I have always been vaguely self-conscious about my breathing in relation to its effects on my somewhat irregular heartbeat. It was therefore nice to find out that breathing patterns do have a real effect on heart rate and I wasn’t just imagining things. In fact, two of the breathing techniques we have learnt in class are known to stimulate the parasympathetic pathway, which reduces heart rate.
The first is the slow breathing and extended exhalation that feature as part of Nadi Shodhana. This is the one where we are supposed to gently exhale for about twice as long as the next inhale. Theoretically, the parasympathetic pathway is activated as part of exhalation while the sympathetic pathway is activated as part of inhalation. Regular practice of Nadi Shodhana should therefore have a calming effect on heart rate.
The second is Ujjayi breathing that we should be practicing while performing our asanas. Ujjayi breathing is interesting because the inhalation and exhalation is at the same rate, but the air travels differently due to the partial closure of the glottis. The resulting air turbulence is thought to stimulate branches of the vagus nerve, activating the parasympathetic pathway.
Now, I run fairly regularly and naturally breathe in a 3:3 pattern i.e. 3 footstrikes per inhale and 3 footstrikes per exhale. According to influential work by Budd Coates and Claire Kowalchik (see http://www.runnersworld.com/running-tips/running-on-air-breathing-technique), this type of “even-count” breathing pattern causes problems. Because you are always exhaling on the same foot, this results in a greater impact and thus injury to the same side of the body.
Coates and Kowalchik recommend an “odd-count” pattern (e.g. 3:2 or 2:1) such that you alternate the exhaling foot and even out the stress. I have tried using the 3:2 pattern several times before and was always borderline stressed, even when going at a slower-than-usual pace. I am now wondering if this is partly due to the suppression of the parasympathetic system with the shortened exhalation.
An alternative could be to use a 2:3 pattern instead. But Coates and Kowalchik recommend a longer inhalation than exhalation because the body is more stable during inhalation. I quote: “Your diaphragm and other breathing muscles contract during inhalation, which brings stability to your core”. I suspect (though I haven’t read the book) that this is related to the increase in intra-abdominal pressure as the diaphragm contracts during inhalation, acting as a passive stabilizer of the core. This is the same theory behind the Valsalva maneuver used in power lifting, which is NOT recommended for beginners because it momentarily increases blood pressure. This is why we are generally told to exhale (not hold our breath) during exertion in most gym workouts. Better to work on strengthening those core muscles than risk cardiac arrest.
Now the last option would be to go back to an even-count pattern but alternating the exhaling foot every so often. Better yet, how about we throw in Ujjayi breathing? I haven’t tried this but it seems (from Google) that some runners have found this to be beneficial. With the Star Wars Run coming up this weekend, the timing couldn’t be more perfect. I just need to find myself a Darth Vader costume ;>
~ allyson (200hr Apr weekend)