Effects of bidirectional thermoregulation materials on sport efficacy, physiology, and psychology in hot and cold environments

Abstract

Bidirectional thermoregulation materials can absorb or release heat in different external environments and automatically adjust the temperature of human body, while are less used in daily and sports functional clothing. In order to further study their impact on lower limb movement, thermal performance of thermoregulation and ordinary fabrics were compared, and human wearing experiments were conducted in cold and hot environments (15 °C and 30 °C). The results showed that thermoregulation sports pants had better thermal insulation with moisture and air permeability performance in both environments. The cardiopulmonary ventilation was 1.06 L higher (P < 0.01), and electromyographic amplitude was 4.64 µV lower at 15 °C and 6.59 µV lower at 30 °C (P < 0.05), indicating lower muscle fatigue. The microenvironment temperature of wearing thermoregulation pants was 0.2 °C higher at 15 °C, and 0.3 °C lower at 30 °C. Heart rate was significantly lower and blood oxygen saturation ranged from 98% to 100% (P < 0.05), which may be attributed to higher thermal resistance of 13.9 m²∙K∙10⁻³/W and moisture permeability of 30.5 g/m²/h of thermoregulation fabrics, reflecting better cardiopulmonary function during exercise. The temperature and humidity microenvironment were better than those of ordinary pants. Although there was no significant difference in thermoregulation, it had indeed a process of regulating temperature in both environments. The subjective sensory evaluation was consistent with the results of thermoregulation. This study helps to understand regulatory roles of thermoregulation fabrics in cold and hot environments, as well as impacts on human physiology and psychology, and effects of thermoregulation clothing on sport efficacy.