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Overtraining Syndrome Biomarkers

Meaning

Measurable biochemical, hormonal, or physiological indicators found in blood, saliva, or other bodily fluids that collectively suggest the presence of Overtraining Syndrome (OTS), a state of prolonged underperformance and maladaptation to exercise training. Key hormonal biomarkers often include an altered cortisol-to-testosterone ratio, suppressed free thyroxine (fT4) and triiodothyronine (T3) levels, and dysregulated heart rate variability. These markers help distinguish functional overreaching from true pathological overtraining.