Reference works on longevity practices
Most writing about longevity practices is either marketing or a shrug. This is neither. Each entry is a full reference work: the mechanism from first principles, the peer-reviewed evidence graded honestly, the strongest counterargument given equal room, and the marketing claims checked against the physics.
Traditional and infrared sauna compared from first principles. Eight chapters covering heat-transfer physics, the full evidence base outcome by outcome, twenty-two thermal room types, a buying decision with real installed costs, design and engineering specifications, protocols, and safety including drug interactions.
Cold plunge, contrast circuits, and the question the sauna literature keeps flagging as unanswered: the heat-plus-cold combination is the traditional practice and remains, in the reviewers' own words, poorly investigated. Includes the cold-after-lifting question.
Wavelengths, irradiance, dose, and the gap between what photobiomodulation trials actually used and what a panel bolted into a cabin wall delivers. The dosing question that sauna marketing skips.
Does a PEMF mat do anything measurable. Does red light. Do the cheap versions work well enough. One person, one metabolic condition, documented honestly, including the null results.
Six rules, applied to every entry. They are the reason these read differently from the rest of the category.
Nothing here is monetised through product recommendations, and there are no referral links in any entry. If that changes, it will be disclosed at the top of the affected page rather than buried in a footer.
Buying a sauna, a plunge, a light panel. You want to know what the evidence actually supports before a four-figure decision, and you have noticed that every review site is paid.
Spa, hotel, gym, clinic. You need dimensional targets, heater sizing, ventilation schemes, capacity planning and code references, not lifestyle photography.
You want the citation, the sample size and the primary source, and you want to be told when the one randomised multicentre trial missed its primary endpoint.