BACKGROUND: In an effort to improve overhand throw velocity in baseball pitchers, weighted implement training, which utilizes balls that are heavier or lighter than a competition ball, have been employed. Weighted ball programs have previously been used in baseball pitchers ranging from high school to professional with varying ball weights with mixed results (Straub, 1966; Brose and Hanson, 1967; DeRenne, 1985; DeRenne, 1990; van den Tillaar and Ettema, 2011). PURPOSE: To determine the effect of a commercially available weighted ball program on the throwing velocity of collegiate baseball pitchers over the course of an off-season. METHODS: This retrospective study examined pitch velocity for 56 varsity collegiate baseball pitchers at the University of Mississippi between 2012-2015. The weighted implement (WI) group (n=35) used weighted implement training in addition to normal throwing activities throughout the off-season while the normal throwing (NT) group (n=21) participated in normal throwing activities only. The WI group used baseballs that were 20% overweight (6 ounces), 20% underweight (4 ounces), and regulation weight (5 ounces) while the NT group used only the regulation weight baseball. A repeated measures ANOVA was conducted. Statistical significance was set at p?0.05. RESULTS: Pitch velocity did not significantly increase from the beginning of the off-season to the end of the off-season (p=0.071) for either group and there was no significant difference between the two groups (p=0.271). CONCLUSION: In varsity collegiate pitchers currently involved in general and sport specific training, the current weighted implement throwing program is no more effective than a normal throwing protocol
