Out of 32 symptoms commonly attributed to low testosterone, only 3 actually correlate with it. All three are sexual. The other 29 — fatigue, brain fog, low mood, weight you can't lose, feeling not quite like yourself — are real, but they are produced by something else, and the wellness-clinic funnel runs on getting that wrong.

Episode 2 of our Signal book launch series. Dr. Jordan Feigenbaum and Dr. Austin Baraki cover how testosterone actually works, what the number on your lab report is really measuring, and what a real evaluation of low T looks like.

Pre-order our book, Signal: barbellmedicine.com/signal

Timestamps:

00:00 Mark, revisited (cold open)

02:00 How testosterone actually works (HPG axis)

06:14 Why "in range" can still be abnormal

09:24 What your lab number actually measures

12:25 Case: total 230, low SHBG — does this guy need TRT?

17:04 The saturation model — why higher isn't better

21:11 A patient at 480 wants 900: how the conversation goes

28:57 What "in range" actually means (and why 264 is the cutoff)

34:41 The 3 symptoms that matter (out of 32)

37:16 Walking back a 10-symptom checklist

42:31 How a real testosterone workup gets done

46:42 Chasland trial — TRT vs. exercise at low-normal T

49:31 A warning for hard-training men

58:48 Takeaways, tease, and what's coming next

What we cover:

The HPG axis explained — and why one low total testosterone reading tells you almost nothing about where the problem actually sits.

The difference between total, free, and bioavailable testosterone — and why SHBG, the binding protein the wellness-clinic workup almost always ignores, is what determines whether the number on your lab report is misleading you in either direction.

The saturation model: above roughly 250 ng/dL, the prostate androgen receptor is saturated. Libido follows the same plateau. Pushing a normal man from 500 to 900 isn't doing what the marketing implies.

The EMAS study finding: of 32 symptoms men commonly attribute to low testosterone, only 3 actually correlate. Every other symptom needs a different workup.

How a real testosterone workup gets done — morning sample, fasted, repeat draw, LH/FSH/SHBG to localize and contextualize.

The Chasland 2021 trial: when standard TRT is prescribed properly to middle-aged men with low-normal levels, does it beat exercise? The answer is what most of the wellness-clinic industry is built on getting wrong.

A note for hard-training men: the exercise-hypogonadal-male pattern, what "low-normal" means in someone whose levels are an adaptation to training load rather than a baseline deficit, and why a textbook TRT dose in that man may functionally act as a performance enhancer.

If you have a lab report on your kitchen counter right now, this is what we wrote for you. Signal, the book, drops in May. Pre-order available soon at barbellmedicine.com.

Resources & links

Signal — Feigenbaum & Baraki (Barbell Medicine, 2026): coming soon

Episode 1 (Is the Testosterone Crisis Real?): https://stream.redcircle.com/episodes/b25a8006-57e5-4dc3-b74c-203f6fbcebc1/stream.mp3

Training Plateau Action Plan (free): barbellmedicine.com/training-plateau-action-plan

Barbell Medicine programs and consultations: barbellmedicine.com

To support us and get ad free listening, plus special product discounts, and exclusive content, go to supercast.barbellmedicine.com

Referenced studies

Wu FCW et al. 2010 - Identification of late-onset hypogonadism in middle-aged and elderly men. NEJM 363(2):123-135. [The EMAS 3-of-32 finding]

https://pubmed.ncbi.nlm.nih.gov/20554979/

Bhasin S et al. 2018 - Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. JCEM 103(5):1715-1744. [264 ng/dL threshold; first-draw protocol]

https://pubmed.ncbi.nlm.nih.gov/29562364/

Travison TG et al. 2008 - The natural history of symptomatic androgen deficiency in men. JAGS 56(5):831-839. [MMAS: ~50% of initially low values normalize on repeat]

https://pubmed.ncbi.nlm.nih.gov/18308002/

Travison TG et al. 2006 - The relationship between libido and testosterone levels in aging men. JCEM 91(7):2509-2513. [Libido plateau data, Framingham + HIM]

https://pubmed.ncbi.nlm.nih.gov/16670164/

Brambilla DJ et al. 2009 - The effect of diurnal variation on clinical measurement of serum testosterone. JCEM 94(3):907-913. [Why morning, fasted matters]

https://pubmed.ncbi.nlm.nih.gov/19112025/

Morgentaler A & Traish AM. 2009 - Shifting the paradigm of testosterone and prostate cancer: the saturation model and the limits of androgen-dependent growth. Eur Urol 55(2):310-320. [The saturation model]

https://pubmed.ncbi.nlm.nih.gov/18838208/

Trost LW & Mulhall JP. 2016 - Challenges in Testosterone Measurement, Data Interpretation, and Methodological Appraisal of Interventional Trials. J Sex Med 13(7):1029-1046. [Free T unreliability at the low end; equilibrium dialysis as the reference method]

https://pubmed.ncbi.nlm.nih.gov/27210182/

Vermeulen A et al. 1999 - A critical evaluation of simple methods for the estimation of free testosterone in serum. JCEM 84(10):3666-3672. [Calculated free T methodology]

https://pubmed.ncbi.nlm.nih.gov/10523012/

Chasland LC et al. 2021 - Testosterone and exercise: effects on fitness, body composition, and strength in middle-to-older aged men with low-normal serum testosterone levels. Am J Physiol Heart Circ Physiol 320(5):H1985-H1998. [The 12-week trial]

https://pubmed.ncbi.nlm.nih.gov/33739153/

Arun AS et al. 2025 - Reevaluating the Threshold for Low Total Testosterone. Clin Chem 71(5):609-611. [2025 NHANES strength-dissociation reference]

https://pubmed.ncbi.nlm.nih.gov/40066943/

Baillargeon J et al. 2015 - Trends in Androgen Prescribing in the United States, 2001-2011. JAMA Intern Med 175(8):1413-1415. [25% no preceding lab; the 50% no follow-up monitoring gap - referenced from Episode 1]

https://pubmed.ncbi.nlm.nih.gov/26075486/

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