Physiology of Breath-Hold Diving and the Ama of Japan (Papers)
Authors: Herman Rahn, Tetsuro Yokoyama (Editors)
DOI / Source: 10.17226/18843
Date: 1965
Reading level: Intermediate
Why This Matters for Freedivers
This is one of the “foundation” collections in breath-hold diving science. Even though it’s old, it captures many core ideas that still matter today: how repeated dives, cold water, pressure, and breath-holding combine to stress the body, and how experienced divers adapt (or get injured). It’s also a goldmine for coaches and curious divers because it ties real-world diving patterns (depths, times, frequency) to physiology.
Synopsis
This isn’t a single research paper—it’s a full symposium proceedings volume from 1965 that brought together many of the early heavy-hitters in breath-hold diving physiology. The central focus is the Ama—traditional professional breath-hold divers in Japan (and also Korea’s diving women), who were (and still are) a real-world “natural experiment” in human adaptation to repeated breath-hold diving.
The book is valuable because it mixes three things you rarely get together in one place: 1) Ethnography and working reality (how the Ama actually dove: seasons, water temperature, harvest patterns, how many dives per hour/day, typical depths and durations). 2) Hard physiology (what happens to gas exchange, heart rate, blood flow, temperature regulation, kidney function, and mechanical limits of the chest and lungs). 3) Risk and limits (hypoxia hazards, the “breaking point” of breath-holding, and early thinking about decompression-type problems from repetitive breath-hold dives).
A particularly interesting thread running through the volume is how depth changes the rules compared with a simple breath-hold at the surface. Several contributions discuss why the gases you come up with after a deep dive can look “weird” compared to a pool static—because pressure and rapid ascent/descent change how oxygen and CO₂ behave in the lungs and blood during the dive. There’s also detailed attention to practical constraints: equalising the middle ear can limit descent speed, and the chest/lung mechanics set boundaries on how deep a human can go safely.
The volume is also historically important because it consolidates and translates (or references) work that was scattered or difficult to access internationally at the time. If you want to understand where many “classic” freediving physiology ideas originally came from—diving reflex, cold-water stress, repeated-dive fatigue, and early discussions of taravana and decompression stress—this collection is one of the main roots.
Abstract
This edited symposium volume (1965) compiles multiple papers on the physiology of breath-hold diving with a special focus on the Ama of Japan and comparable diving communities. Topics include diving patterns and occupational context, gas exchange during breath-holding and deep dives, hypoxia risk and the breaking point of breath-holding, mechanical limits of depth, cardiovascular and renal responses to immersion, temperature regulation in cold water, metabolic and energy costs of diving work, and early discussion of syndromes and decompression-related concerns linked to repetitive breath-hold diving.