The relationship between ball mass and throw distance: Implications for coaching practice

In training for many sports, balls of different masses are thrown. This study examined how ball mass influences distance thrown. Based on geometric scaling principles a relationship was derived between ball mass and throw distance: throw distance was inversely proportional to ball mass. This relationship was tested in two ways. The first approach was using athlete shot put throw distances with different shot masses, and hammer throws performed with different mass hammers. These experimental data were better represented by the non-linear relationship, derived from geometric scaling principles, than assuming a simple linear relationship. The second approach was to use a simulation model to predict throw distance for balls of different masses. The model contained realistic segmental inertial properties, activation dynamics, moment-joint angle properties, and moment-joint angular velocity properties. The non-linear relationship provided a better fit to the results of the simulations compared with a linear model. The experimental and modeling results support the theoretical relationship derived between distance thrown and ball mass. The relationship has utility for coaches monitoring and planning the training of athletes which incorporates throwing different mass balls.