2007, Piran, Slovenia

Environmental Ergonomics XII
Igor B. Mekjavic, Stelios N. Kounalakis & Nigel A.S. Taylor (Eds.), © BIOMED, Ljubljana 2007
64
THERMOREGULATORY AND SUBJECTIVE RESPONSE TO
HYPEROXIA DURING SUBMAXIMAL EXERCISE
Ivan Galias Solano, Yutaka Tochihara and Tsuneyuki Yamamoto
Departmen of Ergonomics, Faculty of Design, Kyushu University, Fukuoka, Japan
Contact person: ivan629@gsd.design.kyushu-u.ac.jp
INTRODUCTION
Several studies have investigated the varied effects of hyperoxia during physical
performance. However, to date, studies investigating how hyperoxia affects human
thermoregulation during exercise are lacking. Thus, this study was conducted to study
the effect of hyperoxia on thermoregulatory and subjective responses of human
subjects during exercise.
METHODS
Eight, healthy male students (22-26 yrs.) performed graded exercise test (GXT) a
week prior to the experiment to determine VO2max. During the actual experiment,
the oxygen fraction (FO2) in the climatic chamber was set at 0.21 and 0.30 O2. The
subjects cycled on an ergometer for 30 min at 40 and 60%VO2max under the 2
different FO2 conditions on different days and in random order. Thus, four conditions
were established in this experiment, namely: exercise at 40% VO2max intensity at
0.21 (N40) and 0.30 (H40) O2 fractions; and exercise at 60% VO2 max at 0.21 (N60)
and 0.30 (H60) O2 fractions. The chamber was set at 26ºC ambient temperature and
50% relative humidity in all conditions. Measurements included rectal temperature
(Tre), skin temperature at 7 sites, mean skin temperature (Tsk), laser Doppler flowmeter
(LDF) and mean sweat rate (Msw) on the forearm, back and thigh, heart rate (HR),
blood pressure (BP) and body weight loss (BWL). Subjective parameters were
thermal comfort, thermal sensation, rate of perceived sweating, dyspnea grade and
rate of perceived exertion (RPE).
RESULTS
Figure 1. Time courses of rectal temperature (Tre) and mean skin temperature (Tsk) while performing
exercise at 40%VO2max in 0.21 (N40) and 0.30 FO2 (H40); and 60% VO2max in 0.21 (N60) and
0.30% FO2 (H60). Values are means±SD. “time:p