Heat Transfer Characteristics of Sports Apparel

The protective clothing and equipment required for certain sports may inhibit heat loss from the body and contribute to potentially harmful heat stress injuries. This study measured the thermal resistance (insulation) and evaporative resistance of a variety of sports ensembles worn for football, basketball, baseball, soccer, track, tennis, golf, and cycling. The thermal resistance was measured with a heated sweating manikin in an environmental chamber according to ASTM F 1291. The intrinsic insulation values (R_cl) ranged from a low of 0.018 m^2.0C/W for running/aerobic ensemble consisting of a sports bra and compression shorts to 0.152 m^2.0C/W for a football uniform. The intrinsic evaporative resistance values (R_ecl) ranged from 0.004–0.028 m^2.kPa/W for the same ensembles, respectively. Sports uniforms that cover a large portion of the body surface or provide impact protection substantially reduced heat loss from the body. The data presented in this paper can be used in the solution of heat balance equations to predict physiological responses of athletes when wearing uniforms under different conditions.