The physiology of channel swimmers. 1955.

Abstract

This paper presents the results of three years’ study of some of the factors concerned in the ability to endure immersion in cold water. People showing unusual tolerance of cold have been compared with people showing unusual intolerance. In 1951 there was a swimming-race across the English Channel in which eighteen of twenty competitors swam from France to England in times ranging from 12 to 20 hours in water at 15.5C (60F). This is of great interest because records of shipwreck survivors show that persons immersed in the sea at 60F usually live only about 5 hours, and seldom more than 6 hours, death being due to hypothermia (Molnar 1946). The swimmers in the 1951 race all conformed to a certain physical type, very different from that of athletes who cover long distances on land by running, cycling, skiing, or mountain climbing. Some of the swimmers were frankly obese; others were of stocky build and had well-rounded contours concealing the muscular pattern.