Testosterone and Workout Performance: What the Data Actually Shows in 2026

Testosterone does improve muscle strength and lean mass in hypogonadal men — the evidence on that point is consistent. What the data do not support is the broader claim that TRT turns average training sessions into elite-level results, or that men with normal testosterone gain meaningful performance benefits from supplementation.

What Clinical Research Actually Demonstrates

The clearest findings come from men with documented low testosterone. A meta-analysis published in Gerontology found that testosterone replacement therapy produced statistically significant but modest strength gains in older or hypogonadal men — a pooled effect size of roughly Hedges' g = 0.21 [2]. That's real, but it's not dramatic. Intramuscular formulations showed a larger effect (g ≈ 0.74), likely because injectables like Depo-Testosterone achieve more stable, higher serum levels than transdermal options like AndroGel or Testim [2].

The NIH-funded Testosterone Trials (TTrials) — a seven-arm study of older men with low testosterone — reinforced this picture. Lean mass and some functional measures improved, but the gains were population-specific and contingent on baseline deficiency. In one trial of older obese hypogonadal men, total one-rep-max strength improved roughly 22–23% in both the testosterone and placebo arms when both groups followed an intensive lifestyle program — meaning testosterone added no incremental strength benefit on top of structured exercise [16]. If you're already training hard and eating well, fixing a borderline testosterone level is unlikely to be the variable that transforms your results.

For men exploring their options, hormone optimization treatment resources at AHF outline what evaluated protocols actually look like versus what's being marketed.

Endurance, Aerobic Capacity, and the Limits of the Data

The strength data are reasonably consistent; the aerobic data are not. In heart failure patients — a population where low testosterone is common — testosterone supplementation produced no statistically significant improvement in walking-test performance or peak VO₂ in a pooled analysis of eight trials [14]. The standardized mean difference for walking tests was 0.36 with a p-value of 0.07. That's a null result.

Where aerobic benefits do appear, they're tied to erythropoiesis: testosterone raises hemoglobin, which can improve oxygen-carrying capacity. The Endocrine Society Clinical Practice Guidelines on male hypogonadism acknowledge this effect while simultaneously flagging erythrocytosis as one of the primary monitoring concerns — hematocrit above 54% warrants dose reduction [10][19]. Xyosted (subcutaneous testosterone enanthate) carries specific labeling warnings about blood pressure elevation for the same reason [17].

The broader performance picture in healthy men is similarly deflating. A study examining testosterone levels and sprint performance in young men found no linear relationship between circulating testosterone and sprint time [4]. Natural variation in testosterone within the physiologic range simply doesn't predict athletic output in a clinically useful way.

For a deeper look at how TRT affects strength specifically, see our editorial coverage on whether TRT actually helps build muscle.

Who Actually Benefits — and How to Think About This Clinically

The performance benefits of testosterone are most reliable in men with confirmed hypogonadism — two low morning testosterone measurements plus clinical symptoms, per Endocrine Society guidelines. Men in that category can reasonably expect modest improvements in lean mass, some strength gains, and potentially better recovery. Bhasin et al. [2018, NEJM Testosterone Trials] demonstrated dose-dependent lean-mass and strength increases when testosterone was titrated from sub-physiologic to replacement levels — but the study also showed that supraphysiologic doses produce dramatically larger effects, which is precisely why those doses aren't used therapeutically.

For men considering TRT, the route-of-administration choice matters practically. Topical gels like AndroGel are convenient but can transfer to partners and show smaller strength effects in meta-analysis. Injectables produce larger anabolic effects but introduce peaks and troughs. SERMs like Clomid (clomiphene) or Enclomiphene/Androxal preserve fertility and endogenous testosterone production — worth considering for younger men whose primary concern is energy and body composition rather than severe hypogonadism.

Clinics affiliated with platforms like Marek Health typically run comprehensive panels — free testosterone, SHBG, hematocrit — before prescribing, which is the standard the evidence supports. You can also review best practices for TRT dosing and monitoring before your first appointment.

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Frequently asked questions

Does testosterone therapy improve workout performance in men with normal testosterone levels?

Testosterone therapy does not produce meaningful workout performance improvements in men whose testosterone levels are already in the normal physiologic range. The clinical evidence — including data from the Testosterone Trials and multiple meta-analyses — shows performance benefits are concentrated in men with documented hypogonadism. Using TRT as a performance enhancer in otherwise healthy men is both unsupported by the evidence and carries real cardiovascular and hematologic risks.

Which testosterone formulation is best for muscle and strength gains?

Injectable testosterone (such as Depo-Testosterone or Xyosted) produces larger strength gains than transdermal options like AndroGel, based on meta-analytic data showing an effect size roughly three times higher for intramuscular routes [2]. That said, injectables come with more pronounced hormonal fluctuations and specific safety considerations including blood pressure elevation with subcutaneous formulations. The "best" option depends on baseline health, monitoring capacity, and patient preference — not just the anabolic effect size.

How long does it take for TRT to affect strength and muscle mass?

Most men with hypogonadism see measurable increases in lean mass within 12–16 weeks of starting TRT, with strength improvements following a similar timeline. The Journal of Clinical Endocrinology & Metabolism (JCEM) and related literature suggest that body composition changes plateau over 12–24 months. Expecting dramatic strength gains in the first four to six weeks is unrealistic; the effect is a gradual normalization, not an acute performance boost.