Purpose/Hypothesis:

Marathon running requires multiple hours of exertion that can result in significant changes in inflammatory markers even days after the competition. We investigated how running a marathon affects inflammatory cytokines before, immediately after, and 48 hours post-race. We hypothesize that inflammatory cytokines will increase post-race and return to baseline after 48 hours.

Methodology:  

Blood samples were collected from 24 Ogden Marathon runners at three time points: pre, post, and 48 hours after the race. Plasma levels of TNF-a, IFY, IL-4, IL-10, IL-6, and IL-1B were measured using Luminex® MAGPIX® multiplex assays, with differences analyzed using repeated measures ANOVA.

Results:  

IL-6 levels increased significantly from pre to post (3.1 ± 1.2 vs 70.8 ± 18.1, p= .002) but returned to baseline after 48 hours (3.1 ± 1.2 vs 2.4 ± 0.1, p=.22). IL-10 levels also rose post-race (21.5 ± 7.1 vs 98.8 ± 21.4, p= .001) but fell below baseline at 48 hours (21.5 ± 7.1 vs 14.1 ± 4.8, p=.035). No significant change was observed in TNFα pre to post (25.8 ± 4.9 vs 27.6 ± 4.6, p= .74), but a significant decrease was noted at 48 hours (27.6 ± 4.6 vs 17 ± 3, p=.046).

Discussion/Conclusion:

Muscle contraction results in the secretion of cytokines IL-10, IL-6, and TNFα which were expected to increase after running a marathon. IL-10 has potent anti-inflammatory and pro-resolving properties; the return to below baseline levels observed after 48 hours is likely due to finalizing the resolution process of inflammation. IL-6 induces the secretion of anti-inflammatory cytokines, induces glucose production, and triggers fatty acid oxidation, which is a process favored during long-distance running.