Table 1.

Clinical inclusion criteria for the EROS study

All participants	All athletes	OTS-affected athletes
1. Male sex, 18–50 y/o, 20–32.9 kg/m2 (athletes) and 20–29.9 kg/m2 (sedentary)	1. Weekly exercise at least four times and >300 min of moderate-to-vigorous training intensity	1. Underperformance of ≥10% of previous performance as verified by certified sports coach, or loss of ≥20% in time-to-fatigue, with self-reported increase in sense of effort in training relative to before OTS
2. No previous psychiatric disorders or use of centrally acting drugs	2. Continuous training for at least 6 months with no interruption of training for >30 days	2. Prolonged underperformance not explained by conditions that could lead to decrease in performance, such as infections, inflammation, actual primary hormonal dysfunctions, psychosocial or psychiatric conditions, or emotional and social problems
3. No hormonal therapy in the preceding 6 months		3. Persistent fatigue (>2 weeks), as a subjective feeling, further confirmed by the Profile of Mood Scales, and decreased sleep quality (self-reported, compared with previous sleep quality)

EROS, Endocrine and Metabolic Responses on Overtraining Syndrome; y/o, years old.