To investigate the effects of clothing on thermoregulation, we analyzed the differences in temperature response between perfusing a tube-lined suits (PTLS) and fencing uniforms (FUT) during exercise in a hot environment, and determined an optimal perfused water temperature in PTLS. Seven male subjects performed three session of 20- min cycle exercise at light intensity (250W/m²) in a room maintained at 28 ℃ (wetbulb globe temperature, WBGT). Esophageal (Tes) and mean skin temperature (Tsk), heart rate (HR), cardiac output (Q), oxygen uptake (VO₂), thermal sensation (TS), and dehydration (DEH) were measured under four conditions, with two sets of clothing, FUT and PTLS perfused water at 14 (PT14), 20 (PT20), and 26 (PT26) ℃. The Tes during exercise was significantly (p<0.01) higher in FUT than in other conditions. However, there was no significant difference in Tes between PT14, 20, and 26. The Tsk significantly (p<0.01) rose in FUT, and fell in PT14〜26 according to the falling water temperature perfused in PTLS. The HR, TS and DEH were significantly (p<0.01) higher in FUT than in other conditions, and also significantly (p<0.01) higher in PT26 than in PT14 and 20 while these values were similar between PT14 and 20. The Q and VO₂ during exercise showed no significant difference between the four conditions. These results show that perfusing water at 20℃ in PTLS was the most effective in cooling body temperature during light exercise in a hot environment. Thus, PTLS would be useful for athletes to prevent heat disorders during sports activities in heat.

DESCENTE SPORTS SCIENCE Vol.22/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE