Episodes of momentary resilience in daily life are associated with HRV reductions to stressful operations in firefighters: an ambulatory assessment approach using bayesian multilevel modeling

Background: Resilience is discussed to constitute a protective buffer against stress, thus fostering health. Methods: This study aimed to assess resilience both via traditional questionnaire and in everyday life on a momentary basis, and to relate these measures to autonomic functioning (heart rate variability, HRV) in 38 male firefighters during a weekday. Stressful operations, non-stressful operations and routine work at the firestation were coded during 24 hours. Momentary negative affect, feelings of resilience, and HRV were recorded via ecological momentary assessment. Findings: Questionnaire-assessed resilience was significantly positively associated with aggregated momentary resilience (r = .58, p < .001), but unrelated to HRV. However, controlling for multiple confounders (e.g., age, smoking, bodily movement, waist-to-height ratio) momentary resilience was associated with attenuated HRV and lower negative affect during stressful encounters only. Discussion: The findings suggest that momentary feelings of resilience are accompanied by vagal withdrawal to stress, possibly indicating psychological flexibility and adaptive responding to stress.