title: Carbohydrate supplementation does not blunt the prolonged exercise-induced reduction of in vivo immunity.
abstract: BACKGROUND
  Carbohydrate (CHO) supplementation during prolonged exercise is widely acknowledged to blunt in vitro immunoendocrine responses, but no study has investigated in vivo immunity.
  
  
  OBJECTIVE
  To determine the effect of CHO supplementation during prolonged exercise on in vivo immune induction using experimental contact hypersensitivity with the novel antigen diphenylcyclopropenone (DPCP).
  
  
  METHODS
  In a double-blind design, 32 subjects were randomly assigned to 120 min of treadmill exercise at 60 % [Formula: see text] with CHO (Ex-CHO) or placebo (Ex-PLA) supplementation. Responses were also compared to 16 resting control (CON) subjects from a previous study (for additional comparison with a resting non-exercise condition). Standardised diets (24 h pre-trial) and breakfasts (3.5 h pre-trial) were provided. Subjects received a primary DPCP exposure (sensitisation) 20 min after trial completion, and exactly 28 days later the strength of immune reactivity was quantified by magnitude of the cutaneous response (skin-fold thickness and erythema) to a low dose-series DPCP challenge. Stress hormones and leucocyte trafficking were also monitored.
  
  
  RESULTS
  CHO supplementation blunted the cortisol and leucocyte trafficking responses, but there was no difference (P > 0.05) between Ex-CHO and Ex-PLA in the in vivo immune responses (e.g. both ~46 % lower than CON for skin-fold response).
  
  
  CONCLUSIONS
  CHO supplementation does not influence the decrease in in vivo immunity seen after prolonged exercise. The effects with more stressful (or fasted) exercise remain to be determined. However, there appears to be no benefit under the conditions of the present study, which have practical relevance to what many athletes do in training or competition.
authors.affiliation: Endurance Research Group, School of Sport and Exercise Sciences, University of Kent, The Medway Campus, Kent, ME4 4AG, UK. G.Davison@kent.ac.uk.
authors.forename: Glen
authors.initials: G
authors.lastname: Davison
authors.affiliation: Endurance Research Group, School of Sport and Exercise Sciences, University of Kent, The Medway Campus, Kent, ME4 4AG, UK.
authors.forename: Corinna
authors.initials: C
authors.lastname: Kehaya
authors.affiliation: Extremes Research Group, College of Health and Behavioural Sciences, Bangor University, Bangor, UK.
authors.forename: Bethany C
authors.initials: BC
authors.lastname: Diment
authors.affiliation: Extremes Research Group, College of Health and Behavioural Sciences, Bangor University, Bangor, UK.
authors.forename: Neil P
authors.initials: NP
authors.lastname: Walsh
mesh_terms: D000328:Adult; D003521:Cyclopropanes / Q000276:immunology; D004032:Diet; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D019587:Dietary Supplements; D004311:Double-Blind Method; D004890:Erythema / Q000097:blood / Q000276:immunology; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D006967:Hypersensitivity / Q000097:blood / Q000276:immunology; D007108:Immune Tolerance; D007958:Leukocyte Count; D007962:Leukocytes / Q000276:immunology; D008297:Male; D010101:Oxygen Consumption; D012146:Rest; D055815:Young Adult
chemical_list: D003521:Cyclopropanes; D004040:Dietary Carbohydrates; C029402:diphenylcyclopropenone; D006854:Hydrocortisone
keywords: Contact hypersensitivity; Diphenylcyclopropenone; Glucose; Immune; Running; Whole integrated immune response