The purpose of this study is to investigate the importance of the training of core muscles to bowler-athletes. Literature review is utilized to compile and discuss findings in relevant literature and books on the training of core muscles and bowling sports. As indicated in literature review, the training of core muscles can significantly improve muscle mass and endurance of body parts of athletes as well as body stability. During the bowling process, muscle groups in use are those that can be improved by the training of core muscles; especially, from ball holding, walking, and swinging to release the ball, great benefits of stable core muscles in the development of delivery techniques are observed. Thus, this study proposes the inclusion of the course of the training of core muscles to improve performance of bowler-athletes.