Association between the phase angle and muscle-tendon complex function in Japanese athletes: a comparative study.

[Purpose] In this study, we investigated the association between the phase angle and the muscle-tendon complex in Japanese athletes and the effects of aging on this association. [Participants and Methods] The study included 61 adult male high school soccer players. Body composition was evaluated using an analyzer, and grip strength and rebound jump index were measured to evaluate muscle-tendon complex function. Study participants were categorized into two groups, and statistical analyses were performed for intergroup comparison of outcomes and to determine the correlation between the phase angle and muscle-tendon complex function. [Results] We observed significant intergroup differences in the phase angle, total body muscle mass, grip strength, and rebound jump index. Additionally, we observed a significant positive correlation between the phase angle and grip strength in adult soccer players. [Conclusion] Our results showed a correlation between the phase angle and muscle-tendon complex function in mature adult athletes but not in high school athletes. These findings suggest that the phase angle may serve as an indicator of muscle quality and overall physical condition in adult athletes. Further research is warranted to investigate the association between the phase angle and other performance measures to gain a better understanding of soccer players' athletic abilities.