A comparison of physiological and anthropometric characteristics among playing positions in junior rugby league players

Objectives: To compare the physiological and anthropometric characteristics of specific playing positions and positional playing groups in junior rugby league players. Methods: Two hundred and forty junior rugby league players underwent measurements of standard anthropometry ( body mass, height, sum of four skinfolds), muscular power ( vertical jump), speed ( 10, 20, and 40 m sprint), agility ( L run), and estimated maximal aerobic power (multi-stage fitness test) during the competitive phase of the season, after players had obtained a degree of match fitness. Results: Props were significantly ( p< 0.05) taller, heavier, and had greater skinfold thickness than all other positions. The halfback and centre positions were faster than props over 40 m. Halfbacks had significantly ( p< 0.05) greater estimated maximal aerobic power than props. When data were analysed according to positional similarities, it was found that the props positional group had lower 20 and 40 m speed, agility, and estimated maximal aerobic power than the hookers and halves and outside backs positional groups. Differences in the physiological and anthropometric characteristics of other individual playing positions and positional playing groups were uncommon. Conclusions: The results of this study demonstrate that few physiological and anthropometric differences exist among individual playing positions in junior rugby league players, although props are taller, heavier, have greater skinfold thickness, lower 20 and 40 m speed, agility, and estimated maximal aerobic power than other positional playing groups. These findings provide normative data and realistic performance standards for junior rugby league players competing in specific individual positions and positional playing groups.