The Effects of Fabric Composition and Design on Thermoregulatory Responses and Comfort During Exercise in the Cold.

Abstract

2137 Selection of clothing for exercise in cool and cold weather is complicated by the need to balance heat production with effective heat dissipation. The ability of a fabric or clothing system to provide sufficient insulation while preventing significant increases in total body temperature and skin wetness are vital to ensuring thermal comfort. PURPOSE: This study was designed to assess the impact of fabric design on thermoregulatory responses, clothing moisture management, and comfort during moderate exercise in the cold. METHODS: Eight physically fit men (29.6 ± 4.1 years, 84.02 ± 5.35 kg) performed two identical 54-minute self-paced treadmill runs on separate days in an environmental chamber set to 1.7°C (35°F) and 65% relative humidity. Two different fleece tops were worn in a counterbalanced order with a 100% polyester micro-fiber t-shirt used as the base layer for each run. Both fleeces were made from a 100% polyester micro-fiber brushed fabric. One fleece (N) had a normal inner surface while the other (S) had uniform undulations covering the inside of the garment. Skin temperatures, at seven anatomical sites, and microclimate temperature between layers were monitored continuously. Heart rate was monitored continuously and recorded at 5-minute intervals. Nude and clothed weights were obtained before and after exercise to determine total and evaporative sweat loss. Pre- and post weights of base layer and fleece were measured to assess clothing moisture retention. Following each run subjects filled in a questionnaire, rating thermal and moisture comfort on a nine-point scale. RESULTS: Mean skin temperature was 0.25°C to 0.5°C lower for S during the exercise bout. Mean moisture retention for N (82.7 g.) was higher than S (70.0 g.) (p = 0.06). Mean moisture retention in the base layer when worn under N (88.1 g.) was higher than S (75.0 g.) (p = 0.07). Total sweat loss showed no significant difference between trials. Percentage of sweat evaporated was slightly higher for S. Subjects perceived both the fabric and their skin as remaining significantly dryer during and after exercise in S. Perception scores for overall liking were significantly higher for S (p<0.05). CONCLUSION: Reduced accumulation of moisture in the base layer and the fleece significantly improved thermal comfort when wearing S. Perceptual data indicated that subjects were able to detect the differences in moisture retention between the two garments. Comfort during exercise in this environment was positively affected by fabric composition and design.