Running Head: Scaling of Women's Rowing Performance by Body Size

Key Words: Power Function Ratios; Human Performance; Rowing; Body Size Adjustment; Allometric Scaling; Rowing Performance

Body size (stature and body mass) influences maximal rowing ergometer performance for 2500m. In the World Indoor Rowing Championships (WIRC), subjects compete in two weight classes; thus, some individuals close to the cutoff perform at a disadvantage because they are either too light or too heavy. The statistical technique of multivariate allometric scaling (MAS) creates a new score for each individual free of the confounding effect of one or more of the body size variables. In an analysis of 56 competitive female rowers from the 1995 WIRC, we used MAS to create stature (S) and body mass (BM) adjusted rowing performance scores based on time (T.Sa . BMb). MAS revealed that T.S0.54 BM0.18 adequately expressed T, free of the independent effects of S and BM. In addition, T.S served as a statistically correct (and feasible) expression of stature-adjusted race performance. Use of either scaling convention dramatically changed race results; a subject who initially placed nineteenth finished first, and a competitor who finished third moved to thirty-second place. Because S was the more potent body size-related determinant of WIRC performance (faster T, s), we recommend use of the T.S convention for women in future indoor rowing competitions. Scaling eliminates the need to compete in heavyweight or lightweight categories; instead, scaling enables analysis of individual differences in rowing performance without bias that favors taller and heavier competitors.