The importance of throwing velocity (TV) is not limited to just baseball pitchers. Advantages of having greater TV can aid a team defensively in multiple ways. PURPOSE: To examine TV of high school (HS) baseball players over an 8-week preseason training program while participating in 6d/wk of baseball practice. METHODS: Twenty-one HS baseball players (age = 15.8 ± 1.0 yr) were randomly assigned by a stratified sample technique to 1 of 2 training groups. Group 1 (n = 10) and Group 2 (n = 11) performed the same progressive full-body resistance exercises while training 3x/wk for 8 wk according to a stepwise periodized model prior to the start of their spring baseball season. Additionally, Group 1 performed a progressive throwing program with a standard 5 oz baseball, while Group 2 performed an over-weighted throwing program with a 7 oz and 5 oz ball at a 2:1 ratio (heavy and standard). Volume began at 54 throws and increased by 6 throws every 2 weeks for the 8-week study. By week 7 the volume was 72 throws. All training was conducted while the HS baseball team was practicing 6 d/wk. TV was measured with a Jugs radar gun. Bat velocity was recorded with a SETPRO SPRT5A, while batted-ball velocity was recorded with a Stalker Pro radar gun. One repetition maximum (1 RM) parallel squat and bench press were measured with standard Olympic weights. Total grip strength was measured with a Jamar hand dynamometer. Leg power (vertical jump) was measured with a Vertec. Rotational power was measured with a Sports Pro radar gun as players performed a 2.7 kg medicine ball side toss. RESULTS: Significant increases (p < 0.05) in 1RM parallel squat, 1RM bench press, and leg power occurred after 8 wk of training for both groups. Significant increases in bat velocity were found only for group 2. CONCLUSIONS: The implementation of an over-weighted (7 oz) medicine ball training program at a 2:1 ratio (heavy and standard) did not increase TV during the preseason when players were throwing daily at practice. PRACTICAL APPLICATION: Implementing a supplemental over-weighted (7 oz) medicine ball program did not have any greater training effect than throwing a standard 5 oz baseball during the preseason. Therefore, it is not recommended to use this type of training during the preseason since no improvements were reported. Previous research has demonstrated improvements in TV during the off-season when athletes are not practicing and throwing. Although not the main focus of this research project, bat velocity significantly increased 5.3% for group 2. Group 1 also had an increase in bat velocity of 4.0%, but due to the high standard deviation, post-data were not significantly different than pre-data. These increases are similar to previous research that used similar participants and stepwise resistance training programs.
Kinesiology, Louisiana Tech University, Ruston, LA