Clothing fabric effects on physiological and comfort responses
During exercise and in hot environments, the main cooling mechanism is through sweat evaporation. However, clothing can disrupt evaporation, which leads to decreased performance and in some cases can lead to heat illness. New fabrics and designs have been introduced with the purpose of improving thermoregulatory properties. One of those innovations is a channeled synthetic fabric. The first of three studies evaluated the effects of a channeled synthetic and synthetic t-shirts under a ballistic vest on physiological and comfort responses during exercise in a hot environment. Eight participants, in counterbalanced order, completed two simulated "industrial" protocols for three hours. The overall (0 - 180 min) change in rectal temperature was significantly (p = 0.04) lower with channeled synthetic shirt compared to a synthetic shirt. Additionally, overall change in thermal comfort (p = 0.05), sweating sensation (p = 0.06), and heart rate (p = 0.07) were, or tended to be more favorable throughout exercise with channeled synthetic compared to synthetic shirt. We also examined the effects of channeled synthetic shirt and synthetic cycling shirt effects on thermoregulation, thermal comfort, and heart rate. Eight participants attempted a 30-km cycling time trial. Results indicated significantly (p = 0.04, n = 8) smaller increase in rectal temperature from baseline to 15th km (first dropout) with the channeled synthetic shirt compared to cycling shirt. Also, the change in thermal comfort was significantly (n = 5, p = 0.03) lower with channeled shirt compared to cycling shirt from baseline to 30th km. A third study examined channeled compression shorts, compression shorts, and cycling shorts effects on thermoregulation, heart rate, and thermal comfort response during 30-km cycling trial in hot a environment. Eight participants completed a 25-km cycling trial. Results revealed no significant main effect for rectal or skin temperatures, heart rate, and thermal comfort between the three different types of shorts (n = 8, p > 0.05). In conclusion, wearing a channeled synthetic shirt provided better thermoregulatory or thermal comfort responses compared to synthetic shirt in two studies. Channeled compression shorts did not improve thermoregulatory or thermal comfort responses compared to cycling and compression shorts.