Are running socks beneficial for comfort? The role of the sock and sock fiber type on shoe microclimate and subjective evaluations

This study evaluated the effect of socks (different in fiber type) and the effect of not wearing a sock on perceptions of thermal comfort in relation to changes in foot skin temperature and shoe microclimate (temperature and humidity) during rest and exercise. Ten females completed five trials on separate occasions. Four socks (cotton, wool, polyester, Coolmax) and no sock were evaluated. Trials were conducted at 23°C, 50% relative humidity and consisted of rest (10 min seated), treadmill running (40 min, 7.5 km·h⁻¹) and recovery (15 min seated). Foot skin temperature and shoe microclimate were measured at seven sites on the right foot. Foot skin hydration was measured at nine foot sites. Perceptual responses were recorded. Foot thermo-physiological and foot perceptual responses were similar for all sock conditions (p > 0.05). Similar foot thermo-physiological responses were also observed between the sock and no sock conditions (p > 0.05). Interestingly, however, not wearing a sock resulted in greater perceptions of foot wetness, stickiness and discomfort (p < 0.05). As tactile interactions caused by foot movement within the shoe are strong predictors of foot wetness perception (a key contributor to wear discomfort), socks are important in reducing the tactile cues generated. The sock is therefore an important area for development and relevant for overall improvements in footwear comfort.