Heart Rate Variability Biofeedback in Security Forces (GNR-HRVB)

Egas Moniz - Cooperativa de Ensino Superior, CRL

Status: Enrolling

Conditions: Burnout; Well-Being, Psychological; Psychological Distress

Treatments: Behavioral: Heart Rate Variability Biofeedback (HRV-BFB) Training

Study type: Interventional

Funder types: Other

Identifiers

NCT07386951

PT-214/25

Details and patient eligibility

About

This exploratory study evaluates the effectiveness of a 12-session Heart Rate Variability Biofeedback (HRV-BFB) protocol in reducing distress and burnout while promoting psychological well-being among Portuguese National Republican Guard (GNR) professionals. Exposed to high occupational stress from unpredictable risks, shift work, and limited resources, these individuals face elevated vulnerability to chronic stress outcomes. The intervention leverages real-time HRV feedback to enhance autonomic regulation, breathing techniques, and emotional self-regulation.

Full description

Security forces like the GNR play a critical role in public safety but endure chronic stress from violence exposure, rapid decisions, shift rotations, and institutional resource shortages, heightening risks of distress, burnout, and impaired well-being (Miller, 2023; Purba & Demou, 2019; Galanis et al., 2021; Pereira et al., 2023). Distress arises when perceived threats exceed coping resources, leading to persistent negative emotions and health disruptions (Lazarus & Folkman, 1984; Cohen et al., 2007). Burnout manifests as exhaustion, mental distancing, and reduced efficacy from unmanaged chronic stress (Maslach & Jackson, 1981; WHO, 2022), with organizational impacts including absenteeism and eroded public trust (Bakker & Demerouti, 2023). Psychological well-being encompasses multidimensional aspects like autonomy, relationships, and purpose beyond mere absence of illness (Ryff, 1989). Traditional interventions face barriers such as stigma and access issues in rural GNR contexts, necessitating flexible, self-administered tools (Iversen et al., 2005; Bishopp & Boots, 2014).

Intervention: HRV-BFB Protocol HRV-BFB trains participants to consciously modulate physiological responses via real-time monitoring of heart rate variability (HRV), reflecting sympathetic-parasympathetic balance (Lehrer & Gevirtz, 2014; Schwartz & Andrasik, 2017). Low HRV links to mental health risks, while training targets resonance frequency breathing (~6 breaths/min or 0.1 Hz) to boost HRV amplitude, cardiac coherence, and baroreflex strength (Vaschillo et al., 2006; Song & Lehrer, 2003). Delivered autonomously via app post-initial guidance, the 12-session protocol requires no daily clinician oversight, enhancing accessibility for dispersed GNR personnel (Herhaus et al., 2022; Vagedes et al., 2015). Evidence shows HRV-BFB reduces stress, anxiety, depression, and burnout while fostering well-being in high-stress groups like emergency workers (Eddie et al., 2015; Brinkmann et al., 2020b; Sveinsdóttir et al., 2025).

Study Objectives This exploratory trial tests whether HRV-BFB significantly lowers distress (multidimensional: physical, cognitive, emotional, behavioral), burnout levels, and boosts psychological well-being in GNR professionals. It aims to inform scalable interventions tailored to Portuguese police realities, addressing gaps in institutional support.

Enrollment: 50 estimated patients

Sex: All

Ages: 18 to 55 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

1. Operational military personnel of the Guarda Nacional Republicana (GNR) performing security, patrol, criminal investigation, or road safety duties
2. Any military rank or professional category within operational roles
3. Age between 18 and 55 years, inclusive
4. Both males and females
5. Capable of providing informed consent in Portuguese language

Exclusion criteria

1. Extended sick leave or medical absence
2. Currently involved in serious disciplinary proceedings
3. Use, modification, or initiation of psychotropic medication (including antidepressants, anti-anxiety medications, antipsychotics, mood stabilizers) within the past 6 months

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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50 participants in 2 patient groups

HRV Biofeedback Training

Experimental group

Description:

Participants receive 12 individual sessions of heart rate variability biofeedback (HRV-BFB) over 4 weeks (one 12-minute session every 2 days). Training is delivered using a chest-worn ECG sensor (eSense Pulse) connected to a mobile application that provides real-time visual feedback.

Treatment:

Behavioral: Heart Rate Variability Biofeedback (HRV-BFB) Training

Control: No Intervention

No Intervention group

Description:

Participants receive no active intervention during the 4-week study intervention period and continue their usual duties and routines. They complete the same assessment schedule as the experimental group at baseline, 4 weeks, and 10 weeks. After completion of the final follow-up assessment, they are offered the opportunity to receive the HRV biofeedback training protocol.