Major League Baseball (MLB) continues to be a popular national sport. While much attention has been given to performance issues in MLB players, few studies have reported on their physiological characteristics, fitness levels and training patterns of thses professional athletes. The purpose of this study was to examine physiological data that were systematically and consistently collected over a 17-year period from MLB players to: 1) describe the trends in height, weight, percent body fat, fat mass, lean mass, and peak VO2 and to 2) compare these characteristics by player position.
