title: Reliability of salivary cortisol and immunoglobulin-A measurements from the IPRO® before and after sprint cycling exercise.
abstract: BACKGROUND
  The purpose of this study was to evaluate the inter-day reliability of the IPRO method for determining resting and postexercise salivary cortisol (sCort) and rate of salivary Immunoglobulin-A (sIgA) secretion.
  
  
  METHODS
  Fourteen males (32±11 years) performed two trials (T1 and T2) separated by 7 d, comprising saliva sampling before and 15 min after completion of two, 30-s Wingate Anaerobic Tests separated by 3.5 min (2 x WAnT). sCort increased after the 2 x WAnT in both trials (T1: P<0.001; T2: P<0.001), whereas rate of sIgA secretion decreased in both trials (T1: P=0.002; T2: P=0.002).
  
  
  RESULTS
  The intraclass correlation coefficients for resting and postexercise sCort and rate of sIgA secretion ranged from 0.96-0.99. Mean reliability, expressed as the coefficient of variation (%) and the typical error of measurement over the two trials were resting sCort 9.4%, 0.14 ng·mL-1 (9% CI: 0.1-0.2), postexercise sCort 11.9%, 0.44 ng·mL-1 (9% CI: 0.3-0.7), resting rate of sIgA secretion 7.4%, 85.5 µg·mL-1·min-1 (9% CI: 65.2-127.1) and postexercise rate of sIgA secretion 10.5%, 82.9 µg·mL-1·min-1 (9% CI: 63.2-123.1).
  
  
  CONCLUSIONS
  The IPRO is a reliable method for determining sCort and rate of sIgA secretion at rest and after sprint-cycling exercise.
authors.affiliation: Griffith University Sports Science, School of Allied Health Sciences, Griffith University, Gold Coast, Australia - luke.macdonald@griffithuni.edu.au.|Centre of Excellence for Applied Sport Science Research, Queensland Academy of Sport, Department of National Parks, Sport and Racing, Level 1 Queensland Sport and Athletics Centre, Nathan, Australia - luke.macdonald@griffithuni.edu.au.
authors.forename: Luke A
authors.initials: LA
authors.lastname: Macdonald
authors.affiliation: Griffith University Sports Science, School of Allied Health Sciences, Griffith University, Gold Coast, Australia.
authors.forename: Phillip M
authors.initials: PM
authors.lastname: Bellinger
authors.affiliation: Griffith University Sports Science, School of Allied Health Sciences, Griffith University, Gold Coast, Australia.
authors.forename: Clare L
authors.initials: CL
authors.lastname: Minahan
mesh_terms: D000328:Adult; D001642:Bicycling; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis*; D007071:Immunoglobulin A, Secretory / Q000032:analysis*; D008297:Male; D015203:Reproducibility of Results; D012463:Saliva / Q000737:chemistry*; D055815:Young Adult
chemical_list: D007071:Immunoglobulin A, Secretory; D006854:Hydrocortisone