STRENGTH AND POWER CHARACTERISTICS IN ENGLISH ELITE RUGBY LEAGUE PLAYERS

Comfort, P, Graham-Smith, P, Matthews, MJ, and Bamber, C. Strength and power characteristics in English elite rugby league players. J Strength Cond Res 25(5): 1374-1384, 2011-The aim of this article is to present data on the strength and power characteristics of forwards and backs in a squad of elite English rugby league players and compare these findings to previously published literature from Australia. Participants were elite English rugby league players (n = 18; height 184.16 +/- 5.76 cm; body mass 96.87 +/- 10.92 kg, age 21.67 +/- 4.10 years) who were all regular first team players for an English Superleague club. Testing included 5-, 10-, 20-m sprint times, agility, vertical jump, 40-kg squat jump, isometric squat, concentric and eccentric isokinetic knee flexion and extension. Independent t-tests were performed to compare results between forwards and backs, with paired samples t-tests used to compare bilateral differences from isokinetic assessments and agility tests. Forwards demonstrated significantly (p < 0.05) greater body mass (102.15 +/- 7.5 kg), height (186.30 +/- 5.47 cm), power during the 40-kg jump squat (2,106 +/- 421 W), isometric force (3,122 +/- 611 N) and peak torque during left concentric isokinetic knee extension (296.1 +/- 54.2 N.m) compared to the backs (86.30 +/- 8.97 kg; 179.87 +/- 3.72 cm; 1,709 +/- 286W; 2,927 +/- 607 N; 241.7 +/- 35.2 N.m, respectively). However, no significant differences (p. 0.05) were noted between forwards and backs during right concentric isokinetic knee extension (274.8 +/- 37.7 and 246.8 +/- 25.8 N.m), concentric isokinetic knee flexion for both left (158.8 +/- 28.6 and 141.0 +/- 22.7 N.m) and right legs (155.3 +/- 22.9 and 128.0 +/- 23.9 N.m), eccentric isokinetic knee flexion and extension, hamstring quadriceps ratios, or vertical jump (37.25 +/- 4.35 and 40.33 +/- 6.38 cm). In comparison, relative measures demonstrated that backs performed significantly better compared to the forwards during the 40-kg jump squat (20.71 +/- 5.15 and 19.91 +/- 3.91 W.kg(-1)) and the isometric squat (34.32 +/- 7.9 and 30.65 +/- 5.34 N.kg(-1)). Bilateral comparisons revealed no significant differences (p. 0.05) between left and right leg performances in the agility test (3.26 +/- 0.18 and 3.24 +/- 0.18 seconds), or between left (0.7 +/- 0.10) and right (0.71 +/- 0.17) leg eccentric hamstring concentric quadriceps ratios. The results demonstrate that absolute strength and power measures are generally higher in forwards compared to in backs; however, when body mass is taken into account and relative measures compared, the backs outperform the forwards.