Comparative effects of two heat acclimation protocols consisting of high-intensity interval training in the heat on aerobic performance and thermoregulatory responses in exercising rats.Acclimation resulting from low- to moderate-intensity physical exertion in the heat induces several thermoregulatory adaptations, including slower exercise-induced increases in core body temperature.  However, few studies have investigated the thermoregulatory adaptations induced by high-intensity interval training (HIIT) protocols.  Thus, the present study aimed to compare the adaptations in rats' thermoregulatory parameters and aerobic performance observed after two different heat acclimation regimens consisting of HIIT protocols performed in a hot environment.  The workload performed by the rats and their thermoregulatory efficiency were calculated.  The latter finding indicates better thermoregulatory efficiency in trained animals.  In conclusion, the two HIIT protocols induce greater thermoregulatory adaptations and performance improvements than passive heat exposure. 
THERM