Heart Rate Variability Biofeedback in Security Forces

Official title

Heart Rate Variability Biofeedback in Distress Regulation and Burnout Prevention Among Security Forces

Overview

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.

Detailed 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. Distress arises when perceived threats exceed coping resources, leading to persistent negative emotions and health disruptions. Burnout manifests as exhaustion, mental distancing, and reduced efficacy from unmanaged chronic stress, with organizational impacts including absenteeism and eroded public trust. Psychological well-being encompasses multidimensional aspects like autonomy, relationships, and purpose beyond mere absence of illness. Traditional interventions face barriers such as stigma and access issues in rural GNR contexts, necessitating flexible, self-administered tools.

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. 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. Delivered autonomously via app post-initial guidance, the 12-session protocol requires no daily clinician oversight, enhancing accessibility for dispersed GNR personnel. Evidence shows HRV-BFB reduces stress, anxiety, depression, and burnout while fostering well-being in high-stress groups like emergency workers.

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.

Interventions

• Behavioral Heart Rate Variability Biofeedback (HRV-BFB) Training
  Participants receive a structured heart rate variability biofeedback (HRV-BFB) training protocol delivered over 4 weeks. The intervention uses a portable chest-worn ECG sensor (eSense Pulse) connected via Bluetooth to a mobile application that provides real-time visual feedback of heart rate variability. Each participant completes 12 individual sessions of 12 minutes each (one session every 2 days). Sessions take place in a quiet room and follow a standardized format: a brief preparation phase,

Primary outcome measures

• Change in Psychological Distress (Kessler Psychological Distress Scale - K10) [Time frame: Baseline (Week 0), Post-intervention (Week 4), Follow-up (Week 10)]
• Change in Occupational Burnout (Burnout Assessment Tool - BAT-12) [Time frame: Baseline (Week 0), Post-intervention (Week 4), Follow-up (Week 10)]
• Change in Psychological Well-Being (WHO-5 Well-Being Index) [Time frame: Baseline (Week 0), Post-intervention (Week 4), Follow-up (Week 10)]

Secondary outcome measures (3)

• SDNN (Standard Deviation of NN Intervals) - Heart Rate Variability [Time frame: Baseline (Week 0), after each of 12 training sessions]
• RMSSD (Root Mean Square of Successive Differences) - Parasympathetic Activity [Time frame: Baseline (Week 0), after each of 12 training sessions]
• Stress Index - Autonomic Balance Indicator [Time frame: Baseline (Week 0), after each of 12 training sessions]

Eligibility criteria

Inclusion criteria

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

Exclusion criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Prevention

Study locations

Portugal · 1 center

• GNR - Comando Terrritorial de Setúbal (GNR - Setubal Territorial Command Centre) — Setúbal

Identifiers

NCT: NCT07386951 · PT-214/25

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗