Anthropometric traits and physical performance of amateur rugby players within specific playing positions

BACKGROUND: This study examined the differences in physical and anthropometric traits between specific playing positions (i.e., forwards: front row, second row, back row; backs: half backs, centers, wings/fullbacks) in amateur rugby players and analyzed the magnitude of correlations among jump, sprint, and strength measures in forwards and backs. METHOD: Sixty-four male rugby players were assessed in anthropometrics, a variety of vertical jumps, 10- and 30-m sprint, and strength tests (i.e., squat and bench press). RESULTS: Front row forwards (F-FR) demonstrated significantly higher body mass (BM) than second row (F-SR) and back row (F-BR) (107.4 +/- 12.8, 99.1 +/- 9.9 and 91.6 +/- 7.6 kg respectively; p < 0.001). F-FR showed greater absolute strength in bench press and squat, although no differences were found in relative strength. Regarding the differences in jump performance, F-BR and F-SR showed significantly (p < 0.05) and significant to non-significant (p = 0.042-0.078, ES = 0.90-1.55) higher jumps in all tasks compared to F-FR. Moreover, F-BR demonstrated lower sprint times and greater maximum sprinting speed (MSS) than F-FR (p < 0.01). For the backs, centers (B-CEN) were significantly heavier (p < 0.05) and exhibited a non-significantly moderate larger sprint momentum (p = 0.068, ES = 0.75) compared to half backs (BHB). MSS values were small to moderately greater in favor of wings/fullbacks [B-WFB] (p = 0.188-0.059, ES = 0.50-0.71). Finally, statistically significant correlations were found between drop jump (flight time) and jump height across all jump tasks, sprint times and speed for both forwards (r = 0.541 to 0.996, p < 0.001) and backs (r = 0.422 to 0.995, p < 0.05). CONCLUSIONS: In conclusion, F-FR demonstrated significant, small to very large differences, when compared to their specific peers, whereas the backs were more similar. Additionally, our results indicated moderate to strong associations between explosive tasks such as sprinting and jumping in both playing positions.