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This Psychology Today blog post is phase four of a nine-part series called "The Vagus Nerve Survival Guide." The nine vagal maneuvers featured in each of these blog posts are designed to help you stimulate your —which can reduce stress, , , and inflammation by activating the "relaxation response" of your parasympathetic .

New research from the University of Arizona reports that just 20 minutes of “narrative expressive writing” over a three day period can trigger a physiological chain reaction that was found to improve heart rate variability (HRV), which is the measurement of variations within beat-to-beat intervals and indicates cardiovascular health.

Although this study doesn’t look at directly, previous research has shown that increased HRV is linked to a robust parasympathetic nervous response and stronger vagal tone, which counterbalance the “fight-or-flight” stress responses of the sympathetic nervous system.

The UA paper, “The Impact of Narrative Expressive Writing on Heart Rate, Heart Rate Variability, and Blood Pressure Following Marital Separation,” was published May 8 in the journal Psychosomatic Medicine.

This study included 109 adults (70 women and 39 men) who had recently experienced the stress of a marital separation. Participants were randomly assigned to one of three writing exercises, which were performed for 20 minutes a day over the course of three consecutive days.

One group performed a traditional “expressive writing” (EW) task, with instructions to wear their heart on their sleeve and write freely about their "strongest and deepest emotions." Another group was instructed to perform a “narrative expressive writing” task, in which they created a "coherent and organized narrative" of their marital separation with a storyline arc with a beginning, middle, and end to their " story." The third group was given an emotionally neutral writing task.

Cardiovascular markers for stress were compared before and after the various styles of writing a journal entry. Interestingly, participants assigned to the “narrative expressive writing” group showed the greatest reduction in cardiovascular markers for stress as well as an increase in heart rate variability (HRV).

Why Would Narrative Expressive Journaling Improve HRV and Vagal Tone?

In 2016, Igor Grossmann and colleagues from the University of Waterloo published a paper, “A Heart and A Mind: Self-distancing Facilitates the Association Between Heart Rate Variability and Wise Reasoning,” which reaffirmed that vagal tone (indexed via HRV) was associated with superior and wiser reasoning. Grossmann et al. hypothesize that adopting a self-distanced (as opposed to a self-immersed) perspective (which is achieved by narrative expressive writing) is correlated with higher HRV along with the ability to overcome -promoting egocentric impulses and to reason more wisely.

In a statement, the UA paper’s lead author, Kyle Bourassa, said, "To be able to create a story in a structured way—not just re-experience your emotions but make meaning out of them—allows you to process those feelings in a more physiologically adaptive way. The explicit instructions to create a narrative may provide a scaffolding for people who are going through this tough time. This structure can help people gain an understanding of their experience that allows them to move forward, rather than simply spinning and re-experiencing the same negative emotions over and over."

Notably, a previous 2013 study, “Expressive Writing Can Impede Emotional Recovery Following Marital Separation,” led by UA principal investigator David Sbarra, who is Director of the Laboratory for Social Connectedness and Health, found that participants going through a divorce who had a tendency towards high psychological rumination (and may have difficulty self-distancing) reported significantly worse emotional outcomes when assigned to a traditional "heartfelt” expressive writing group without a narrative storyline. These findings appear to corroborate Grossmann’s theory that self-distancing is an integral part of boosting HRV by overcoming the arousal of emotionally egocentric impulses linked to high rumination.

In a statement, Dr. Sbarra said, "From this work, we can make two specific conclusions. First, relative to the two other conditions, narrative expressive writing caused the changes we observed in the cardiovascular biomarkers. This is a pretty striking result for just 60 minutes of writing over three days. Second, the effects of narrative writing on these health-relevant biomarkers is independent of adults' self-reported emotional responses about their separation. Creating narrative may be good for the heart, so to speak, but this does not mean there a corresponding improvement in psychological wellbeing."

That being said, Sbarra urges caution when interpreting these findings: "To be clear, this study points to causal changes in health-relevant cardiovascular responding, not health outcomes per se. Further research will be needed to clarify the links between these biomarkers and the long-term health outcomes of people after divorce."

Goring through a divorce is a traumatic experience that triggers universal stress responses associated with a sympathetic nervous system, lower HRV, and reduced vagal tone. The good news is that the latest research suggests that self-distancing via narrative expressive writing can trigger a healthy chain reaction and upward spiral by activating the triad of a robust parasympathetic response, better HRV, and improved vagal tone. Hopefully, these findings will inspire you to take about 20 minutes per day (for at least three days in a row) the next time you find yourself going through a experience.

Narrative expressive journaling is a readily accessible tool anyone can use during times of psychological and autonomic nervous system distress to boost your parasympathetic nervous system, engage your vagus nerve, and improve your HRV. More specifically, the latest empirical evidence from the University of Arizona prescribes narrative expressive writing as one way to reduce the physiological toll of going through a divorce.