An applied model for using variability in practice.

We explore the problem of variability of practice from an applied perspective. Different types of variability, i.e., numerosity, heterogeneity, situational diversity, and scheduling are presented from the motor learning perspective, including theories, models, and concepts. We present the implications of applying variability into practice, the advantages, and problems arising while varying the practice. Finally, we propose a pragmatic model of applying variability in motor practice to assist coaches in designing effective training programs. Answers to three simple questions guide coaches to different methods of introducing variability in the practice. We present also key principles, coaches have to follow, in order to apply variability appropriately. [ABSTRACT FROM AUTHOR]