A short mindfulness session may do more than create a temporary feeling of calm. New research from San José State University and the University at Albany, State University of New York suggests that even two brief mindfulness sessions can produce measurable changes in how several parts of the autonomic nervous system function together.
The study, published in Physiology & Behavior on August 1, 2026, examined 91 young adults, with 44 assigned to a brief mindfulness-based intervention and 47 to an audiobook control condition. Researchers measured respiratory sinus arrhythmia (RSA), skin conductance level (SCL), systolic and diastolic blood pressure, and responses to a standardized psychological stress test.
The findings are particularly interesting because the researchers did not treat stress as a single biological signal. Instead, they examined several systems simultaneously and asked whether mindfulness changed the coordination between them.
That produced a more nuanced result than simply saying meditation lowers stress. The mindfulness group showed greater RSA augmentation during the intervention, lower skin conductance during the second session, and lower blood pressure following the mindfulness practice. After a stressful laboratory task, participants who completed mindfulness also had lower diastolic blood pressure than controls.
The study does not establish that two meditation sessions can permanently alter the nervous system. It does, however, add evidence that brief mindfulness can produce measurable physiological changes—and that looking at several systems together may reveal effects that are missed when researchers examine only one biomarker.
Why The Autonomic Nervous System Matters
The autonomic nervous system regulates many processes that operate without conscious control, including cardiovascular activity, sweating, digestion and aspects of the body’s response to stress.
It is commonly discussed in terms of two interacting branches: the sympathetic nervous system, which contributes to mobilization and arousal, and the parasympathetic nervous system, which supports recovery and regulation. The relationship between these systems is more complicated than a simple “fight-or-flight versus rest-and-digest” model, however.
The new study focused on two physiological indicators that provide different windows into autonomic activity.
Respiratory sinus arrhythmia, or RSA, reflects changes in heart rate associated with breathing and is commonly used as an index of parasympathetic or vagal cardiac regulation. Skin conductance level, or SCL, reflects electrical changes in the skin associated largely with sympathetic nervous-system activity.
That combination allowed researchers to examine whether mindfulness influenced cardiovascular and sympathetic activity independently—or whether the two systems became better coordinated.
For readers interested in the broader science behind mindfulness and stress, this distinction is important. Mindfulness research increasingly asks not only whether people report feeling better but also whether measurable physiological processes change alongside those experiences.
The Study Included 91 Young Adults
The research team included Li Shen Chong, a psychologist at San José State University, along with Rachel C. Bucher, Edward Merritt and Elana B. Gordis of the University at Albany, State University of New York and other affiliated institutions.
Researchers recruited 91 undergraduate students, with an average age of approximately 18.8 years. Forty-four participants were assigned to the brief mindfulness-based intervention and 47 to the control group.
There was an important distinction between enrollment and completion. While 91 students attended the first laboratory visit, only 61 participants attended both visits—28 from the mindfulness group and 33 from the control group.
The researchers used sex-stratified randomization and controlled for gender and racial minoritized status in their analyses because those variables were associated with some physiological measures.
This was not a large clinical trial, and participants were predominantly young adults recruited through a university psychology research pool. That limits how broadly the findings can be generalized.
But the controlled laboratory design allowed the researchers to measure physiological changes under carefully defined conditions.
What Did The Mindfulness Intervention Include?
The intervention was deliberately brief.
Participants listened to a series of guided practices from the UCLA Mindful Awareness Research Center, totaling approximately 15 minutes. The sequence included:
- A five-minute breathing meditation
- A seven-minute meditation for working with difficulties
- A three-minute body scan
The practices directed participants toward awareness of breathing, thoughts, emotions and bodily sensations.
The control group listened to a 15-minute fictional audiobook instead.
That comparison is useful because participants in both groups spent the same amount of time sitting quietly and listening to audio. The primary difference was therefore the content of the intervention rather than simply taking a break from activity.
This is an important methodological feature for research into mindfulness techniques, because simply stopping work and sitting somewhere quiet could itself influence physiological measures.
Researchers Measured The Body During Meditation
The participants were connected to physiological equipment while they completed either the mindfulness intervention or the audiobook condition.
Researchers recorded ECG and respiration data to calculate RSA. They also measured SCL and collected repeated blood-pressure readings.
The protocol involved two laboratory visits separated by two to four days. During the second visit, participants completed the intervention and then underwent a standardized psychological stress test.
This design allowed researchers to ask two different questions.
First, what happens to the nervous system while someone is actively practicing mindfulness?
Second, does that brief exposure appear to influence the body’s response after the person encounters a stressful situation?
Those questions are not interchangeable.
A person can experience physiological changes while meditating without those changes necessarily carrying over into a stressful event later.
The study’s multisystem design was intended to examine that possibility.
RSA Increased During Brief Mindfulness
One of the clearest findings involved respiratory sinus arrhythmia.
Compared with the control condition, participants in the mindfulness group showed greater RSA augmentation during the intervention. The effect appeared across the two intervention sessions, although the researchers described the effect as relatively small.
The estimated effect size for RSA induction during the second visit was d = 0.46, while the first visit produced an effect size of d = 0.42.
This suggests that the brief mindfulness exercises were associated with greater parasympathetic-related cardiac activity during practice.
However, it would be misleading to translate that directly into a statement that mindfulness “strengthens the vagus nerve” or permanently improves nervous-system health.
RSA is a physiological indicator, not a direct measurement of overall wellness.
The researchers themselves emphasize the importance of context. Autonomic activity can change during rest, mindfulness and stressful situations for different reasons, making it difficult to interpret a single measurement without knowing when and how it was collected.
Skin Conductance Told A Different Story
The second major physiological measure was skin conductance level.
During the second mindfulness session, the intervention group showed significantly lower SCL than the control group. The statistical analysis produced p = 0.001 and an effect size of approximately d = 0.76, a substantially larger effect than the RSA differences.
The first session did not produce a statistically significant difference in SCL.
That detail is easy to overlook but scientifically important.
The findings suggest that the two systems did not necessarily respond at exactly the same speed.
The researchers interpreted the results as evidence that brief mindfulness may activate parasympathetic processes while reducing sympathetic-related activity during the intervention, with some of those effects becoming clearer after the second exposure.
This also provides an argument against viewing mindfulness as an instant “reset button.”
The physiological response was more specific and context-dependent.
Blood Pressure Also Changed
Blood pressure provided another important measurement.
After the mindfulness intervention, participants showed greater reductions in systolic blood pressure compared with controls. The study also found that participants in the mindfulness group had significantly lower diastolic blood pressure immediately after the Trier Social Stress Test.
The post-stressor diastolic blood-pressure comparison produced p = 0.02 and an effect size of d = 0.50.
That is particularly interesting because the blood-pressure difference occurred after participants had been exposed to a stressful situation.
The researchers interpreted the lower post-stressor diastolic pressure as tentative evidence that brief mindfulness may influence cardiovascular regulation outside the meditation period itself.
The word “tentative” matters.
This was a short-term laboratory measurement, not evidence that mindfulness can treat hypertension.
The American Heart Association’s current blood-pressure guidance also places meditation and controlled breathing among lifestyle or complementary approaches rather than substitutes for clinically indicated treatment.
For people with diagnosed high blood pressure, these findings should therefore be viewed as part of the broader evidence on stress management rather than a reason to discontinue medication or medical monitoring.
The Stress Test Was Designed To Make Participants Uncomfortable
After the second intervention, participants completed the Trier Social Stress Test, a widely used laboratory method for studying responses to social-evaluative stress.
Participants first had five minutes to prepare a speech about why they were the best candidate for an ideal job. They then delivered the speech for four minutes while two research assistants maintained neutral expressions and provided little feedback.
After the speech, participants completed a four-minute verbal arithmetic task. They were instructed to count backward from 2,023 in increments of 17. If they stopped, researchers prompted them to continue.
The setup was designed to create uncertainty, evaluation and performance pressure.
That matters because the study was not simply testing whether participants could relax in a quiet room.
It was testing whether a brief mindfulness intervention was followed by measurable differences when the participants encountered a controlled stressor.
Mindfulness Changed Coordination Between Systems
This may be the most scientifically interesting part of the study.
Researchers found that the mindfulness group displayed a reciprocal relationship between RSA and SCL during the stress task. In simplified terms, increases in one measure were associated with decreases in the other.
The control group displayed a different pattern, with RSA and SCL showing a positive association instead.
The researchers describe this as a difference in multisystem autonomic coordination.
Why does that matter?
Because a stress response is not produced by one biological system acting alone.
The heart, skin, breathing, blood pressure and other physiological systems respond simultaneously, but they do not necessarily respond in identical ways.
Studying these systems together can therefore reveal patterns that disappear when researchers analyze one measurement at a time.
That is the central contribution of this research.
The Study Did Not Find Every Expected Effect
The findings were not uniformly positive across all measurements.
Researchers did not find significant differences between the groups for RSA reactivity or SCL reactivity during the Trier Social Stress Test itself. In other words, the groups did not differ significantly in the magnitude of those specific physiological changes during the stressor.
The blood-pressure findings were different.
The mindfulness group had lower post-stressor diastolic blood pressure, suggesting that cardiovascular effects may have persisted into the period immediately following the stressor even though the branch-specific RSA and SCL stress reactivity measures were not significantly different.
This distinction reinforces the study’s central message.
Mindfulness did not simply make every stress-related measurement move in the same direction.
Instead, it appeared to influence some aspects of autonomic regulation and coordination while leaving others unchanged.
That is a more complicated finding—but also a more useful one.
Why Two Sessions Matter
Another unusual feature of the research is how little intervention was required.
The study did not involve an eight-week mindfulness course, months of meditation practice or intensive retreat training.
Participants completed just two 15-minute sessions, separated by several days.
The researchers specifically designed the protocol to examine early-stage physiological adaptations, rather than the cumulative effects associated with long-term mindfulness training.
That makes the results relevant to the growing interest in brief mindfulness programs.
Universities, employers and digital wellness platforms increasingly favor interventions that can be completed in minutes rather than requiring long daily sessions.
But the study should not be interpreted as evidence that two sessions produce lasting changes.
The authors explicitly identify the short intervention period as a limitation and call for additional sessions and longer follow-up research.
The current findings show an early physiological signal, not a demonstrated long-term transformation.
What Makes This Research Different From Earlier Mindfulness Studies?
Many mindfulness studies focus on one outcome.
Researchers might measure perceived stress, cortisol, heart rate, brain activity or a psychological questionnaire.
That approach can produce useful information, but it can also create conflicting results.
A person may report feeling calmer while a physiological measure remains unchanged. Another study might find a cardiovascular effect without a corresponding change in subjective stress.
The researchers behind the new study argue that examining several autonomic systems together may help explain some of those inconsistencies.
The research therefore shifts the question from:
“Does mindfulness reduce stress?”
to something more precise:
“How does brief mindfulness alter the coordination of multiple physiological systems during different states?”
That is a much more sophisticated question.
It also fits the direction of current psychophysiology research, where researchers increasingly examine interactions between systems rather than isolated biomarkers.
There Are Important Limits To The Findings
The study’s results are promising, but several limitations should shape how they are interpreted.
First, the sample consisted of young adults recruited from an undergraduate psychology research pool. The findings may not apply in the same way to older adults, people with cardiovascular disease, people with diagnosed anxiety disorders, or individuals experiencing chronic occupational stress.
Second, only 61 of the 91 participants completed both laboratory visits. That reduces the amount of repeated-measures data available for some analyses.
Third, the researchers did not measure participants’ previous mindfulness experience. Someone who had already practiced meditation could respond differently from someone encountering mindfulness for the first time.
Fourth, the researchers did not monitor informal mindfulness practice between sessions.
Finally, the study measured short-term physiological effects. It cannot establish whether the changes persist for weeks, months or years.
These limitations do not invalidate the findings.
They define what the study can legitimately tell us.
Could Brief Mindfulness Become A Practical Stress Tool?
The practical appeal is obvious.
The intervention required only 15 minutes, used recorded guidance and did not require specialized equipment. The researchers note that audio-based mindfulness may be more accessible and less expensive than person-led programs.
That could make short mindfulness sessions attractive in settings where time and staffing are limited.
A university could potentially incorporate a 15-minute guided practice into student wellness programming. An employer could offer brief sessions during high-demand periods. A person could use an audio recording before a stressful event.
But accessibility should not be confused with universal effectiveness.
The study shows that brief mindfulness can produce measurable physiological effects under controlled conditions. It does not show that every person will experience the same response.
Individual differences in baseline stress, prior meditation experience, sleep, medication use, physical health and expectations may all influence outcomes.
The Next Question Is Whether The Changes Last
The most important unanswered question is persistence.
If two 15-minute sessions can change RSA, SCL and blood pressure in the laboratory, what happens after ten sessions?
What happens after eight weeks?
And, more importantly, does repeated practice change how someone responds to stressful events outside the laboratory?
Those questions remain open.
Future studies could track participants for several months and combine physiological measurements with daily stress reports, sleep measurements and real-world activity monitoring.
Researchers could also compare different forms of mindfulness rather than using one standardized audio sequence.
Another important comparison would involve people experiencing chronic stress rather than primarily young university students.
If similar multisystem changes appeared across different age groups and stress profiles, the evidence for broader applications would become considerably stronger.
A More Precise Picture Of What Mindfulness Does
The new research from Li Shen Chong, Rachel C. Bucher, Edward Merritt and Elana B. Gordis does not demonstrate that mindfulness permanently rewires the nervous system.
It demonstrates something narrower and scientifically valuable.
After two brief mindfulness sessions, young adults showed measurable differences in several autonomic indicators. RSA increased during mindfulness, SCL was lower during the second mindfulness session, and blood pressure showed favorable changes both after the intervention and immediately following a laboratory stressor. The mindfulness group also demonstrated a different pattern of coordination between parasympathetic-related RSA and sympathetic-related SCL during stress.
At the same time, RSA and SCL reactivity during the stress test itself did not significantly differ between groups.
That mixed pattern is important.
It suggests that mindfulness may influence how physiological systems coordinate, rather than simply turning the body’s stress response down across the board.
For anyone following the growth of evidence-based mindfulness, that may be the more meaningful development.
The future of mindfulness research is moving beyond the question of whether meditation makes people feel relaxed. Researchers are increasingly asking what happens inside the body, when those changes occur, how different physiological systems interact, and whether brief interventions can influence the way people recover from stress.
Two 15-minute sessions are not enough to establish a long-term health intervention.
But they may be enough to show researchers where to look next.