Lim, Chin LeongPyne, DavidHorn, PeggyKalz, AmeliaSaunders, Philo UPeake, JonathanSuzuki, KatsuhikoWilson, GaryMackinnon, Laurel2015-12-081715-5312http://hdl.handle.net/1885/34712The effects of increased training (IT) load on plasma concentrations of lipopolysaccharides (LPS), proinflammatory cytokines, and anti-LPS antibodies during exercise in the heat were investigated in 18 male runners, who performed 14 days of normal training (NT) or 14 days of 20% IT load in 2 equal groups. Before (trial 1) and after (trial 2) the training intervention, all subjects ran at 70% maximum oxygen uptake on a treadmill under hot (35 °C) and humid (*40%) conditions, until core temperature reached 39.5 °C or volitional exhaustion. Venous blood samples were drawn before, after, and 1.5 h after exercise. Plasma LPS concentration after exercise increased by 71% (trial 1, p < 0.05) and 21% (trial 2) in the NT group and by 92% (trial 1, p < 0.01) and 199% (trial 2, p < 0.01) in the IT group. Postintervention plasma LPS concentration was 35% lower before exercise (p < 0.05) and 47% lower during recovery (p < 0.01) in the IT than in the NT group. Anti-LPS IgM concentration during recovery was 35% lower in the IT than in the NT group (p < 0.05). Plasma interleukin (IL)-6 and tumor necrosis factor (TNF)-α concentrations after exercise (IL-6, 3-7 times, p < 0.01, and TNF-α, 33%, p < 0.01) and during recovery (IL-6, 2-4 times, p < 0.05, and TNF-α, 30%, p < 0.01) were higher than at rest within each group. These data suggest that a short-term tolerable increase in training load may protect against developing endotoxemia during exercise in the heat.Keywords: autacoid; bacterium antibody; biological marker; cytokine; IL6 protein, human; interleukin 6; lipopolysaccharide; tumor necrosis factor alpha; article; blood; clinical trial; controlled clinical trial; controlled study; endotoxemia; endurance; heart rate; Anti-LPS antibodies; Cytokines; Endotoxemia; Heat tolerance; Lipopolysaccharides200910.1139/H09-0212016-02-24