Breathwork and Cold Water at a French Festival Linked to Lower Anxiety Scores

At a three-day outdoor festival in France, where participants cycled through guided breathwork sessions, icy cold-water immersion and group movement practices, researchers observed something intriguing: people who completed psychological questionnaires before and after the event reported measurably lower levels of trait anxiety afterward. The study, published in Discover Psychology, offers one of the first naturalistic examinations of how these increasingly popular practices might affect psychological dispositions when delivered together in a real-world, multi-day format rather than in the sterile confines of a laboratory.

The research team, led by Carina Berglund of Nantes Université’s Movement – Interactions – Performance laboratory, together with colleagues from Université Lumière Lyon 2 and Université d’Angers, focused on the Festival du Froid, held in France in 2024. Unlike controlled intervention trials, this was a field study embedded in a genuine community event, capturing the full context in which people actually engage with breathwork and cold exposure: outdoors, in groups, over consecutive days, and amid the social energy of a festival. This ecological realism is precisely what most existing evidence lacks, since the bulk of research on cold exposure and breathwork has examined acute physiological responses or momentary mood shifts in single sessions.

The investigators distributed surveys before and after the festival and received 85 responses in total. Of these, 19 participants, or 22 percent, provided complete paired data from both time points, forming the analytical sample. The primary outcome was trait anxiety, measured with the State-Trait Anxiety Inventory’s trait subscale, a widely used instrument that assesses the tendency to experience anxiety as a relatively stable characteristic. The researchers also tracked resilience and cognitive emotion regulation, expecting that these psychological resources might shift alongside anxiety, though that is not what the data ultimately showed.

The headline finding was a statistically significant drop in trait anxiety scores. Before the festival, participants averaged 42.6 points with a standard deviation of 7.8; afterward, the average fell to 39.8 with a standard deviation of 8.3, a reduction of 6.6 percent. The mean difference was 2.79 points, with a 95 percent confidence interval ranging from 0.91 to 4.67. A Wilcoxon signed-rank test, appropriate for non-normally distributed paired data, yielded a p-value of .002, and the standardized effect size, Hedges’ g, came out at 0.68 with a confidence interval of 0.19 to 1.16, which by conventional benchmarks represents a moderate-to-large effect. Importantly, 16 of the 19 participants showed reduced or stable scores, suggesting the change was not driven by a handful of dramatic responders.

What makes this result conceptually interesting is the target of the measurement. Trait anxiety has traditionally been treated as a fixed disposition, something stable across situations and resistant to brief interventions. The authors instead interpret the STAI-Trait score as a marker of negative affectivity, a vulnerability to experiencing negative emotions that may be more malleable than the label trait implies. Viewed through this lens, a multi-day immersive experience combining physiological stressors with communal practices could plausibly shift this vulnerability in the short term, even if longer-lasting change remains an open question that the study was not designed to answer.

The physiological rationale for such an effect is grounded in plausible mechanisms, even though the study did not measure them directly. Cold-water immersion triggers a robust stress response, acutely elevating catecholamines and activating the sympathetic nervous system, and repeated controlled exposure has been hypothesized to improve top-down regulation of autonomic arousal. Deliberate breathwork practices, particularly those involving slow or patterned breathing, are associated with increased vagal tone and reduced subjective tension, while some intense hyperventilation-based protocols produce transient states of altered arousal that participants often describe as cathartic. Group movement and shared physical challenge add further layers, including social bonding, collective efficacy and the mood effects of sustained outdoor activity. A festival format stacks all of these elements together, which makes it impossible to isolate which ingredient, or which combination, produced the observed change.

Indeed, the authors are explicit that the study is exploratory and that no causal claims can be made. The design lacked a control group, so regression to the mean, expectancy effects, the simple passage of time, or the general experience of attending a restorative social event could all account for part of the improvement. The completion rate was low, with only 22 percent of respondents providing paired data, and the sample was small and self-selected, composed of people motivated enough to attend a cold-exposure festival and diligent enough to complete both surveys. Such participants may differ systematically from the general population in baseline anxiety, openness to experience and enthusiasm for the practices involved, all of which limit generalizability.

Two secondary findings add nuance to the picture. First, satisfaction with the festival was uniformly high, indicating strong acceptability of the format; this matters for any future intervention research, since adherence and enjoyment are prerequisites for scaling such programs. Second, and perhaps more surprising, neither resilience nor cognitive emotion regulation changed from before to after the event. If the anxiety reduction had been driven by a genuine strengthening of coping resources, one might expect these measures to move in parallel. Their stability suggests instead that the effect may be closer to an acute reduction in negative affective vulnerability, a temporary recalibration of emotional baseline, rather than a durable upgrade in psychological skills. The authors themselves characterize the finding as preliminary evidence that the festival format is associated with an acute reduction in negative affective vulnerability alongside high acceptability.

The study was conducted within the CNRS Collab Inspire research collaboration agreement between CNRS UMR 6590 ESO and Inspire Potential, with Mathilde Plard serving as scientific lead, and Berglund’s doctoral research is supported by the Horizon Europe Breath program. The protocol received approval from the Ethics Committee for Research of Nantes Université, and the study was performed in accordance with the Declaration of Helsinki. Participation was voluntary and anonymous, with responses linked only by a self-chosen four-digit code, and participants could withdraw at any time without consequence. The sponsors had no role in data collection, analysis or manuscript preparation, and the authors declare no competing interests.

For the growing audience drawn to breathwork circles, ice baths and cold-water plunges, the study offers a cautiously encouraging signal rather than a prescription. It suggests that a multi-day, community-based format combining these practices is safe enough, enjoyable enough and potentially effective enough to justify more rigorous investigation, ideally with randomized or matched control conditions, larger samples, longer follow-up periods and physiological monitoring to identify mechanisms. Until such trials arrive, the Festival du Froid data stand as an intriguing naturalistic data point: a modest but consistent drop in anxiety vulnerability among ordinary people who spent three days breathing, moving and shivering together in the French outdoors, and a reminder that some of the most popular wellness practices of the moment are only now beginning to meet the standards of careful psychological science.

Subject of Research: Psychological effects of a multiday breathwork and cold-water immersion festival on trait anxiety

Article Title: A multiday outdoor festival combining breathwork and cold water immersion is associated with reduced trait anxiety in a naturalistic pre-post study

Article References: Berglund, C., Hallez, Q., Deschamps, T., & Plard, M. (2026). A multiday outdoor festival combining breathwork and cold water immersion is associated with reduced trait anxiety in a naturalistic pre-post study. Discover Psychology. https://doi.org/10.1007/s44202-026-00914-1

Image Credits: AI Generated

DOI: 10.1007/s44202-026-00914-1

Keywords: breathwork, cold-water immersion, trait anxiety, negative affectivity, naturalistic pre-post study, festival, mental health, emotion regulation, resilience, well-being, stress response, Discover Psychology