How reference ranges are set — and why they fail athletes
When a lab sets a reference range for testosterone, they test a large sample of men and calculate the range that covers roughly the middle 95%. Those men include sedentary adults, men in their 60s and 70s, men with undiagnosed metabolic conditions, and men who simply have naturally low testosterone for various reasons. A result of 11 nmol/L falls within the standard range. Your report says normal. But the evidence suggests that testosterone below 15 nmol/L in active men is associated with increased fatigue, reduced muscle protein synthesis, slower recovery from training, impaired cognitive function, and reduced libido. None of those are markers of health — they're markers of suboptimality.
What optimal actually looks like
Research on performance and longevity generally points to 18–30 nmol/L as the range associated with the best outcomes for active adult males. For athletes and those prioritising body composition and performance, the upper portion of that range — 22–30 nmol/L — tends to be where training adaptation, recovery, and wellbeing are maximised.
Free testosterone matters as much as total
SHBG binds to testosterone and makes it unavailable to your cells. Two men can have identical total testosterone but very different free testosterone depending on their SHBG levels. A man with total testosterone of 20 nmol/L and high SHBG may have less biologically active testosterone than a man with 16 nmol/L and low SHBG.
What moves testosterone in the right direction
Sleep is the biggest lever — a week of sleeping under 6 hours per night can reduce testosterone by 15% or more. Resistance training, particularly compound movements, drives acute and chronic testosterone elevation. Body fat — particularly visceral fat — suppresses testosterone through aromatisation. Zinc, magnesium, and vitamin D all have supporting evidence for their role in testosterone production. Chronic stress, via cortisol, suppresses testosterone directly. Knowing your numbers is the starting point. Knowing what to do with them is the next step.