Abstract
To establish the accuracy and precision of deep forehead temperature (Tch) measured by the zero-heat-flow method, Tch was compared with the esophageal temperature (Tes), as an index of core temperature, during 30 min of a cycling exercise at 20% and 50% of maximal oxygen uptake in seven male subjects under 28°C, 24°C, and 20°C environmental temperature conditions. The Tes was measured by placing a thermocouple probe in the esophagus through the subject’s nostril, and Tch was also measured by using Coretemp thermometer probe fixed on forehead. Tch significantly correlated with Tes, correlation coefficient (r2) between two parameters under 28°C, 24°C, and 20°C environmental temperature conditions were 0.555, 0.647, and 0.491, respectively. From the Bland-Altman analysis, the off set (Tes-Tch) and the precision were significantly lower, and also delay time was significantly (p<0.05) longer according to the lowing ambient temperature or exercise intensity. These results suggest that the accuracy and precision of Tch that estimate to Tes were affected by environmental temperature and exercise intensity.
