ABSTRACT

　This study aimed to compare the effects of neck cooling using Peltier elements or internal cooling achieved by ingesting ice slurry during exercise on thermal strain in hot conditions. Eight healthy male participants underwent a randomized crossover trial with two conditions:（1） internal cooling（INT trial） and（2） neck cooling using a Peltier-based neck cooler （NECK trial） . Participants performed 45 min of cycling exercise while monitoring rectal temperature, tympanic temperature, mean skin temperature, heart rate, thermal sensation, thermal discomfort, perceived exertion, and reaction time. The results showed that in the NECK trial, neck skin temperature significantly decreased from 5 min after exercise onset. However, rectal temperature remained elevated in 40 min. Thermal sensation was significantly improved in the NECK trial up to 20 min, but the INT trial showed significantly lower at the 40-min. No significant differences were found in thermal discomfort, perceived exertion, or reaction time. These findings suggest that Peltier-based neck cooling effectively improves thermal sensation in the early stages of exercise but has limited effects on deep body temperature regulation. For effective heat stress prevention, combining neck cooling with internal cooling or other body cooling methods may be necessary.

DECENTE SPORTS SCIENCE Vol.47/The DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE