I was listening to a Ben Greenfield podcast a while back and it got me thinking about how little most men know about testosterone — and how much of what they think they know is either wrong or oversimplified. The topic deserves a proper treatment.
Here’s what actually moves the needle when it comes to naturally optimising your testosterone levels.
Why testosterone matters beyond the gym
Most people associate testosterone with muscle mass and gym performance — and it does drive both. But testosterone plays a much broader role than that. It regulates energy levels, mood, libido, bone density, cognitive function, and cardiovascular health. Low testosterone isn’t just a gym problem. It affects quality of life across the board.
The decline is real and gradual. Testosterone levels peak in the late teens to early twenties and decline roughly 1% per year from around age 30. By 40, many men are running at meaningfully lower levels than they were a decade earlier — and the lifestyle factors that accelerate that decline are almost entirely avoidable.
One other thing worth noting: after the birth of a child, a man’s testosterone drops significantly. It’s a documented biological response — the body is shifting into caregiving mode. It doesn’t have to stay that way, but it does explain why many new dads feel like they’ve lost something in the first year.
Training: what actually works
Lift heavy, rest properly
The most effective training stimulus for testosterone is heavy compound lifting with adequate rest between sets. Squats, deadlifts, bench press, rows — movements that recruit large amounts of muscle tissue trigger the greatest acute hormonal response. Longer rest periods (2-3 minutes) produce better testosterone responses than short rest periods with metabolic stress.
Train your legs. Seriously. Lower body training — particularly squats and deadlifts — produces a far greater testosterone response than upper body work alone. Skipping leg day isn’t just a physique mistake. It’s a hormone mistake.
Don’t overtrain
Chronic overtraining suppresses testosterone. If you’re training six or seven days a week with high intensity and inadequate recovery, your cortisol rises and your testosterone drops. More is not better. Three to four well-structured sessions per week with proper recovery days will produce better hormonal outcomes than grinding through daily punishment sessions.
Sleep: the most underrated lever
The majority of testosterone production happens during sleep — specifically during deep sleep cycles. Multiple studies have shown that restricting sleep to five or six hours per night for just one week reduces testosterone levels by 10-15%. That’s roughly the equivalent of ageing 10-15 years.
Prioritising sleep is not optional if testosterone is a concern. Seven to nine hours in a cool, dark room, consistent sleep and wake times, and eliminating screens in the hour before bed are the non-negotiables. No supplement will compensate for chronic sleep deprivation.
Body composition
Adipose tissue (body fat) — particularly visceral fat around the abdomen — converts testosterone to oestrogen via an enzyme called aromatase. Higher body fat means more aromatase activity, which means lower testosterone. Reducing body fat, particularly abdominal fat, directly increases bioavailable testosterone.
This creates a virtuous cycle: lower body fat → higher testosterone → easier to build muscle → higher metabolic rate → easier to maintain lower body fat. The problem is most people try to address the entry point incorrectly. The most effective path is resistance training and nutrition, not excessive cardio.
Nutrition
Don’t fear dietary fat
Testosterone is synthesised from cholesterol. Diets that are very low in fat — particularly saturated fat — are associated with lower testosterone levels. Healthy fat sources (eggs, red meat, olive oil, avocado, nuts) are not the enemy. The low-fat diet era did a lot of damage here.
Zinc and magnesium
Zinc is a critical cofactor in testosterone production. Deficiency is relatively common, particularly in men who sweat heavily through exercise. Good dietary sources include red meat, shellfish (oysters are exceptionally rich), pumpkin seeds and legumes. Magnesium supports testosterone by reducing cortisol and improving sleep quality — most people are mildly deficient.
Limit alcohol
Alcohol directly suppresses testosterone production and elevates cortisol and oestrogen. Regular moderate-to-heavy drinking is one of the most reliable ways to lower your testosterone. Reducing alcohol is one of the fastest lifestyle interventions for improving levels.
Stress management
Cortisol and testosterone have an inverse relationship — when one is chronically elevated, the other is suppressed. Chronic work stress, relationship stress, financial pressure, and inadequate recovery all drive cortisol up and testosterone down. This is the physiological mechanism behind why chronically stressed men feel flat, low energy, and disengaged.
Exercise helps manage stress — but only if recovery is adequate. Meditation, deliberate downtime, quality sleep, and strong social connection all reduce chronic cortisol. These aren’t soft wellness suggestions. They’re hormonal interventions.
What about testosterone replacement therapy?
TRT is a valid medical intervention for men with clinically low testosterone confirmed by blood testing. It’s not a shortcut for men with levels in the normal range who want more. Before considering TRT, optimising the lifestyle factors above is essential — many men who think they need TRT find that proper training, sleep, body composition and nutrition gets them where they want to be without medical intervention.
If you’ve done the work on lifestyle and still feel the symptoms of low testosterone, get your levels tested by a GP. It’s a simple blood test and worth doing.
Related reading: Strength Training Over 40 · Why Rest Days Are Part of the Program · My Science-Based Sleep Routine
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