Effects of ventilation design on thermal comfort performance and breast displacement for sports bras

Most of the research on the thermal comfort of sports bras has focused on fabric differences, whereas the effect of ventilation has yet to be investigated. This study aimed to investigate the effects of ventilation design on the thermal comfort performance and breast displacement. Based on the physiological nature of breast movement and airflow in exercising women, four sports bras with different necklines and ventilation holes were designed. The thermal comfort performance and the reduction of breast displacement of these four bras were compared. Nine healthy women exercised in random order with four sports bras, and then performed a 20-min short duration high-intensity exercise and rest to recover under thermoneutral conditions. Skin temperature and humidity, body core temperature, the reduction of breast displacement and thermal psychological subjective sensations were investigated during the whole experiment. The results indicated that deepening and widening the neckline could effectively increase the airflow pumped in from the neckline, while the ventilation holes could effectively direct the airflow from the neckline to the middle and bottom area of the breasts, significantly reducing the skin temperature, skin humidity and body core temperature ( P < 0.05). In addition, widening the neckline would significantly reduce the reduction of breast displacement, whereas deepening would not. A slightly but not significant increase of the psychological subjective sensation during exercise was observed. These results provide novel information that appropriate application of ventilation design in sports bras could effectively improve the thermal comfort performance without reducing the function of support to benefit exercising women.