use for energy production. You consume more oxygen and burn more carbohydrates to run harder – which means you are breathing harder.
In short: your breathing rate corresponds with exercise intensity. You can use it to gauge exercise intensity, no matter the weather, terrain, or other conditions.
Breathing Rates for Different Types of Runs
As discussed above, your breathing rate increases as you run harder. Along with the rate of perceived exertion and heart rate, your breathing rate provides a physiological tool to gauge exercise intensity.
- Easy runs: breathing is elevated slightly, but controlled enough that you can converse with a training partner. Often, this is a pattern of 3-4 counts inhale/3-4 counts exhale.
- Threshold runs: breathing is slightly labored, around a pattern of 2-3 counts inhale/2 counts exhale. Your breathing is elevated enough that you can only speak short phrases before needing to breathe.
- High-intensity interval runs: breathing is labored so that you can only speak a couple of words before breathing again. Your breathing pattern is likely 1-2 counts in/1 count out.
Housh, Housh, & deVries. (2016). Applied exercise and sport physiology with labs. 4th ed. Holcomb Hathway.