Viscose as an alternative to aramid in workwear: Influence on endurance performance, cooling, and comfort

Workwears are required to maintain optimum performance during dangerous, exhausting activities (e.g. those involving the fire brigade or police). The purpose of the present study was to compare two workwears (A and B) composed of underwear and outerwear with different fiber blends (A: 100% aramid; B: combination of fire resistant (FR) viscose/merino wool underwear and FR viscose/aramid outerwear) during strenuous physical activity. In a climatic chamber (25℃, 50% RH) participants had to walk on a treadmill until exhaustion occurred. Weight measurements were made for calculating evaporation, sweat residue, and sweat distribution. Endurance performance was assessed by time to exhaustion. Core temperature, heart rate, lactate, thermal comfort, microclimate between skin and underwear, surface temperature of the outerwear, and perceived exertion were also measured. The tested workwears caused no significant differences in time to exhaustion, core temperature, and thermal comfort. Sweat distribution differed significantly in the workwears. The underwear of workwear B caused less moisture accumulation in the outerwear and this may be a beneficial safety feature for the prevention of hazardous burns of the skin. Moisture accumulation in the outerwear may reduce thermal insulation and increase the possibility of evaporation whereby hot steam may move to the skin. The potential protective feature of the FR viscose/merino wool blended underwear and the economical price of viscose support the use of fire resistant (FR) viscose blended fabrics in workwears.