Research

Hormonal

Basal (resting) hormone measurements, including cortisol and testosterone/cortisol ratios, are not useful for diagnosing overtraining syndrome or distinguishing between well-adapted and overtrained athletes.

Do not rely on resting blood tests for testosterone or cortisol to diagnose overtraining. These levels are influenced by many factors and do not reliably distinguish between healthy adaptation and overtraining. Focus on performance metrics and subjective feelings of fatigue.

GoodRefutesHIGH confidence
Therefore, it can be concluded that resting cortisol is not a useful measurement... the current information regarding the endocrine system and OR/OTS shows that basal (resting) hormone measurements cannot distinguish between athletes who successfully adapt to OR and those who fail to adapt and develop symptoms of OTS.
Romain Meeusen et al. · Medicine & Science in Sports & Exercise · 2013

Why this rating

Consensus statement based on review of multiple studies showing inconsistent or non-diagnostic results.

Source

Prevention, Diagnosis, and Treatment of the Overtraining Syndrome

Romain Meeusen et al. · Medicine & Science in Sports & Exercise · 2013

DOI 10.1249/mss.0b013e318279a10a

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DOI resolved against Crossref · corpus check 2026-06-10

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