The simulation of human core temperature

Two fit subjects performed two cycle-ergometer exercise bouts, one of 200 W for 48 min with a following 12-min recovery phase and one of 250 W for 30 min with a subsequent 15-min monitored recovery period. Experiments were performed in ambient conditions of 18 +/- 1 degrees C, 52% relative humidity +/- 5% and 0.5 m.s-1 + 0.5 air velocity (mean +/- range). Experimental values obtained from rectal and tympanic temperature sites were compared with simulation figures produced from a FORTRAN model of human thermoregulation. Data obtained provide qualified experimental support for the concept of a simple feedback model to simulate human core temperature during exercise in ambient temperatures below 20 degrees C.