In winter sport of luging the first phases of the start are known to have a leading role for the successful start performance (Lembert et al., 2011). Kinetics of this highly demanding sport is seldom evaluated. The aim of this study was to assess power output of lugers during the initial start phases, as a possible performance predictor. Methods: Experienced lugers (4 female and 4 male) gave an informed consent for their routine training start attempts on the ramp to be videotaped and analysed. For each athlete the best out of 3 attempts was processed. Average power output during the start spurt phase (Ps), average power to reach maximal positive velocity in the spurt phase (Pmax), and average power to reach maximal backward velocity (Pback) were calculated as in (Bezodis et al., 2008). Sled velocity was estimated from 100 fps video records using Simi Motion analysis software. 2 start interval times - time to clear 3 m (t1) and 15 m (t2) distance on the slope - were used as performance criteria. Results: For all athletes Pmax had the largest values among all power parameters; it ranged from 3104 to 3875 W in male group, and from 1584 to 2458 W in female group. Other power parameters showed larger relative differences within groups: Ps ranged from 334 to 867 in male, and from 187 to 394 W in female group; Pback 505 to 1293 for male, and 295 to 600 W in female group. From all measured variables only maximal velocity (Vmax) during the start spurt correlated with performance criteria (in male group only). Discussion: From the preliminary study all calculated power parameters appear to be poor performance predictors. This is also true for values normalized to body mass. Vmax correlation with start time in male group is in accordance with Platzer et al. (2009) data; however, in female group correlation was not obvious. Average Pmax values normalized to body mass for both groups are comparable to values in snatch pull in weightlifting according to previously published data; absolute values tend to exceed the ones reported for weightlifters (Garhanner, 1991; Zebas et al., 2000). Given an emphasis is put on strength training in luging, power output assessment might provide additional information for coaches and athletes. Nevertheless, using power output as a performance predictor is not justified so far.
© Copyright 2012 17th Annual Congress of the European College of Sport Science (ECSS), Bruges, 4. -7. July 2012. Veröffentlicht von Vrije Universiteit Brussel. Alle Rechte vorbehalten.