The Endocrinology of Strongman: Hormones That Influence Mass, Strength and Recovery - Episode 2: Testosterone - What It Does and What It Doesn't Do

Episode 2: Testosterone - What It Does and What It Doesn't Do

After following the architecture of the hypothalamic-pituitary-gonadal axis in the previous episode, we now move to one of the hormones most discussed in strength sports: testosterone. In Strongman, testosterone is often presented either as the ultimate engine of strength or as a laboratory number that should simply be pushed as high as possible. Both pictures are too simple.

Testosterone is indeed a major androgen and has important effects on muscle mass, bone, erythropoiesis, libido, and reproductive function. At the same time, adaptation to strength training depends on many systems working together: the nervous system, muscle, tendons, bone, energy intake, sleep, stress, and training programming. Testosterone is an important piece of the engine, not the entire engine.

1. What is testosterone?

Testosterone is a steroid hormone in the androgen family. In men, most testosterone is produced in the testes, in Leydig cells, under the control of pituitary LH from the HPG axis. In women, there is ovarian and adrenal androgen production, while circulating testosterone comes from a combination of direct production and peripheral conversion.

In the blood, testosterone circulates bound to proteins, especially SHBG and albumin, plus a free fraction. Measuring total testosterone alone does not always capture the full biological picture, which is why clinical context and, in some situations, free or calculated free testosterone become relevant.

2. The first thing it does: signal through the androgen receptor

Testosterone exerts many of its effects through the androgen receptor, an intracellular protein that alters gene expression after activation. This means that hormonal action depends not only on the concentration in blood, but also on the receptor, the tissue, and local androgen conversion.

In some tissues, testosterone can be converted to dihydrotestosterone, DHT, by 5-alpha-reductase. In others, it can be aromatized to estradiol. Testosterone is therefore better understood as the central signal and precursor within a steroid network than as one molecule with one single effect.

3. What does testosterone do for muscle mass?

Testosterone contributes to the maintenance and development of muscle mass by influencing protein synthesis, muscle protein balance, and cellular processes that support adaptation. In androgen deficiency, lean mass and strength can decline.

But this is where the first major trap appears: the fact that testosterone is necessary and anabolic does not mean that every small, temporary rise in testosterone after training automatically produces more hypertrophy. Training studies have shown that muscle growth can occur without a chronic rise in basal testosterone and without acute hormonal peaks usefully predicting hypertrophy.

4. What does testosterone do for strength?

Testosterone supports a number of biological conditions that favor force production: maintenance of muscle mass, neuromuscular function, and the integrity of relevant tissues. When androgen deficiency is severe, performance can be impaired.

However, an acute testosterone increase is not an instant injection of strength. You can have a transient rise in testosterone after a hard workout without your 1RM increasing in the next hour. Maximal strength emerges from muscle mass, motor-unit recruitment, intermuscular coordination, technique, the stiffness of the musculoskeletal system, and adaptation to load.

5. What does testosterone do for bone?

Testosterone contributes to bone health through both androgenic effects and conversion of some testosterone to estradiol. In sports involving heavy loads, skeletal health matters enormously because bone is the infrastructure through which forces are transmitted.

For that reason, problematic androgen status should not be viewed only through the lens of muscle mass. An athlete can chase more kilos on the bar while ignoring a hormonal and energetic environment that, over time, no longer supports skeletal health.

6. Erythropoiesis: the effect that gets discussed less

Testosterone stimulates red blood cell production and can increase hemoglobin and hematocrit. This has relevance for oxygen transport, but it should not be turned into a single explanation for Strongman performance.

More is not automatically better. Excessive rises in hematocrit can become a clinical problem and are one reason testosterone therapy requires medical monitoring. Strongman performance, moreover, is not limited to oxygen transport.

7. Testosterone and libido

Testosterone has an important role in sexual function, but libido is not a simple laboratory marker. Sexual desire is also influenced by sleep, stress, relationships, mental health, medications, and other endocrine systems.

Therefore, low libido does not by itself prove testosterone deficiency, and high sexual desire does not prove an "optimal" hormone level.

8. Testosterone and recovery: the true part and the exaggerated part

A normal androgenic environment contributes to maintaining tissues and physiological functions required for adaptation. In androgen deficiency, recovery and body composition can be affected. Testosterone nevertheless does not erase accumulated fatigue and does not automatically "repair" insufficient sleep, inadequate energy intake, or poorly designed programming.

In Strongman, where one week can combine high volume, event training, maximal loads, and competitive stress, recovery is a systems problem. The hormone is part of the solution, not a replacement for the solution.

9. No, testosterone is not the only determinant of hypertrophy

For hypertrophy, mechanical loading, training volume, amino-acid availability, total energy intake, sleep, and recovery are essential. Systemic hormones modify the environment in which these processes occur, but they do not replace the mechanical stimulus.

Resistance-training research is important here precisely because acute rises in testosterone and other hormones after a session have not proved to be simple predictors of gains in strength and muscle mass.

10. No, a session that raises testosterone is not automatically a better session

Training with big exercises, sufficient volume, and moderate-to-high intensity can generate acute testosterone responses, especially in men. But a good session is judged by long-term progress and the stimulus-recovery relationship, not by how spectacular a 30-minute hormone curve looks.

A protocol can produce a large hormonal peak and still be poor for an athlete if it exceeds recovery capacity. Conversely, an excellent session for progress can produce only a modest acute hormonal change.

11. What testosterone does NOT do: it does not give you technique

You can have an excellent hormone profile and poor technique. Testosterone does not teach you to choose the optimal deadlift path, control a yoke, stabilize an axle, or synchronize breathing with bracing.

Those are adaptations of the nervous system and motor skill. Early in training, they can produce large strength gains without any need for a major change in basal testosterone.

12. What testosterone does NOT do: it does not guarantee tolerance to volume

An athlete with normal testosterone can still be under-recovered, under-fueled, sleep deprived, or affected by psychological stress. Hormone level cannot be used as permission to ignore recovery.

Fatigue is also not purely endocrine. There are central, peripheral, metabolic, neuromuscular, connective-tissue, and psychological components. One hormone cannot summarize all of these layers.

13. What testosterone does NOT do: it does not replace energy

Energy availability is one of the key variables for endocrine function. Severe energy restriction can disrupt the HPG axis, and in hard-training athletes this can occur even when intake looks large in absolute numbers.

This means that a very heavy athlete can still be in an energetically unfavorable state if training expenditure is enormous and food intake does not cover it.

14. What testosterone does NOT do: it does not repair lack of sleep

Testosterone secretion is closely linked to sleep and circadian rhythm. Insufficient sleep can alter the hormonal environment and reduce recovery capacity. Trying to compensate for short nights with hormonal "boosters" misses the problem at its root.

For the Strongman athlete, sleep should be treated as biological infrastructure. Without it, motor control, mood, recovery, and hormonal regulation are all put under pressure.

15. Testosterone and body fat

The relationship between testosterone and body composition is bidirectional and complex. Androgen deficiency can favor changes in lean mass and adipose tissue, while metabolic and body-composition changes can in turn influence the hormonal environment.

For that reason, it is not useful to reduce the issue to the formula "less body fat = automatically more testosterone." Strength athletes have very different body-mass requirements and weight histories.

16. Testosterone and age

Testosterone levels change with age, and acute exercise responses can differ between younger and older athletes. Aging does not, however, automatically mean losing the ability to respond to strength training.

A mature athlete can continue to gain or maintain mass and strength through intelligent programming, adequate nutrition, and recovery. There is no single testosterone number that alone determines an athlete's sporting age.

17. Testosterone in women: lower does not mean unimportant

Women produce less testosterone than men, but androgens remain relevant to female physiology. Hormonal interpretation in women is also linked to the menstrual cycle, ovaries, menopause, SHBG, and energy availability.

For a female Strongman athlete, hormonal function should be viewed together with energy availability and skeletal health. Reduced HPG function can have consequences that do not immediately appear in the total number of kilos lifted.

18. Testosterone and the difference between physiology and pharmacology

A clear line has to be drawn here. Pharmacological studies show that exposure to supraphysiological androgen doses can produce substantial increases in muscle mass and strength. That is not evidence that small physiological testosterone fluctuations after a training session have the same effect.

Dose, duration, concentration, and biological context change the problem completely. You cannot take the effect of a pharmacological regimen and use it as proof that a short physiological peak is the main driver of hypertrophy.

19. What happens to the HPG axis when exogenous testosterone is introduced?

When exogenous androgens increase androgenic signaling in the body, negative feedback can reduce GnRH, LH, and FSH. The testes receive less stimulation, endogenous production can fall, and spermatogenesis can be impaired.

This is why exogenous testosterone should not be presented as a simple "stronger version" of natural testosterone. It also changes the functioning of the axis that is supposed to produce endogenous hormone.

20. Testosterone and the androgen receptor: why the same value does not mean the same effect

Tissue response depends on the androgen receptor, its density and activation, local conversion to DHT or estradiol, and tissue characteristics. Because of this, two people with similar hormone levels can have different responses to training.

That does not mean blood tests are irrelevant. It simply means that blood provides a window into the system, not a perfect map of every muscle cell.

21. Total testosterone vs free testosterone

Some testosterone is tightly bound to SHBG, some binds more weakly to albumin, and a fraction circulates freely. When SHBG changes, the relationship between total testosterone and the fraction available to tissues can change as well.

For this reason, interpretation should consider the laboratory, measurement method, and clinical context. It is not correct to turn one result into a verdict on an athlete's "quality".

22. What does "low testosterone" really mean?

In medicine, male hypogonadism is not diagnosed from an isolated number alone. Guidelines recommend compatible symptoms and signs together with clearly and repeatedly low testosterone concentrations measured correctly, generally in the morning and under appropriate conditions.

Once a low level is confirmed, LH and FSH help distinguish a primary testicular problem from a hypothalamic-pituitary one. Good interpretation therefore looks for the cause, not just the label.

23. What a "testosterone booster" does NOT do

The market is full of products promising rapid testosterone increases. Evidence for many of these products is weak or inconsistent, and some may have unwanted effects or contain ingredients that do not match the promises on the label.

More importantly, a healthy athlete should not start from the assumption that a supplement is needed to "fix" hormones. Adequate nutrition, sleep, and management of training load have a much stronger physiological foundation.

24. Testosterone is not a masculinity score

A testosterone value does not measure character, courage, or sporting worth. An athlete does not become "more of a man" because the number is higher, and a lower result does not summarize identity or potential.

In sport, the relevance is physiological and clinical: what level does the body have, why, what symptoms are present, and how do the data fit into the broader picture?

25. Testosterone is not the only anabolic hormone

Insulin, IGF-1, growth hormone, thyroid hormones, and local muscle signals participate in growth, metabolism, and recovery. Each has a different function and a different time scale.

Instead of searching for the "king hormone," sports physiology becomes easier to understand when we view a network of signals that must remain compatible with the body's demands.

26. Testosterone and Strongman periodization

In a sport with heavy events, periodization must manage total stress. You are not trying to "maximize testosterone" in every session. You are trying to create enough stimulus for adaptation without exceeding recovery capacity.

In practice, this means alternating volume and intensity, controlling exposure to maximal efforts, eating enough, and using a recovery strategy that includes sleep and, when appropriate, reduced-load days.

27. Testosterone and competition

A Strongman competition can create an unusual combination of maximal exertion, adrenaline, pain, psychological stress, dehydration, heat, sleep loss, and irregular food intake. Interpreting a single hormone test immediately after competition without this context can lead to wrong conclusions.

Endocrine recovery makes sense when it is assessed over time, together with performance, sleep, appetite, mood, and symptoms.

28. What testosterone does and does NOT do: the mental table

DOES: support muscle mass, androgenic function, bone, erythropoiesis, and sexual function. DOES NOT: replace technique, guarantee recovery, replace energy or sleep, predict your progress by itself, or automatically turn a workout into a good workout.

DOES: contribute to a biological environment favorable to adaptation. DOES NOT: act as a universal performance meter. This distinction is the key to the entire episode.

29. How should a Strongman athlete view testosterone?

As an important parameter of the system, not an obsession. Physiologically normal testosterone is part of the terrain on which muscle, bone, and the nervous system can do their work. But performance is an orchestra, and testosterone is only one of the instruments.

If symptoms or persistently low values are present, the correct question is not "how do I raise it quickly?" but "why is it low, and what mechanism needs to be evaluated?" That is the difference between applied physiology and hormone marketing.

30. Conclusion

Testosterone does many important things: it supports muscle mass, bone, erythropoiesis, androgenic function, and reproduction. When levels are pathologically low, the consequences can be real and important. But when we talk about normal training, we cannot turn every transient testosterone rise into an explanation for every kilo added to the bar.

For Strongman, the lesson is simple and profound: testosterone can support the body's ability to build and maintain tissue, but it cannot lift the weight for you. For that, you need muscle, the nervous system, technique, energy, sleep, recovery, and years of adaptation.

Selected bibliography

1. Vingren JL, Kraemer WJ, Ratamess NA, Anderson JM, Volek JS, Maresh CM. Testosterone physiology in resistance exercise and training: the up-stream regulatory elements. Sports Medicine. 2010;40(12):1037-1053. DOI: 10.2165/11536910-000000000-00000.

2. Morton RW, Oikawa SY, Wavell CG, et al. Neither load nor systemic hormones determine resistance training-mediated hypertrophy or strength gains in resistance-trained young men. Journal of Applied Physiology. 2016;121(1):129-138. DOI: 10.1152/japplphysiol.00154.2016.

3. Morton RW, Sato K, Gallaugher MPB, et al. Muscle hypertrophy in resistance-trained men and circulating hormones: evidence that acute postexercise hormonal elevations are not required for hypertrophy. Journal of Applied Physiology. 2018.

4. Endocrine Society. Testosterone Therapy in Men With Hypogonadism: Clinical Practice Guideline. Recommendations on diagnosis using symptoms and consistently low measurements, and on evaluation of the underlying cause.

5. Lazarev A, Pujalte GGA, Philibert C, et al. Testosterone-Optimizing Strategies in Athletes. Sports Health. 2026;18(3):477-488. DOI: 10.1177/19417381251411933.