https://revistaseug.ugr.es/index.php/IJRSS/issue/feedInternational Journal of Racket Sports Science2025-09-18T00:17:19+00:00David Cabello Manriqueinfo@journal.racketsportscience.orgOpen Journal Systems<p>The International Journal of Racket Sports Science is an open-access online journal that publishes unpublished research articles, reviews, and letters in all areas related to racket sports and sports science. The journal's primary objective is to provide a comprehensive and reliable source of information on the latest advances in this field, positioning itself as a key resource for researchers, practitioners, and students interested in the scientific study of racket sports.</p>https://revistaseug.ugr.es/index.php/IJRSS/article/view/34914Physical strength factors affecting the competitive level of Japanese male tennis players2025-09-16T17:05:11+00:00Nahoko Koyan-koya@daido-it.ac.jpTetsu Kitamuran-koya@daido-it.ac.jp<p>Technical skills are predominant factors in tennis, so players spend a significant amount of time on court technical training with a racket. Devoting the same time as on-court technical training to physical training without a racket is quite difficult. However, as the competition level increases, many players realize the importance of their physical strength and fitness. From the perspective that higher physical strength is required depending on the competition level, clarifying the extent of the difference between domestic and global levels will be a practically useful and developmental training indicator. Therefore, this study aimed to identify physical strength factors that serve as a guideline for competing internationally and examine physical strength indicators in 54 Japanese male tennis players. The players performed five physical strength tests (5-meter sprint, T-test, 505 agility test, vertical jump, and medicine ball throw (MBT)). Multiple regression analysis was performed, and a significant regression equation was extracted, with the MBT and T-test as independent variables, which could predict competitive rankings (Y=11032.87+845.34x<sub>1</sub> − 5768.43X<sub>2</sub> (x<sub>1</sub>: MBT, x<sub>2</sub>: T-test), F=17.67, p<0.001). The contribution rate of this equation was 41.9% (r=0.647); approximately 42% of competitive rankings could be explained by the MBT and T-test. The novel finding of this study is that for Japanese male tennis players to become world-class players, physical strength factors related to the MBT and T-test could be strengthened. Furthermore, these indicators could be used to identify talents among junior players.</p>2025-09-18T00:00:00+00:00Copyright (c) 2025 Nahoko Koya, Tetsu Kitamura