title: Immune responses to strenuous exercise and carbohydrate intake in boys and men.
abstract: Few studies describe immune responses to exercise in children, compared with adults, and none have investigated the influence of carbohydrate (CHO) intake. We hypothesized less perturbation and a faster recovery of the immune system with exercise in children, regardless of supplemental energy. Twelve boys (9.8 +/- 0.1 y) and 10 men (22.1 +/- 0.5 y) cycled for 60 min at 70% o(2max) while drinking 6% CHO (CHO-T) or flavored water (FW-T). Blood samples were collected before (PRE), immediately after (POST), and 60 min after (REC) exercise. Boys, compared with men, had smaller (p < 0.05) increases in total leukocytes (28% versus 38%), natural killer (NK) cells (78% versus 236%), and NK T cells (42% versus 128%) at POST, averaged across beverage trials. Exercise did not increase tumor necrosis factor-alpha (TNF-alpha), but significantly (p < 0.05) increased IL-6 in men (189%), but not in boys (11%). In both trials, lymphocytes and T cells at REC were suppressed (p < 0.05), relative to PRE, in men (-21%), but not in boys (4%). IL-6 remained elevated ( p< 0.001) in men at REC, with no change from POST in boys. In boys, but not in men, CHO significantly (p < 0.05) attenuated increases in neutrophil, lymphocyte, and NK cell counts at POST. Neutrophils at REC in CHO-T were lower (p < 0.05) than in FW-T in men ( approximately 25%) and in boys ( approximately 17%). CHO had no effect on TNF-alpha or IL-6 in either group. Our results indicate a distinct pattern of the immune response to exercise and CHO intake in boys, compared with men.
authors.affiliation: Children's Exercise and Nutrition Centre, Chedoke Hospital, Evel Bldg. (4 floor), Sanatorium Road, Hamilton, Ontario, Canada L8N 3Z5.
authors.forename: Brian W
authors.initials: BW
authors.lastname: Timmons
authors.forename: Mark A
authors.initials: MA
authors.lastname: Tarnopolsky
authors.forename: Oded
authors.initials: O
authors.lastname: Bar-Or
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D002648:Child; D004040:Dietary Carbohydrates / Q000378:metabolism*; D015444:Exercise; D006801:Humans; D007107:Immune System / Q000502:physiology*; D015850:Interleukin-6 / Q000378:metabolism; D016131:Lymphocyte Subsets / Q000276:immunology; D008297:Male; D013601:T-Lymphocytes / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha