For a new study in Physiology & Behavior, researchers gave 34 participants an anxiety assessment and then rigged them up with electrodes to follow their respiration, muscle tension, and other indicators of relaxation (or the lack thereof). Every participant did three different trials: one where they didn’t receive breathing instructions, and two where they did, either receiving the instruction “‘During one of the following breaths: breathe in as deeply as possible” or “‘During one of the following breaths: delay your next inspiration for 2 s[econds].” The participants self-reported how much relief they felt five seconds before and after their breath, and their physiological anxiety markers were recorded at the same intervals. Spontaneous deep breaths — sighs, if you would — were also tracked.
Surprisingly, those spontaneous deep breaths didn’t bring a sense of psychological relief, but the instructed ones did. (The researchers, all from the University of Leuven in Belgium, reason that that might be the case because participants were looking to respond to the stimuli — as in breathing instructions — that they were expecting to be presented to them). Yet the biomarkers indicated that, for the people who rated high on anxiety, the spontaneous sighs brought physiological relief. And, surprising to the researchers, the breath-hold instruction decreased muscle tension for those lucky low-anxiety folks. For both high- and low-anxiety people, following the deep-breath instructions brought a sense of psychological relief. According to lead author Elke Vlemincx and her colleagues, the results fit with their prediction that sighs are “psychological and physiological resetters.”
This is a small study: 34 is not many people. Still, the results are pretty interesting; first of all, the fact that both consciously breathing and holding your breath is relief-inducing coheres with lots of traditional wisdom around breathing exercises, which have been shown to help cancer patients with anxiety and reduce asthmatics’ daily use of inhalers. Also, the most common summation of mindfulness meditation is that it’s attending to both the in- and out-breath, and that practice has been shown to reduce anxiety in clinical populations, so maybe something similar is happening here, though the researchers don’t call it mindfulness. One possible mechanism: Paying attention to and regulating your breath is an active, conscious way to communicate with the unconscious parts of yourself that your body is safe. And voilà, you relax.