title: Cognitive awareness of carbohydrate intake does not alter exercise-induced lymphocyte apoptosis.
abstract: OBJECTIVE
  The purpose of this investigation was to determine whether cognitive awareness of carbohydrate beverage consumption affects exercise-induced lymphocyte apoptosis, independent of actual carbohydrate intake.
  
  
  BACKGROUND
  Carbohydrate supplementation during aerobic exercise generally protects against the immunosuppressive effects of exercise. It is not currently known whether carbohydrate consumption or simply the knowledge of carbohydrate consumption also has that effect.
  
  
  METHODS
  Endurance trained male and female (N = 10) athletes were randomly assigned to one of two groups based on either a correct or incorrect cognitive awareness of carbohydrate intake. In the incorrect group, the subjects were informed that they were receiving the carbohydrate beverage but actually received the placebo beverage. Participants completed a 60-min ride on a cycle ergometer at 80% VO₂peak under carbohydrate and placebo supplemented conditions. Venous blood samples were collected at rest and immediately after exercise and were used to determine the plasma glucose concentration, lymphocyte count, and extent of lymphocyte apoptosis. Cognitive awareness, either correct or incorrect, did not have an effect on any of the measured variables.
  
  
  RESULTS
  Carbohydrate supplementation during exercise did not have an effect on lymphocyte count or apoptotic index. Independent of drink type, exercise resulted in significant lymphocytosis and lymphocyte apoptosis (apoptotic index at rest = 6.3 ± 3% and apoptotic index following exercise = 11.6 ± 3%, P < 0.01).
  
  
  CONCLUSIONS
  Neither carbohydrate nor placebo supplementation altered the typical lymphocyte apoptotic response following exercise. While carbohydrate supplementation generally has an immune-boosting effect during exercise, it appears that this influence does not extend to the mechanisms that govern exercise-induced lymphocyte cell death.
authors.affiliation: Western Kentucky University - Kinesiology, Recreation, and Sport, Bowling Green, Kentucky, USA. james.navalta@wku.edu
authors.forename: James Wilfred
authors.initials: JW
authors.lastname: Navalta
authors.forename: Brian Keith
authors.initials: BK
authors.lastname: McFarlin
authors.forename: Scott
authors.initials: S
authors.lastname: Lyons
authors.forename: Scott Wesley
authors.initials: SW
authors.lastname: Arnett
authors.forename: Mark Anthony
authors.initials: MA
authors.lastname: Schafer
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D017209:Apoptosis / Q000502:physiology; D001364:Awareness / Q000502:physiology*; D001628:Beverages; D001786:Blood Glucose / Q000032:analysis; D003071:Cognition / Q000502:physiology; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000502:physiology; D008297:Male; D010807:Physical Endurance / Q000276:immunology*; D018709:Statistics, Nonparametric; D013312:Stress, Physiological / Q000276:immunology
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates