This dissertation reports the results of multiple quantitative investigations looking at the effect of using a dynamic moment of inertia bat prototype. This dissertation includes four (4) experimental research projects. The four (4) experimental research projects look at different ways to measure the efficacy of a dynamic moment of inertia bat to improve swing speed in baseball and softball. The findings suggest that a dynamic moment of inertia bat can be used as an effective warm-up tool and an effective training tool to improve bat swing speed in competitive baseball and softball players. The findings suggest that a dynamic moment of inertia bat is superior to a weighted bat as a warm-up tool because it negates the kinesthetic illusion. When athletes combine strength training and swing training using a dynamic moment of inertia bat over a 6-week training period it can lead to a significant improvement in bat swing speed that is superior to the improvement following a normal warm-up. The last experiment confirmed that using the dynamic moment of inertia bat can replicate a high-intensity warm-up and be effective as a warm-up tool. Baseball and softball players should consider using a dynamic moment of inertia to improve their bat swing speed during their training and as an on-deck warm-up tool before their at-bat performance.