In briefMajor League Baseball players were divided into control (n=6) and experimental groups (n=14) during the 1978 season. The experimental group participated in a strength training program in addition to game activities. The control group participated only in games and game-related activities. At the end of the season members of the experimental group were significantly stronger than members of the control group and had reduced absolute and relative body fat and increased lean body weight. They also had a higher degree of muscle symmetry between antagonistic muscle groups. Improvements in strength occurred without reducing range of motion or increasing muscle bulk.