Overtraining Syndrome: Causes, Diagnosis, and What's Actually Going On

In 2022, researchers conducted the most rigorous systematic review ever performed on overtraining syndrome — looking specifically for controlled studies that documented a human transitioning from a healthy training state to an overtrained state. Zero studies met those criteria.

The word "overtrained" appears in coaching certifications, wearable device dashboards, and clinical sports medicine guidelines — and in each context it means something different. That definitional chaos has consequences: it delays real diagnoses, produces nocebo effects with measurable physiological outcomes, and leads athletes to reduce training they didn't need to reduce.

In this episode, Drs. Jordan Feigenbaum and Austin Baraki work through the full evidence base on overtraining syndrome — the taxonomy, the attempted studies, the six competing mechanistic theories, the biomarker failures, and what's actually happening when a lifter can't make progress.

Timestamps:

• 0:00 Cold open — the zero-studies finding
• 1:21 Why "overtrained" does four different jobs simultaneously
• 16:10 The FOR / NFOR / OTS taxonomy
• 19:43 The supercompensation model — borrowed from endurance, never validated for resistance training
• 32:28 Austin's clinical differential for fatigue and declining performance
• 36:17 RT evidence — what happens when researchers try to induce OTS through lifting
• 43:19 Austin — what actually drives the complaints he sees in practice
• 47:30 Six theories for what causes overtraining syndrome
• 1:01:09 The biomarker problem — why the T:C ratio and cortisol don't work
• 1:05:09 What your wearable is actually measuring (and what it isn't)
• 1:09:28 Austin — testosterone levels in trained athletes and when to act
• 1:13:40 Heart rate variability — limitations for strength training
• 1:15:36 Session RPE — the monitoring tool that actually works
• 1:17:31 How common is overtraining syndrome, really?
• 1:23:04 Three failure modes — what's actually happening when lifters say they feel overtrained
• 1:32:14 Austin — what a proper medical workup looks like
• 1:34:22 Outro

What we cover:

• The definition problem — why a single word is doing four incompatible jobs simultaneously, and why that matters clinically and practically.
• The taxonomy — functional overreaching, nonfunctional overreaching, and overtraining syndrome as points on a continuous variable that can only be identified after the fact, not at presentation.
• The supercompensation model — where it came from, why it fails to describe how resistance training adaptation actually works, and how applying it too literally produces both overloading and underloading errors at the same time.
• Austin's clinical differential — what a physician actually works through when a patient presents with fatigue and declining performance, and where overtraining syndrome actually sits on that list.
• What resistance training research shows — including 140 maximal singles, 90 working sets per week, and daily 1-rep max attempts. No study has cleanly induced overtraining syndrome through resistance training. The hormonal data went in the opposite direction from what the endurance overtraining model predicts.
• Six mechanistic theories — glycogen depletion, serotonin/BCAA, autonomic imbalance, central governor, HPA axis dysregulation, and Armstrong's complex systems framework. Each one is partially supported and each falls short.
• The biomarker problem — resting cortisol is normal in 75%+ of OTS cases, the testosterone to cortisol ratio has never been validated against clinical outcomes as an individual diagnostic, and HRV recovery in strength training lags physical recovery by up to 30 hours.
• Austin on wearables — including a clinical pattern he's seeing with GLP-1 receptor agonists: wearable scores indicating deterioration when the clinical picture is actually fine.
• Session RPE as the real tool — why session RPE trending upward at stable training load is a more reliable signal of load-recovery mismatch than any biomarker currently used.
• Prevalence and confounders — the 60% figure, why it almost certainly captures all three FOR/NFOR/OTS categories plus REDS, depression, and illness, and why the residual true training-load-induced OTS in an otherwise healthy athlete may be vanishingly rare.
• Three failure modes — the three things Jordan actually sees in practice when lifters present saying they feel overtrained, and how to distinguish between them using session RPE.
• The medical workup — Austin's practical walkthrough of what to assess when programming and lifestyle changes don't move the needle, including iron deficiency (ferritin testing caveats, lab reference range problems), sleep apnea, post-viral syndromes, and hormone panels done correctly.

Next Steps:

For evidence-based resistance training programs: barbellmedicine.com/training-programs

For individualized training consultation: barbellmedicine.com/coaching

Explore our full library of articles on health and performance: barbellmedicine.com/resources

To consult with Drs. Baraki or Feigenbaum email us at [email protected]

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Resources

Taxonomy / Definitions

Meeusen et al. (2013)

European College of Sport Science / ACSM consensus statement on FOR, NFOR, and OTS taxonomy. Defines OTS as a diagnosis of exclusion.

https://pubmed.ncbi.nlm.nih.gov/23247672/

Meeusen et al. (2006)

"Often only after a period of complete rest" — the retrospective nature of distinguishing NFOR from OTS.

https://pubmed.ncbi.nlm.nih.gov/23016079/

Nocebo Effects in Sport

2024 Systematic Review

Nocebo effects in sport were approximately twice the magnitude of placebo effects on performance across 20 studies.

https://pubmed.ncbi.nlm.nih.gov/38999724/

Stress-Recovery-Adaptation Model

Original general adaptation syndrome / stress physiology work in Nature. Foundational source the SRA model was derived from — not a sports science paper.

https://www.nature.com/articles/138032a0

Multi-system adaptation timescales; critique of single-wave supercompensation model.

https://pubmed.ncbi.nlm.nih.gov/3057313/

Multi-system adaptation timescales; further critique of the SRA "window of opportunity" model.

https://pubmed.ncbi.nlm.nih.gov/15044685/

Lack of empirical support for the supercompensation "window of opportunity" in real training scenarios.

https://pubmed.ncbi.nlm.nih.gov/29189930/

Resistance Training and OTS

Grandou et al. (2020)

Systematic review: 22 studies on resistance training overtr