title: Recovery of endocrine and inflammatory mediators following an extended energy deficit.
abstract: BACKGROUND
  Due to current operational requirements, elite soldiers deploy quickly after completing arduous training courses. Therefore, it is imperative that endocrine and inflammatory mediators have fully recovered.
  
  
  OBJECTIVE
  Our objective was to determine whether a short-term (2-6 wk) recovery period was sufficient to restore endocrine and inflammatory homeostasis after sustained energy deficit.
  
  
  METHODS
  Before and immediately after the course, serum concentrations of inflammatory and endocrine markers were taken along with anthropometric measures prior to and immediately after the Army Ranger course. In addition, nine soldiers were assessed between 2 and 6 weeks after the course.
  
  
  METHODS
  This research occurred in a field setting during an intensive 8-week military training course characterized by high-energy expenditure, energy restriction, and sleep deprivation (U.S. Army Ranger School).
  
  
  METHODS
  Twenty-three male soldiers (23.0 ± 2.8 y; 177.6 ± 7.9 cm; 81.0 ± 9.6 kg, 16.8 ± 3.9% body fat) participated in this study.
  
  
  METHODS
  There were no interventions used in this research.
  
  
  RESULTS
  Significant changes occurred in circulating total testosterone (-70%), brain-derived neurotrophic factor (-33%), total IGF-1 (-38.7%), free IGF-1 (-41%), IGF binding protein (IGFBP-6; -23.4%), sex-hormone binding globulin (+46%), thyroid stimulating hormone (+85%), IGFBP-1 (+534.4%), IGFBP-2 (+98.3%), IGFBP-3 (+14.7%), IL-4 (+135%), IL-6 (+217%), and IL-8 (+101%). Significant changes in body mass (-8%), bicep (-14%), forearm (-5%), thigh (-7%), and calf (-2%) circumferences, sum of skinfolds (-52%), and percentage body fat (-54%). All anthropometric, inflammatory, and hormonal values, except T3, were restored to baseline levels within 2-6 weeks after the course.
  
  
  CONCLUSIONS
  Endocrine markers and anthropometric measures were degraded, and inflammatory mediators increased after an extended energy deficit. A short-term recovery of 2-6 weeks was sufficient to restore these mediators.
authors.affiliation: Military Performance Division (P.C.H., D.E.S., B.A.S., J.S.S., R.W.M., B.C.N.), U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts 01760; Madigan Healthcare System (M.A.S.), Joint Base Lewis-McChord, Washington 98431; and Sections of Endocrinology (S.B.), Diabetes, and Nutrition, Boston University School of Medicine, Boston University, Boston, Massachusetts 02118; and Army Institute of Public Health Army Public Health Command (B.C.N.), Aberdeen Proving Ground, Maryland 21010.
authors.forename: Paul C
authors.initials: PC
authors.lastname: Henning
authors.forename: Dennis E
authors.initials: DE
authors.lastname: Scofield
authors.forename: Barry A
authors.initials: BA
authors.lastname: Spiering
authors.forename: Jeffery S
authors.initials: JS
authors.lastname: Staab
authors.forename: Ronald W
authors.initials: RW
authors.lastname: Matheny
authors.forename: Martha A
authors.initials: MA
authors.lastname: Smith
authors.forename: Shalender
authors.initials: S
authors.lastname: Bhasin
authors.forename: Bradley C
authors.initials: BC
authors.lastname: Nindl
mesh_terms: D000328:Adult; D031204:Caloric Restriction; D016207:Cytokines / Q000097:blood; D004734:Energy Metabolism; D005508:Food Deprivation; D006728:Hormones / Q000097:blood*; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood*; D008297:Male; D008889:Military Personnel; D020127:Recovery of Function; D012892:Sleep Deprivation / Q000097:blood / Q000534:rehabilitation; D013217:Starvation / Q000097:blood / Q000534:rehabilitation; D055815:Young Adult
chemical_list: D016207:Cytokines; D006728:Hormones; D018836:Inflammation Mediators