Thermoregulatory Responses during Competitive Marathon Running.

摘要

To assess thermoregulatory responses occurring under actual marathon racing conditions, rectal (T sub re) and five skin temperatures were measured in two runners approximately every 9 min of a competitive marathon run under cool conditions. Race times and total water losses were: funner 1 = 162.7 min, 3.02 kg; runner 2 = 164.6 min, 2.43 kg. Mean skin temperature was similar throughout the race in the two runners, although they exhibited a marked disparity in temperatures at individual skin sites. T sub re plateaued after 35-45 min (runner 1 = 40.01 - 40.1C, runner 2 = 38.9 - 39.2 C). While runner 2 maintained a relatively constant level for the remainder of the race, runner 1 exhibited a secondary increase in T sub re. Between 113 and 119 min there was a precipitous rise in T sub re from 40.9 to 41.9 C. Partitional calorimetric calculations suggested that a decrease in sweating was responsible for this increment.