Dynamic behavior of textiles during multiple work–rest sequences

The choice of apparel used in outdoor sports activities, and regular exercise, can have a profound influence on the thermal perceptions and comfort of the wearer. People perform different types of exercise, many of them outdoors. Some activities, such as hiking, cycling, and rockclimbing can include several bouts of high activity followed by rest periods (stop–go sports). Current test standards and research articles can capture the dynamic behavior of different fabrics during water uptake and spreading using thermal testing equipment, but do not reflect the multiple cycles of activity and rest experienced in stop–go sports. Therefore, in this work we have modified an existing sweating guarded hot plate test protocol (SGHP) to enable the thermal performance of three fibers – polyester, cotton, and wool – to be differentiated for stop–go sportswear. By controlling the sweating and non-sweating durations on the SGHP, multiple cycles of work–rest could be explored. It was also found that the duration of work and rest also had impacts on the patterns observed in the heat flux curves ( p = 0.00001), especially for the polyester sample. Using R ² to determine variability, data reflected that wool offered a steadier state in cooling throughout the entire test while polyester and cotton exhibited large shifts in cooling between the work and rest periods. Overall, this work has demonstrated a method to evaluate different fabrics, via differences in cooling behavior, during several work–rest cycles. Area-under-the-curve and thermal buffering capacity metrics can provide valuable information that could help manufacturers of sporting apparel choose the most effective fabrics for their sporting scenarios. For ideal data results, at least one standard time sequence work–rest should be included and further could be adapted to better represent the scenario being considered.