It is more commercially convenient to sell a capsule than to talk about sleep. But the effect sizes are not comparable, and pretending otherwise would make everything else on this site less trustworthy.
Sleep
In a frequently cited study, young healthy men restricted to five hours in bed for one week showed daytime testosterone fall by 10–15% — a decline comparable to ageing 10 to 15 years, produced in seven nights.
Most testosterone is produced during sleep, tied to sleep architecture rather than to clock time. Fragmented sleep suppresses it even when total hours look adequate, which is one reason untreated sleep apnoea so reliably lowers testosterone.
Body composition
Adipose tissue converts testosterone to oestradiol and suppresses the pituitary signal that drives production. The relationship runs both ways — low testosterone promotes fat gain, which further lowers testosterone.
Meaningful weight loss raises testosterone reliably in men who carry excess weight. It is one of the few interventions that addresses cause rather than replacing output.
Resistance training
Worth being precise here, because this is widely oversold. Resistance training produces a short-lived post-exercise testosterone rise, and there is little evidence that this transient spike drives the adaptations people attribute to it.
What resistance training does do is improve body composition, insulin sensitivity, bone density, sleep quality and mood. Those effects are large and well established, and several of them raise testosterone indirectly. The mechanism is not the post-workout spike.
Alcohol
Regular heavy drinking lowers testosterone through direct testicular effects and through liver impact on SHBG. Occasional moderate drinking has little measurable effect. Sustained intake does.
For women in perimenopause
The same foundations apply, with a shift in emphasis. Resistance training and adequate protein matter increasingly as oestrogen falls, because bone loss accelerates and muscle mass declines. Weight-bearing exercise is among the few interventions shown to slow that.
None of this substitutes for HRT where it is indicated. It sits alongside it.
Sources
Leproult R, Van Cauter E (2011), JAMA
One week of sleep restriction to five hours reduced daytime testosterone by 10–15% in healthy young men.
NICE Clinical Knowledge Summary: Obesity
Metabolic and endocrine effects of excess adiposity, including hypogonadism.
UK Chief Medical Officers' physical activity guidelines
Resistance training recommendations and effects on bone density and metabolic health.
