Evaluating the effects of drafting formations on athletes' heat dynamics and performance via coupled CFD and thermoregulation model

Abstract

Research indicates that drafting enhance performance across various sports. Current studies concentrate on drafting impact on reducing drag, with limited research on thermoregulation and sweating. This article explores how drafting formations affect the athlete's microenvironment using CFD and thermoregulation model. This study investigates how drafting influences heat production, dissipation, and sweating while maintaining consistent core and skin temperature, considering the impact of drag reduction on mechanical work. The average $h_c$ during race walking alone is the highest at 37.34, followed by double formations 1, 2, and 3, which are 36.34, 36, and 34.74 respectively. This represents a decrease of 2.7 %, 3.6 %, and 7 %. These reductions can be attributed to the lower Reynolds number and turbulent diffusion coefficient observed in the mainstream. Compared to race walking alone, in double formations with varying distances, core athlete experienced increased sweating heat dissipation by 0.23 %, 0.24 %, 0.28 %, and skin blood flow by 0.31 %, 0.39 %, 0.65 %. Additionally, the pelvis is identified as the most impacted area. However, reduced drag leads to less metabolic heat production, resulting in decreased sweating and skin blood flow. Compared to race walking alone, the sweating heat dissipation is reduced by 3.44 %, 4.71 %, and 6.72 % in double formations at varying distances, while skin blood flow is reduced by 3.16 %, 4.38 %, and 6.39 %. These changes positively impact performance. Additionally, the drag reduction rate is inversely correlated with the percentage difference in skin blood flow and sweating heat dissipation, with negative correlation coefficients of 0.116 and 0.119, respectively. Therefore, this article emphasizes how drafting reduces sweating and skin blood flow, highlights the importance of thermoregulation, and offers valuable guidance for training and hydration strategy.