Physical Characteristics That Differentiate Playing Levels of Male Rugby Union Players: A Systematic Review.

Payne, LKD, Varley, MC, Driller, MW, and James, LP. Physical characteristics that differentiate playing levels of male rugby union players: a systematic review. J Strength Cond Res 39(9): 1013-1022, 2025-The distinct strength and speed characteristics differentiating Rugby Union athletes by playing level remain unclear, as do their associations with game performance indicators. This review systematically evaluated physical characteristics of adult male Rugby Union athletes across professional, semi-professional, and amateur levels. Five databases (PubMed, CINAHL, SPORTDiscus, Web of Science, Scopus) were searched, yielding 54 eligible studies. Higher-level athletes consistently demonstrated superior heavy dynamic strength (5/5 studies) and fast dynamic strength (3/3 studies). Results were mixed for acceleration (4/5 studies) and maximal sprint speed (3/6 studies), whereas limited evidence supported greater maximal isometric strength (1/1 study) and reactive strength (1/1 study). Explosive strength remains unexplored. Significant associations were observed between strength and speed characteristics and game performance indicators, except for explosive strength because of a lack of investigation. Heavy and fast dynamic strength emerged as key differentiators of playing levels and correlated strongly with game performance metrics. In contrast, findings for sprint speed and acceleration were inconsistent. This review highlights critical gaps in research, particularly regarding maximal isometric, explosive, and reactive strength, providing insights for future studies and practical applications in Rugby Union training.