ASSESSING LOWER-BODY PEAK POWER IN ELITE RUGBY-UNION PLAYERS

Argus, CK, Gill, ND, Keogh, JWL, and Hopkins, WG. Assessing lower-body peak power in elite rugby-union players. J Strength Cond Res 25(6): 1616-1621, 2011-Resistance training at the load that maximizes peak power (P(max)) may produce greater increases in peak power than other loads. P(max) for lower-body lifts can occur with no loading but whether P(max) can be increased further with negative loading is unclear. The purpose of this investigation was therefore to determine lower-body P(max) (jump squat) using a spectrum of loads. Box squat 1 repetition maximum (1RM) was measured in 18 elite rugby-union players. P(max) was then determined using loads of 228 to 60% 1RM. Elastic bands were used to unload body weight for negative loads. Jump squat P(max) occurred with no loading (body weight: 8,880 +/- 2,186 W) in all but 2 subjects. There was a discontinuity in the power-load relationship for the jump squat, possibly because of the increased countermovement in the body weight jump. The self-selected depth (dip) before the propulsive phase of the jump was greater by 24 +/- 11 to 40 +/- 16% (moderate to large effect size) than all positive loads. These findings highlight methodological issues that need to be taken into consideration when comparing power outputs of loaded and unloaded jumps.