Bryan Johnson· Author
A single sauna session (20 min at 85°C) reduced sperm counts, full recovery took up to 5 weeks.
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The evidence is convergent. Multiple independent sources reach the same conclusion, the underlying mechanism is well-characterized, and even the field's most cautious voices treat it as worth doing.
A single sauna session (20 min at 85°C) reduced sperm counts, full recovery took up to 5 weeks.
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A single sauna or hot bath at 80-90 °C can drop progressive motility 40-60% two months later.
A single sauna or hot bath at 80-90 °C can drop progressive motility 40-60% two months later.
A single sauna or hot bath at 80-90 °C can drop progressive motility 40-60% two months later.
The good news: these changes were reversible at 3 months.
So saunas is not underwater. It's not submersion. And then I would say steam rooms, showers are probably fine.
4–7 sauna sessions per week, 20 minutes at 80°C+, reduce cardiovascular mortality risk by 40% over a decade.
Regular sauna use raises BDNF and improves verbal memory in older adults.
Sauna protocols only generate the longevity effect when sessions exceed 30 minutes.
Hot-tub bathing yields cardiovascular benefits comparable to traditional Finnish sauna at matched core-temp dose.