Age-Matched Comparison of Elite and Non-elite Military Performers during Free Living and Intense Operational Stress

摘要

A useful approach to quantifying factors that influence human performance involves the classification and comparison of so-called 'elite' and 'non-elite' performers. In this pilot study, the authors classified 6 graduates of the Basic Underwater Demolition/SEAL training program as elite and compared them to 6 age-matched non-elite military personnel on key aspects of physiological and psychological function during free living and in response to intense military stress. Participants completed measures of perceived stress and anger during daily living. Diurnal variation in heart rate (a marker of parasympathetic cardiac control) was measured via ambulatory holter monitoring. Participants were then followed during stressful survival training, where salivary cortisol was sampled during a mock-captivity exercise, and acute stress responses were examined via self-report. Results show that elite performers reported less perceived stress (p=.07) during daily living. Group differences in diurnal cardiac function were observed, and elite performers demonstrated more substantial nocturnal heart rate dipping (29% versus 21%; p=.08). Although elite performers produced nearly identical cortisol responses to an overt high-stress encounter during mock captivity, they generated much lower cortisol responses in the absence of overt challenge (p=.003) -- a phenomenon the authors termed 'selectivity.' Finally, elite performers reported fewer subjective stress responses to mock captivity (p=.08) than their non- elite counterparts. Elite and non-elite military performers differ across several criteria both during free living and in response to intense stress. Of particular importance, elite performers demonstrate greater 'selectivity' in response to overt stressors -- a possible marker of adaptability or resilience. These findings have broad implications for the identification, selection, and training of elite performers in high-stress occupations.