Claim
mechanistic

When athletes overtrain, their stress hormone system can become worn out, so their body doesn't respond normally to stress and their daily hormone patterns get messed up.

Evidence from Studies

No evidence studies found yet.

What Would Prove This

Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.

1
Systematic Reviews & Meta-Analyses

Quantify the effect size and consistency of HPA axis blunting in OTS across studies.

A meta-analysis of 12+ studies using insulin tolerance test (ITT) and salivary cortisol rhythm (SCR) in athletes with clinically diagnosed OTS versus healthy controls, pooling data on ACTH and cortisol responses, with at least 300 participants.

2
Cohort Studies

Demonstrate that HPA axis changes precede the development of full OTS.

A 9-month prospective cohort study of 200 elite endurance athletes, measuring HPA axis function (ITT, SCR) quarterly, tracking training load, recovery, and performance, to identify endocrine predictors of OTS onset.

3
Cross-Sectional Studies

Compare HPA axis function between athletes with and without OTS at a single time point.

A cross-sectional study of 120 athletes (60 with OTS, 60 controls), assessing HPA axis via ITT and SCR, along with POMS, training history, and performance metrics.

4
Expert Opinion & Narrative Reviews
In Evidence

Integrate findings into a comprehensive model of neuroendocrine dysfunction in OTS.

A narrative review by endocrinology and sports medicine experts summarizing evidence on HPA axis alterations in overtrained athletes, discussing diagnostic and therapeutic implications.

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Does overtraining affect your stress hormones and cortisol levels? | Scientific Fact Check | Fit Body Science