Effects of Moisture Absorption of Clothing on Pitching Speed of Amateur Baseball Players in Hot Environmental Conditions

The purpose of this study was to investigate the effects of the hygroscopic properties of clothing material on pitching speed and some physiological responses in amateur baseball players. The experiments were performed on four male players of a regular high school baseball team and comprised two clothing types with different moisture absorption properties, namely, cotton (Type C) and polyester and polypropylene (Type P). One test session was conducted with seven innings, with a 5-minute rest time between each inning. During each inning the test subject pitched 20 balls with a 20-second interval between each pitch. From the results, in the hot environments, the trained baseball players tended to pitch balls with higher speed and less deviation of speed when wearing Type C clothing, especially in the second session. Type C clothing with a higher moisture regain compared to Type P clothing may have diminished accumulated thermal induced fatigue in the subjects.