title: Scaling of upper-body power output to predict time-trial roller skiing performance.
abstract: The purpose of the present study was to establish the most appropriate allometric model to predict mean skiing speed during a double-poling roller skiing time-trial using scaling of upper-body power output. Forty-five Swedish junior cross-country skiers (27 men and 18 women) of national and international standard were examined. The skiers, who had a body mass (m) of 69.3 ± 8.0 kg (mean ± s), completed a 120-s double-poling test on a ski ergometer to determine their mean upper-body power output (W). Performance data were subsequently obtained from a 2-km time-trial, using the double-poling technique, to establish mean roller skiing speed. A proportional allometric model was used to predict skiing speed. The optimal model was found to be: Skiing speed = 1.057 · W (0.556) · m (-0.315), which explained 58.8% of the variance in mean skiing speed (P < 0.001). The 95% confidence intervals for the scaling factors ranged from 0.391 to 0.721 for W and from -0.626 to -0.004 for m. The results in this study suggest that allometric scaling of upper-body power output is preferable for the prediction of performance of junior cross-country skiers rather than absolute expression or simple ratio-standard scaling of upper-body power output.
authors.affiliation: Dalarna University, Health and Social Sciences, Falun, Sweden. tca@du.se
authors.forename: Tomas
authors.initials: T
authors.lastname: Carlsson
authors.forename: Magnus
authors.initials: M
authors.lastname: Carlsson
authors.forename: Daniel
authors.initials: D
authors.lastname: Hammarström
authors.forename: Christer
authors.initials: C
authors.lastname: Malm
authors.forename: Michail
authors.initials: M
authors.lastname: Tonkonogi
mesh_terms: D000293:Adolescent; D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D016552:Ergometry; D005260:Female; D006801:Humans; D008297:Male; D008954:Models, Biological; D009068:Movement / Q000502:physiology; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D012865:Skiing; D013177:Sports / Q000502:physiology*; D013647:Task Performance and Analysis; D034941:Upper Extremity; D055815:Young Adult