Influence of a 30-Day Slow-Paced Breathing Intervention Compared to Social Media Use on Subjective Sleep Quality and Cardiac Vagal Activity

Citation

Laborde S, Hosang T, Mosley E, Dosseville F. Influence of a 30-Day Slow-Paced Breathing Intervention Compared to Social Media Use on Subjective Sleep Quality and Cardiac Vagal Activity. J Clin Med. 2019 Feb 6;8(2):193. doi: 10.3390/jcm8020193. PMID: 30736268; PMCID: PMC6406675.

4 FUNDAMENTALS

 

1. Essential Background Material

 

This study examined how 30 days of slow breathing before sleep affected subjective sleep quality and nighttime and morning vagal tone.

 

Good sleep is the foundation of health.  And although I’m not a big fan of meticulously monitoring our sleep or getting bent out of shape over a few bad nights, I am a fan of doing everything we can to set ourselves up for good sleep. 

 

And slow breathing before bed might be one such tool for this.  Overarousal and overstimulation are two key drivers of poor sleep.  Slow breathing counters these by activating the parasympathetic (rest-and-digest) nervous system. 

 

Although the connection is straightforward, little research has been done on this topic, and only a few studies exist looking at the impact of nighttime slow breathing on sleep.

 

This study aimed to fill this gap by analyzing how slow breathing before bed impacted subjective sleep quality and, subsequently, how those changes were related to nighttime and morning vagal tone.

 

 

2. What Did this Research Do?

 

Sixty-four people (31 female; 33 male) between 18-29 years old took part in the study. 

 

Before sleep, subjects in the breathing group performed 15 minutes of slow breathing at 6 breaths per minute using a 4.5-second inhale and 5.5-second exhale.  They used a nasal inhale and pursed lips exhale.  They did this for 30 days and could not miss more than 3 sessions to be included in the study.

 

A control group looked at social media for 15 minutes before going to bed.  I’m not going to consider this group—the focus here is on slow breathing itself, not on how slow breathing compares to social media. 

 

To measure sleep quality, they used the Pittsburgh Sleep Quality Index (PSQI), which consists of 18 questions to assess different aspects of sleep. 

 

To measure vagal tone, they used high-frequency HRV (HF-HRV).  Recall from a previous Laborde et al. paper that RMSSD is typically the best marker of vagal tone.  However, HF-HRV works here because the breathing rate was greater than 9 breaths/min when the measurements were taken (overnight and morning).

 

Measurements were taken one night at the start of the experiment (pre-test) and one night at the end of the experiment (post-test).  Nighttime vagal tone was assessed during sleep, whereas morning vagal tone was measured first thing upon waking.  These readings are comparable to what many people measure every day using Oura rings, Whoop straps, etc.

 

Importantly, no breathing was performed on the nights of the measurements.  So, any observed changes in vagal tone indicate changes in resting autonomic nervous system activity.

 

 

3. What Were the Major Findings?

 

The take-home findings were that 15 minutes of slow breathing before bed:

  • Significantly improved subjective sleep quality on the PSQI scale.

  • Significantly increased nighttime vagal tone measured via HF-HRV.

  • Increased (but not significantly) morning vagal tone.

 

Moreover, increases in vagal tone were correlated with changes in sleep quality: As vagal tone increased, sleep quality got better. This is associative, not causal, but still interesting nonetheless.

 

 

4. Why Do These Results Matter?

 

These results are meaningful because sleep is essential to basically every biological function, and here we learn that doing 15 minutes of slow breathing provides a free and effective way to improve sleep quality.

 

Moreover, the increase in morning and nighttime vagal tone is meaningful because vagal tone isn’t just “vagal tone.”  It’s better cognitive function, better social skills, better emotional and stress regulation, and better overall health.

 

 

 

1 BIG TAKEAWAY

 

Fifteen minutes of slow breathing (6 breaths per minute) before bed for 30 days improves sleep quality and increases vagal tone.

 

 

 

1 PRACTICAL APPLICATION

 

To implement the findings of this study in your life, aim to perform 15 minutes of slow breathing before bed.  Use a slightly longer exhale than inhale, which will aid in increasing vagal activity.  This study used a 4.5-second inhale and 5.5-second exhale, but we can use 4:6 (or a variation that’s comfortable for you) to make it easier on most breathing apps. 

 

Moreover, my hunch is that basically any ratio focused on parasympathetic activation will work, so if you enjoy the 4-7-8 breath or another alternative, it’s reasonable to assume you’ll still achieve similar results.

 

Enjoy sleeping and feeling better with this simple nighttime routine.