Fig. 1

Circulating levels of inflammatory mediators according to self-perceived fatigue and muscle endurance. Bars represent mean ± standard error. Inflammatory markers are expressed as log(10) transformed values. Since all log(10) transformed values For IFN-γ were negative (IFN-γ concentrations were >1) all data were summed by 1 in order to optimise the visual interpretation of figure 1E. ANCOVA analysis (with weekly physical activity, percentage body fat and presence of inflammatory conditions as covariates) revealed significant differences between the subgroups for A hs-CRP (p<0.001), B IL-6 (p<0.001), C TNF-alpha (p=0.028), D IL-10 (p=0.035) and E IFN-γ (p=0.015). Overall, participants with high self-perceived fatigue and low muscle endurance presented the highest (except for IFN-γ, figure 1E) and those with normal self-perceived fatigue and normal muscle endurance the lowest levels of inflammatory mediators. F Post-hoc pairwise comparisons showed that participants with high self-perceived fatigue and low muscle endurance presented significantly higher hs-CRP and IL-6 levels compared to those with normal self-perceived fatigue and normal muscle endurance (p<0.01), as well as lower hs-CRP compared to those with normal self-perceived fatigue but low muscle endurance (p<0.01). Participants with normal self-perceived fatigue and normal muscle endurance showed also significantly lower levels of IL-6 compared to those with normal self-perceived fatigue and low muscle endurance (p<0.05), and lower hs-CRP, IL-6 and IFN-γ compared to participants with high self-perceived fatigue and normal muscle endurance (respectivelyp<0.05, p<0.01 and p<0.01)