title: Immune responses and increased training of the elite athlete.
abstract: Ten elite male runners (age, 29.8 +/- 1.7 yr; maximum oxygen consumption, 65.3 +/- 4.9 ml.kg-1.min-1; 10-km times, 31 min 43 s +/- 1 min 46 s) deliberately increased training schedules by an average of 38% for 3 wk. Resting heart rate and maximal oxygen intake were unchanged, but the heart rate response to acute exercise was decreased. Following heavy training, blood samples taken at rest showed trends to a decreased helper/suppressor cell ratio, an increased phytohemagglutinin (PHA)- and concanavalin (ConA)-stimulated lymphocyte proliferation, and a decreased production of immunoglobulins IgG and IgM. Whereas PHA-stimulated lymphocyte proliferation was initially unchanged by acute exercise, after 3 wk of heavy training the same acute exercise caused an 18% suppression of proliferation. Acute exercise following heavy training did not alter pokeweed-stimulated IgG or IgM synthesis. There was no correlation between changes in lymphocyte subpopulations, helper/suppressor ratios, and mitogen-induced cellular proliferation. The immune system of endurance-trained athletes at rest seemed to tolerate the stress of heavy training, but superimposition of a bout of acute exercise on the chronic stress of heavy training resulted in immunosuppression, which was transient and most likely not of clinical significance.
authors.affiliation: Department of Community Health, Faculty of Medicine, University of Toronto, Ontario, Canada.
authors.forename: T J
authors.initials: TJ
authors.lastname: Verde
authors.forename: S G
authors.initials: SG
authors.lastname: Thomas
authors.forename: R W
authors.initials: RW
authors.lastname: Moore
authors.forename: P
authors.initials: P
authors.lastname: Shek
authors.forename: R J
authors.initials: RJ
authors.lastname: Shephard
mesh_terms: D000328:Adult; D000917:Antibody Formation / Q000502:physiology; D015444:Exercise / Q000502:physiology; D006801:Humans; D007109:Immunity / Q000502:physiology*; D007111:Immunity, Cellular / Q000187:drug effects; D007136:Immunoglobulins / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D010806:Physical Education and Training; D011043:Pokeweed Mitogens / Q000494:pharmacology; D012420:Running
chemical_list: D007136:Immunoglobulins; D011043:Pokeweed Mitogens