Thermoregulatory Response to Base-layer Garments During Treadmill Exercise 1

Abstract. The purpose of this study was to determine the thermoregulatory response to, perceived comfort and moisture management properties of, base-layer garments during intermittent treadmill exercise in controlled laboratory conditions. Seven males performed an intermittent treadmill protocol whilst wearing a base-layer hot garment, base-layer cold garment, a 100 % cotton t-shirt and bare-chested. Environmental temperatures were 20.6 °C ± 0.2 SD (ambient temperature) and 47.5 % ± 7.7 SD (ambient humidity). Mean torso skin temperature, rectal temperature, comfort rating, thermal sensation rating, rating of perceived exertion, garment moisture retention, and garment rate of evaporation were recorded. Garments were examined under a high magnification microscope in order to characterise physical differences. Mean torso skin temperatures post exercise were 28.5 °C ± 0.8 SD, 29.1 °C ± 0.4 SD, 29.8 °C ± 0.8 SD, 29.8 °C ± 0.8 SD for bare-chested, base-layer hot, base-layer cold, and cotton garment conditions respectively. Mean comfort ratings during exercise were 7.8 ± 0.6 SD, 8.1 ± 0.7 SD, 9.2 ± 0.7 SD, and 9.4 ± 0.6 SD for bare-chested, base-layer hot, base-layer cold, and cotton garment exercise conditions respectively. Mean increase in garment mass post exercise was 0.044 kg ± 0.032 SD, 0.052 kg ± 0.029 SD, and 0.066 kg ± 0.043 SD for base-layer hot, base-layer cold, and cotton garment conditions respectively. In conclusion, base-layer garment choice affects the physiological response to intermittent treadmill exercise. Specialist base-layer garments are a superior alternative to 100 % cotton t-shirts with respect to desired thermoregulatory response and wearer comfort