How to breathe while running: 2:2 and 3:2 rhythms

Your body already syncs steps and breath

In 1983, biologists Dennis Bramble and David Carrier reported in Science that running mammals synchronize their steps with their breathing. Four-legged animals usually take one stride per breath. Humans use several ratios, and the favored one appears to be two strides per breath.

Thirty years later, Daley, Bramble and Carrier measured 14 adults on a treadmill, each at a self-chosen speed. Eleven showed stretches of coupling between steps and breath, and the most common ratio was again two strides per breath. A stride is two steps, so that's four steps per breath. It's a small study, but it suggests that counted rhythms put a name on something the body already leans toward.

The 2:2 rhythm: two steps in, two steps out

This one comes from Jack Daniels, the coach and exercise physiologist. He reports that more than 80% of the elite runners he has observed use a 2-2 rhythm most of the time, especially when the effort is demanding. By his math, at 180 steps a minute that's 45 breaths a minute.

Daniels describes the neighbors too. On easy runs, 3-3 is common. Late in a race or a hard session, many runners shift to 2-1 or 1-2. And he suggests using your breathing as a gauge: if you can't hold the rhythm you usually run with, you're going faster than is good for you that day.

On this site you can rehearse it with the 2:2 running rhythm: 0.7 seconds in through the nose and 0.7 out through the mouth, for 2 minutes.

The 3:2 rhythm: three steps in, two steps out

Coach and marathoner Budd Coates popularized this one under the name rhythmic breathing. Because the count adds up to five, the exhale starts on your left foot one time and your right foot the next. Coates uses it for easy and moderate running and switches to 2:1 for hills and hard efforts.

His reasoning is that impact is greatest when your foot lands just as an exhale begins, and that an odd count spreads that moment across both sides of the body. That's a hypothesis. We found no study comparing injuries between runners who use even and odd counts, so it isn't established that 3:2 prevents them.

To rehearse it, there's the 3:2 running rhythm: 1.1 seconds in and 0.7 out, also for 2 minutes.

Nose or mouth?

It depends on the effort. A 2022 review of breathing strategies for running, by Harbour and colleagues, notes that people usually switch to mouth breathing once they need to move about 40 liters of air a minute. It also cites a study in which, after a familiarization period, participants kept breathing through the nose up to about 85% of their maximal oxygen uptake.

In practice: at an easy pace you can try your nose, and when the effort climbs your mouth helps. Coates teaches breathing through nose and mouth at the same time.

Side stitches

They're very common. A 2015 review by Morton and Callister estimates that about 70% of runners felt one in the past year, and that in any given race about one in five participants gets one. The cause isn't settled. The explanation that fits best, according to the authors, is irritation of the membrane that lines the inside of the abdomen.

There's little firm ground on relief. In a survey of about 600 people, roughly 40% said deep breathing helped. Daniels says shifting to a slower, deeper rhythm sometimes gets rid of one. Some experts recommend exhaling on alternate footstrikes, as in 3:2, but the 2022 review presents that only as a possibility. Morton and Callister conclude that the most effective move is still to stop. For prevention, they suggest avoiding large amounts of food and drink in the two hours beforehand.

How to rehearse before you go

• In a chair, with the guide. Two minutes of 2:2 or 3:2, tapping the steps with your fingers on your thighs. Keep the breaths small: at rest you don't need a runner's air.
• Walking, without the guide. Count your real steps. The guide's seconds assume about 170 steps a minute, a figure this site chose. Out on the road, your feet are in charge.
• On an easy jog. Try the count for a minute or two, then let your breathing run itself. You don't need to hold it for the whole run.
• When you finish. Walk and use Catching your breath: 3 seconds in through the nose and 6 out through pursed lips, for 2 minutes.

What isn't known, and when to stop

No study shows that 2:2 beats 3:2, or the other way around. The 2022 review says there's limited evidence on learning these rhythms deliberately and that its synthesis mixes experimental data with theory. Use them as a way to get organized. If you have to force your air to keep the count, drop the count.

Chest pain, shortness of breath that doesn't ease when you slow down, dizziness or wheezing are reasons to stop and get care. If you have asthma or a heart or lung condition, check with your care provider before changing how you train.