Assessing Lower-Body Peak Power in Elite Rugby-Union Players

• Published in: Journal of strength and conditioning research Vol. 25; no. 6; pp. 1616 - 1621
• Main Authors: Argus, Christos K, Gill, Nicholas D, Keogh, Justin WL, Hopkins, Will G
• Format: Journal Article
• Language: English
• Published: United States National Strength and Conditioning Association 01.06.2011; Lippincott Williams & Wilkins Ovid Technologies
• Subjects: Adult; Athletes; Athletic Performance - physiology; Football - physiology; Human subjects; Humans; Load; Muscle Strength - physiology; Muscle, Skeletal - physiology; Resistance Training; Studies; Young Adult
• ISSN: 1064-8011; 1533-4287; 1533-4287
• DOI: 10.1519/JSC.0b013e3181ddfabc

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 (Pmax) may produce greater increases in peak power than other loads. Pmax for lower-body lifts can occur with no loading but whether Pmax can be increased further with negative loading is unclear. The purpose of this investigation was therefore to determine lower-body Pmax (jump squat) using a spectrum of loads. Box squat 1 repetition maximum (1RM) was measured in 18 elite rugby-union players. Pmax was then determined using loads of −28 to 60%1RM. Elastic bands were used to unload body weight for negative loads. Jump squat Pmax occurred with no loading (body weight8,880 ± 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.