Cardiac Efficiency as a Marker of Firefighter Expertise: Heart Rate Variability Monitoring in Realistic Search-and-Rescue Training

Expertise in high-stakes occupations is typically evaluated through performance outcomes, potentially neglecting physiological efficiency—a dimension critical for career longevity in physically demanding work. We investigated whether expert firefighters achieve comparable task performance with lower cardiovascular activation and faster autonomic recovery than novices during realistic search-and-rescue operations. Twenty-two male firefighters completed navigation tasks in a high-fidelity training facility under operational conditions (complete darkness, full protective equipment). Using a 2 × 2 quasi-experimental design, we manipulated navigation strategies (route-based vs. survey-based) and continuously recorded heart rate variability across baseline, execution, and recovery periods. Contrary to conventional expertise models, experts and novices demonstrated equivalent task completion times and accuracy. However, experts exhibited substantially lower heart rate elevation during tasks and 46% greater parasympathetic recovery post-task. Critically, an expertise-by-strategy interaction revealed that experts’ efficiency advantages were magnified when employing route-based strategies aligned with training protocols, whereas novices showed no strategy-dependent differences. These findings suggest physiological efficiency represents a distinct expertise component overlooked by performance-only assessments. Heart rate variability monitoring may identify individuals requiring additional skill consolidation or recovery support.