Enhancing Physiological Complexity Through Mindfulness: A Wearable-Based Intervention for First Responders and Their Partners.
Thurmon E Lockhart, Rahul Soangra, Christopher Frames, Sun-Kyung Lee, Amberlee Martin, Susanne Lee, Abigail H. Gewirtz
Healthcare June 1, 2026 DOI: 10.3390/healthcare14111532 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Longitudinal Peer reviewed |
|---|---|
| Sample size | 87 |
| Population | First responders |
| Interventions | Mindfulness message prompt to access an audio exercise |
| Duration | One-month intervention |
| Topics | Meditation |
| Keywords | Hrv complexity Autonomic regulation Ecological momentary assessment First responders Heart rate variability Multiscale entropy Sample entropy Stress management Wearable technology |
| Key findings | A wearable-based mindfulness intervention significantly improved HRV complexity metrics, reflecting enhanced autonomic regulation and adaptive capacity in first responders. |
Abstract
Background/Objectives: First responders frequently encounter high-stress environments that challenge physiological resilience and autonomic regulation. Heart rate variability (HRV) complexity is a critical marker of adaptive capacity and stress regulation. This study assessed the impact of a wearable-based mindfulness intervention on HRV complexity among first responders using a smartwatch.
Methods: A total of 87 first responders participated in a one-month wearable-based intervention. Participants wore Garmin Vivosmart 5 devices to continuously collect PPG data (photoplethysmogram), focusing on beat-to-beat intervals (BBIs). The intervention involved daily Ecological Momentary Assessments (EMAs) and individual randomization to either a mindfulness message, a prompt to access an audio exercise, or no-treatment/control; interventions were delivered via the MYAPT.MIND mobile application. HRV metrics, including Sample Entropy, Multiscale Entropy (MSE), Recurrence Rate (RR), and Determinism (Det), were analyzed pre- and post-intervention/control using paired-samples t-tests.
Results: Significant improvements were observed in HRV complexity metrics post-intervention. Sample Entropy increased (M = 1.42, SD = 0.11) compared to pre-intervention (M = 1.39, SD = 0.10; p = 0.007). MSE also showed significant gains (p = 0.038), particularly at lower scales, indicating enhanced short-term autonomic flexibility. Reductions were noted in RR (p = 0.025) and Det (p = 0.018), suggesting improved cardiovascular adaptability and reduced physiological rigidity. Other traditional time-domain metrics, such as Mean HR, SDNN, and RMSSD, did not exhibit significant changes.
Conclusions: The wearable-based intervention significantly enhanced HRV complexity, reflecting improved autonomic regulation and adaptive capacity in first responders. These findings support the integration of digital mindfulness strategies for stress management in high-risk occupations. Future research should explore the longitudinal effects and mechanisms mediating these autonomic adaptations.
Comparable studies
Other randomized controlled trials on meditation, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Alterations in Brain and Immune Function Produced by Mindfulness Meditation Healthy employees in a work environment | 2003 | Randomized controlled trial | n = 41 |
| Prevention of relapse/recurrence in major depression by mindfulness-based cognitive therapy. Recovered recurrently depressed patients | 2000 | Randomized controlled trial | n = 145 |
| Open hearts build lives: Positive emotions, induced through loving-kindness meditation, build consequential personal resources. Working adults | 2008 | Randomized controlled trial | n = 139 |
| Short-term meditation training improves attention and self-regulation Undergraduate Chinese students | 2007 | Randomized controlled trial | n = 40 |
| Mindfulness-Based Cognitive Therapy for Depression: Replication and Exploration of Differential Relapse Prevention Effects. Recovered recurrently depressed patients | 2004 | Randomized controlled trial | n = 73 |
Citations in the library
Cites 12
- Mindfulness meditation training alters stress-related amygdala resting state functional connectivity: a randomized controlled trial Social Cognitive and Affective Neuroscience June 5, 2015
- App‐based mindfulness meditation reduces perceived stress and improves self‐regulation in working university students: A randomised controlled trial Applied Psychology: Health and Well-Being December 27, 2021
- The meditation app revolution. American Psychologist August 7, 2025
- Incorporating biofeedback into the Mindfulness in Motion Intervention for health care professionals: Impact on sleep and stress. Explore 2024
- Can heart rate variability demonstrate the effects and the levels of mindfulness? A repeated-measures study on experienced and novice mindfulness practitioners. BMC Complementary Medicine and Therapies July 3, 2025
and 7 more in the library