Most runners don’t think about the way they are breathing unless it is a struggle. In fact, that is probably true for runners and non-runners alike. Breathing is just something our body and brains do for us. So, unless you are swimming, have a cold, or are asthmatic you haven’t thought about the way that you breathe when you run.
The way you breathe as you run can help or hurt you. Budd Coats and Claire Kowalchik’s book, “Running on Air,” explains the ins and outs of belly breathing and rhythmic breathing including the scientific research behind it.
Rhythmic breathing is a way to reduce your injury risk (I am all about reducing injury and staying running) and increase your efficiency and pace while running. As shown in, “Running on Air,” your core muscles are at their weakest when you exhale. If you continuously land on your left or right foot when you exhale, you are likely to end up with injuries on that side of your body.
If, however, you develop a 3-2 and 2-1 rhythm to your breathing (inhale for three steps, left right left, exhale for two steps, right left) you balance the impact to both your left and right sides. This reduces the risk of injury. Rhythmic breathing can also help with exercise-induced asthma and with side stitches while running.
Easy runs and long runs should be in the 3-2 pattern. The 2-1 pattern is used during hill climbs and when you are sprinting.
Initially you have to make a conscious decision to count your breathing, noticing what is going on when your foot touches the ground. After a few weeks, it becomes easier and more natural and you only have to check in with your body every so often to make sure you are maintaining the pattern.
Before I started using this breathing pattern, I would constantly pull my right hip flexor and my right IT Band would tighten up. I read a short article about rhythmic breathing in Runners World and then bought the book. Since then, I’ve used the rhythmic breathing and I haven’t had the same problems on the right side or the left for that matter.
You’ve got nothing to lose by trying it.
ultrarunningmom 
Interesting. I will give it a try. I started doing deep breathing exercises before my runs, and it has helped tremendously
Very timely article! I normally have a very easy breathing pattern in my runs, but have been developing side stitches lately. I’m training for triathlon right now, so I’m wondering if my cardio system just needs to catch up? Lots to think about!! Great to meet you today 🙂
Give it a try. I hope it helps.