The importance of regulating your stress levels cannot be understated. Not only can stress take its toll on your mental health, but it can also impact you physically, with symptoms ranging from headaches and bloating to irregular periods. And if those high stress levels persist over an extended period of time, you’ll be at risk of developing burnout. All of that’s to say that dealing with your stress on a daily, weekly and monthly basis is key if you want to look after your wellbeing. There are, of course, plenty of ways to do this. Exercise, spending time with family and friends and getting outside will all help. But if you’re short on time, then doing some controlled breathwork – specifically an exhalation-focused practise like ‘cyclic sighing’ – could be the key to feeling more relaxed and in control. The relationship between controlled breathwork and stress reductionCyclic sighing involves breathing in a 1:2 ratio, with an inhale which takes half as long as the exhale.Recent research has confirmed what experts in the field have known for years – that the long exhalations associated with these kinds of techniques calm the autonomic nervous system, reduce physiological arousal, lower stress and reduce feelings of anxiety. The study, carried out by a team at Stanford University, saw participants take part in one of four different practices – three different controlled breathwork techniques and mindfulness meditation – to see which was most effective at boosting mood and reducing stress. The breathwork techniques in question were exhale-focused cyclic sighing (made up of a 1:2 ratio in which the exhalation is twice as long as the inhalation), box breathing (made up of an inhalation, retention and exhalation pattern of equal lengths) and cyclic hyperventilation (a sequence of ‘robust’ inhalation followed by a short retention and rapid exhalation). The group of 108 participants were split into four groups and each assigned one of the three breathwork techniques or mindfulness meditation, and were asked to practise their technique for five minutes per day over 28 days. Those in the mindfulness meditation group were the only ones not instructed to regulate their breathing – instead, they were asked to focus their mental attention on the “forehead region” between their eyes.After the 28 days, the study’s authors found that, while all four groups experienced “reductions in state anxiety and negative effect” and “increases in positive effect”, it was the group who practised exhale-focused cyclic sighing who experienced the biggest reduction in physiological arousal and most significant boost to their mood. Indeed, as the study’s authors write: “We found that the cyclic sighing group had a significantly higher increase in positive affect than those in the mindfulness meditation group. The other two breathwork groups were also higher than mindfulness meditation; however, this difference was not significant. “Cyclic sighing also had a significant interaction with cumulative days on protocol compared with mindfulness meditation, suggesting that subjects benefited more from the exercise the more days they did it, an effect not observed in the other groups.” Why is ‘cyclic sighing’ such an effective way to reduce stress?There are a number of reasons why the study’s authors believe cyclic sighing was the most effective technique at reducing stress.It’s clear that breathwork – specifically exhalation-focused cyclic sighing – is an effective way to reduce stress and boost mood. But why is this? The study’s authors put forward two main theories – vagus nerve stimulation, and enhancement of ‘interoceptive processes’. The former is something you might have heard about before. The longest nerve in the human body, the vagus nerve is the main component of the parasympathetic nervous system – the side of our nervous system responsible for the ‘rest and digest’ state as opposed to the ‘fight or flight’ state triggered by the opposing sympathetic nervous system. It’s long been known that specific breathing techniques can help to module vagal function (often observed through a change in heart rate variability, or HRV), specifically those which involve extended exhalations like exhalation-focused cyclic sighing, so it makes sense that the participants who tried breathing techniques saw a reduction in their stress levels. The enhancement of ‘interoceptive processes’, however, is more about the way that breathing techniques can help us to focus on what’s going on in our bodies. By promoting interoceptive awareness, controlled breathwork can make us more aware of when we’re feeling stressed, giving us more time to act on those signs before things get out of hand. The impact which controlled breathing can have on the regulation of emotion and mood and the sense of control it provides the person practising it were also put forward as theories. While the study’s authors say they need to do more research to properly understand why exhalation-focused breathwork is so effective in reducing stress and boosting mood, it’s certainly worth giving it a go if you’re finding it hard to relax and switch off at the end of the day. By taking control of your breathing, you’ll not only be giving your vagus nerve a workout, but you’ll also be taking time to pay attention to your body and get to know it better so you can read your stress signals more easily in the future.