Wearing a Cooling Jacket During Exercise Reduces Thermal Strain and Improvesendurance Exercise Performance in a Warm Environment

Abstract

Hasegawa, H., T. Takatori, T. Komura, and M. Yamasaki. Wearing a cooling jacket during exercise reduces thermal strain and improves endurance exercise performance in a warm environment. J. Strength Cond. Res. 19(1):122-128. 2005.-The aim of the present study was to investigate the effect of wearing a cooling jacket on thermoregulatory responses and endurance exercise performance in a warm environment. Nine untrained male subjects cycled for 60 minutes at 60% V O 2 max (Ex1) and then immediately exercised to exhaustion at 80% V O 2 max (Ex2) in 32.0 Ϯ 0.2ЊC and 70-80% relative humidity. Four separate conditions were set during exercise: no water intake (NW), water intake (W), wearing a cooling jacket (C) and the combination of C and W (CϩW). Rectal temperatures (T re ) before Ex1 were not different between the 4 conditions, whereas at the end of Ex1 T re of CϩW was significantly lower than the C and W (p Ͻ 0.05). Mean skin temperature (T sk ) was significantly lower in C and CϩW than the NW and W during Ex1. Heart rate of C and CϩW were significantly lower than the NW and W, and rating of perceived exertion (RPE) in CϩW was lower than in the other conditions. Exercise time to exhaustion was significantly longer in CϩW than in the other conditions (NW Ͻ W, C Ͻ CϩW; p Ͻ 0.05), whereas T re at exhaustion was not different. Our results indicate that the combination of wearing a cooling jacket and water intake enhances exercise endurance performance in a warm environment because of a widened temperature margin before the critical limiting temperature is reached and also because of decreased thermoregulatory and cardiovascular strain. KEY WORDS. hot and humid environment, core temperature, skin temperature, body cooling

Effects of Half-Time Cooling Using a Fan with Skin Wetting on Thermal Response During Intermittent Cycling Exercise in the Heat

“…In the current study, the difference in m T sk after the 10 min of FAN wet intervention was 4.1 °C (60 min). A reduction in skin temperature leads to a reduction in peripheral skin blood, which results in a circulatory shift to central blood circulation [27] and may mitigate cardiovascular strain during exercise in the heat [28]. Some previous studies reported that a FAN wet cooling intervention during exercise in the heat reduces the HR [13,14].…”