Content area
Full Text
ABSTRACT. Cleather, D.J. Adjusting powerlifting performances for differences in body mass. J. Strength Cond. Res. 20(2):412-421. 2006.-It has been established that, in the sports of Olympic weightlifting (OL) and powerlifting (PL), the relationship between lifting performance and body mass is not linear. This relationship has been frequently studied in OL, but the literature on PL is less extensive. In this study, PL performance and body mass, for both men and women, was examined by using data from the International Powerlifting Federation World Championships during 1995-2004. Nonlinear regression was used to apply 7 models (including allometric, polynomial, and power models) to the data. The results of this study indicate that the relationship between PL performance and body mass can be best modeled by the equation y = a - bx^sup -c^, where y is the weight lifted (in kg) in the squat, bench press, or deadlift, x is the body mass of the lifter (in kg), and a, b, and c are constants. The constants a, b, and c are determined by the type of lift (squat, bench press, or deadlift) and the gender of the lifter and were obtained from the regression analysis. Inspection of the plots of raw residuals (actual performance minus predicted performance) vs. body mass revealed no body mass bias to this formula in contrast to research into other handicapping formulas. This study supports previous research that found a bias toward lifters in the intermediate weight categories in allometric fits to PL data.
KEY WORDS. body weight scaling, allometric modeling regression
INTRODUCTION
Although the simplicity of this model is attractive, it is based on a number of assumptions. Probably the most notable of these is the assumption that the relationship between lifting performance and strength is linear. However, there are a number of neural, biomechanical, and physiological factors that may confound this relationship. For example, the distance of muscle insertion points from the pivot points of articular joints or an athlete's ability to recruit the greatest percentage of motor units will affect the display of strength. Other factors may also influence lifting performance. These include technical skill, training background, genetic predisposition, nutritional status, body composition, optimal body size, and motivation of the lifter. Because any one (or all) of these factors...