title: Plasma Cytokine Profiles in Long-Term Strenuous Exercise.
abstract: The open window theory indicates altered immunity 3 to 72 hours after exercise. The J-curve describes the risk of illness in response to exercise. The aim of this study was to examine the secretion of proinflammatory and anti-inflammatory cytokines before and after long-term strenuous exercise. Fourteen marathon and 16 half-marathon runners and 10 military cadets participating in a military ranger-training course were recruited to this study. Within-subject design was used measuring levels of plasma cytokines before, during, and after exercise. Plasma cytokines were measured using Luminex multiplex technology and ELISA. Comparing pre/post plasma levels both the marathon- and the half-marathon runners showed heavily increased levels of IL-6, IL-10, and IL-8 (P < 0.001). LPS stimulation among the half-marathon runners decreased the postrace levels of IL-6, IL-1b, and TNFα by 45%, 24%, and 43%, respectively (P < 0.01). During the ranger training course the spontaneous and LPS-stimulated levels of IL-6, IL-8, IL-10, IL-1b, and TNFα changed in a similar fashion as in the half-marathon runners although the fluctuations were smaller. Our study supports the open window and the J-curve theory; the immune system is more activated and the subjects are more threatened to infectious pathogens after intensive physical activity and in the period after exercise.
authors.affiliation: Division for Society and Health, Department of Health, The Research Council of Norway, P.O. Box 564, 1327 Lysaker, Norway.
authors.forename: Hilde G
authors.initials: HG
authors.lastname: Nielsen
authors.affiliation: Department of Infectious Medicine, Oslo University Hospital, Ullevål, 0407 Oslo, Norway.
authors.forename: Olav
authors.initials: O
authors.lastname: Øktedalen
authors.affiliation: Norwegian Research Defence Establishment, P.O. Box 25, 2027 Kjeller, Norway; Norwegian Military Academy, 0593 Oslo, Norway.
authors.forename: Per-Kristian
authors.initials: PK
authors.lastname: Opstad
authors.affiliation: Department of Medical Biochemistry, Oslo University Hospital, Ullevål, P.O. Box 4956, Nydalen, 0424 Oslo, Norway.
authors.forename: Torstein
authors.initials: T
authors.lastname: Lyberg