Physical demands of representative match play in adolescent rugby union

The purpose of this study was to quantify the physical demands of representative adolescent rugby union match-play and investigate the difference between playing positions and age groups. Players (n=112) were classified into 6 groups by playing position (forwards and backs) and age group (U16, U18, U20). The physical demands were measured using microsensor-based technology and analysed using magnitude based inferences to assess practical importance. Backs had a greater relative distance (except U16s) and a greater high-speed running distance per minute than forwards, with the magnitude of difference between the positions becoming larger in older age groups. Forwards had higher values of PlayerLoadTM per minute (accumulated accelerations from the three axes of movement) and PlayerLoadTM slow per minute (accumulated accelerations from the three axes of movement where velocity is <2 m.s-1) than backs at all age groups. Relative distance, low- and high-speed running per minute all had a trend to be lower in older age groups for both positions. PlayerLoadTM per minute was greater in U18 than U16 and U20 for both positions. PlayerLoadTM slow per minute was greater for older age groups besides the U18 and U20 comparisons, which were unclear. The contrasts in physical demands experienced by different positions reinforce the need for greater exposure to sprinting and collision based activity for backs and forwards, respectively. Given PlayerLoadTM metrics peak at U18 and locomotor demands seem to be lower in older ages, the demands of representative adolescent rugby union do not seem to be greater at U20 as expected.