Immunoendocrine interactions and T cell proliferation responses to layered physical and psychological stressors

Abstract

Introduction: Military training environments are rigorous requiring service men and women to endure not only physical and psychological stress but also sleep deprivation, caloric restrictions, and severe thermic challenges. Exposure to these layered stressors are thought to improve human performance by acclimating the individuals to “real-world” operational stressors. It is difficult for scientists to identify pertinent immunoendocrine interactions occurring in layered stress environments because of considerable logistical constraints involving location of and access to affected personnel. The convention has been to use immunoendocrine responses induced by various exercise regimens as platforms to generalize results to the layered, and more exaggerated stress environments of military training. Methods: Three distinct experiments were conducted to understand immunoendocrine interactions resulting from layered stress environments. The first project investigated T cell proliferation following concurrent aerobic and resistance training as well as assessing changes in measures of proliferation following delayed cell isolation protocols. The second project examined whether the exercise models we use to generalize to military experiences are accurate. Eight healthy males underwent a high intensity training session combining physical and psychological stress similar to that experience in military operational training. A control group of 8 subjects participated in a moderate intensity session as comparison. Blood parameters were measured at Pre, Post, 1 hr, 4hr, and 6hr. The third project was an observational study examining immunoendocrine responses to the Marine Corps Martial Arts Training Program (MCMAP). Thirty-six newly enlisted, male Marines were observed three times over a nine-week period at Fort Leonard Wood, MO. Blood parameters were measured prior to training, Post training and at 15 min intervals out to 1 hr after training cessation. Conclusions: Immunoendocrine alterations following MCMAP sessions are in line with current laboratory findings that examine response to paired physical and psychological stressors suggesting MCMAP may be a good real world analogue of laboratory based layered stress experiments. The higher intensity training sessions utilized in study two generated an enhanced proliferative response similar to that observed from exercise in competitive settings suggestive of a psychologically driven mechanism for proliferation.