Assessing the variation in the load that produces maximal upper-body power.

Substantial variation in the load that produces maximal power has been reported. It has been suggested that the variation observed may be due to differences in subjects' physical characteristics. Therefore, the aim of this study was to determine the extent in which anthropometric measures correlate with the load that produces maximal power. Anthropometric measures (upper-arm length, forearm length, total arm length, and upper-arm girth) and bench press strength were assessed in 26 professional rugby union players. Peak power was then determined in the bench press throw exercise using loads of 20-60% of one repetition maximum (1RM) in the bench press exercise. Maximal power occurred at 30 ± 14% 1RM (mean ± SD). Upper-arm length had the highest correlation with the load maximizing power: -0.61 (90% confidence limits -0.35 to -0.78), implying loads of 22 vs. 38% 1RM maximize power for players with typically long vs. short upper-arm length. Correlations for forearm length, total arm length, and upper-arm girth to the load that maximized power were -0.29 (0.04 to -0.57), -0.56 (-0.28 to -0.75), and -0.29 (0.04 to -0.57), respectively. The relationship between 1RM and the load that produced maximal power was r = -0.23 (0.10 to -0.52). The between-subject variation in the load that maximized power observed (SD = ±14% of 1RM) may have been due to differences in anthropometric characteristics, and absolute strength and power outputs. Indeed, athletes with longer limbs and larger girths and greater maximal strength and power outputs used a lower percentage of 1RM loads to achieve maximum power. Therefore, we recommend individual assessment of the load that maximizes power output.