Inflammatory Biomarkers in Elite Cross-Country Skiers After a Competition Season: A Case–Control Study

Abstract

Purpose Whether elite athletes, who have been exposed to vigorous-intensity exercise combined with other stressors, have elevated systemic low-grade inflammation, remains largely unclear. To address this question, we studied the levels of six inflammatory cytokines as potential biomarkers of a low-grade inflammatory state in elite athletes after an 11-month training and competition season. Methods We collected sera from 27 Finnish elite cross-country skiers and 27 gender- and age-matched, moderately-exercising controls. The serum concentrations of C-reactive protein (CRP), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), glycoprotein acetyls (GlycA), interleukin 10 (IL-10), and interferon gamma (IFN-γ) cytokines were quantified as surrogate markers of low-grade inflammation. Results The athletes were found to have significantly lower concentrations of CRP (P = 0.0232) and higher concentrations of IL-10, TNF-α, and IFN-γ (P = 0.0097, P = 0.0256, and P = 0.0185, respectively) than the controls. No significant differences between athletes and controls were detected in the concentrations of IL-6 and GlycA. The inflammatory score (IS) did not differ significantly between athletes and controls. Conclusion The results of this study argued against the hypothesis of a significant chronic low-grade inflammation in response to prolonged high-performance exercise among elite endurance athletes.

Proteomic and Metabolomic Analyses of the Blood Samples of Highly Trained Athletes

“…Protein metabolism (synthesis/degradation) is a continuous process that is intensified during and after training and is characterized by the changing rate of amino acid release and elimination from the bloodstream [13]. During regular long-term training loads, protein metabolism acts as an additional source of energy [14], ensures organism recovery after muscle injuries (aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, gamma-glutamyl transferase, creatine kinase, and myoglobin) [15,16] and inflammation (C-reactive protein, interleukins IL-6 and IL-1β, tumor necrosis factor-α) [17], ensures the endocrine response (cortisol and testosterone) [18,19], as well as regulates the immune response [20,21] and the oxidative status [22,23].…”

Effect of 2 weeks rest-pause on oxidative stress and inflammation in female basketball players

“…Results published so far have shown that during training periods with the highest loads, muscle contractions increase the stimulation of ROS production in muscle fibers, contributing to the intensification of oxidative stress and in consequence an increase in oxidative damage (e.g., lipid peroxidation and increased protein oxidation). These negative changes may result in disorders in the functioning of the immune system, and increased muscle damage, leading to fatigue or overtraining 9 , 13 . The presented study aimed to assess whether a two-week period with a low training load is sufficient for full regeneration of female athletes, which may lead to increased adaptation processes.…”

“…It is known that an optimal balance between training load and recovery is required to improve exercise performance 9 , 10 . Long-term imbalance can lead to fatigue, overload, and overtraining where, especially in overtraining, pro-antioxidant imbalance becomes a fixed pattern, leading to a dramatic decrease in the condition and deterioration of the athlete's health 11 .…”

Cross‐sectional associations between physical fitness and biomarkers of inflammation in children—ThePANICstudy

“…10 The amount of muscle and fat mass and the level of physical activity differently influence the performance in different physical fitness tests, potentially altering the associations of physical fitness with biomarkers of inflammation. [23][24][25] However, the evidence on the associations of different measures of physical fitness and biomarkers of inflammation is scarce and elusive, leaving a significant knowledge gap.…”

“…Performance in the 40‐meter agility shuttle run test, a measure of neuromuscular fitness, has also been inversely associated with serum IL‐6, leptin, and adiponectin but not to hs‐CRP and TNF‐α 10 . The amount of muscle and fat mass and the level of physical activity differently influence the performance in different physical fitness tests, potentially altering the associations of physical fitness with biomarkers of inflammation 23–25 . However, the evidence on the associations of different measures of physical fitness and biomarkers of inflammation is scarce and elusive, leaving a significant knowledge gap.…”