Author(s): LI, H., HUANG, Y., Institution: BEIJING SPORT UNIVERSITY, Country: CHINA, Abstract-ID: 1305

INTRODUCTION:
Managing heat and moisture is critical for athletic performance and thermal comfort during prolonged exercise. While traditional quick-dry (QD) fabrics focus on moisture wicking, Phase Change Materials (PCMs) offer active temperature regulation by absorbing and releasing latent heat. This study evaluates a specialized cotton fabric integrated with 30% PCM compared to standard QD apparel. The objective was to quantify the differences in metabolic indices, sweat dynamics, and subjective sensations during 30 minutes of constant-power cycling under controlled environmental conditions (24 degrees C, 45% RH).
METHODS:
Seven healthy male subjects (Age: 22.11 +/- 1.67 years; VO2max: 55.20 +/- 7.08 ml/min/kg) were recruited. In a randomized crossover design, subjects performed two 30-minute cycling sessions at 60% VO2max (159.71 +/- 20.63 W). Both garments (30% PCM-integrated T-shirt and a standard QD T-shirt) were provided by Li-Ning Co., Ltd. Metabolic parameters were measured via the Cosmed K4b2 system, heart rate via Polar H10, and back skin microclimate (temperature and humidity) via DS1923-F5 sensors. Statistical analysis, including paired t-tests and Pearson correlation, was conducted using R 4.4.1 (alpha = 0.05).
RESULTS:
The PCM fabric demonstrated significantly lower sweat retention (30.22 g less; p = 0.010) and a reduced sweat absorption ratio (3.92% lower; p = 0.004) compared to the QD fabric, despite similar total body sweat loss. Physiologically, the PCM fabric was associated with a significantly lower heart rate (decrease of 5.83 bpm; p = 0.027) compared to QD. Although no significant differences were observed in VO2, respiratory quotient, or skin temperature, VO2 was found to be positively correlated with garment sweat absorption (r = 0.564, p = 0.034) and subjective comfort (r = 0.669, p = 0.009). Subjectively, the PCM fabric significantly reduced the Rating of Perceived Exertion (RPE) post-exercise (p = 0.011).
CONCLUSION:
The findings suggest that 30% PCM integration enhances the moisture transfer efficiency and heat management of athletic apparel. By minimizing sweat retention within the fabric and reducing cardiovascular strain (as evidenced by the lower heart rate), PCM-integrated clothing provides superior physiological support compared to conventional quick-dry materials. In conclusion, at identical exercise intensities, PCM fabrics offer improved thermal comfort and reduced physical exertion, making them a more effective choice for moderate-to-high intensity exercise.