Skiing economy and kinematic during a field double poling roller skiing among novice and experienced cross-country skiers.
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ABSTRACT:
SUBMITTER: Zhu Y
PROVIDER: S-EPMC10963750 | biostudies-literature | 2024 Mar
REPOSITORIES: biostudies-literature
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Skiing economy and kinematic during a field double poling roller skiing among novice and experienced cross-country skiers.
Zhu Yang Y Wang Zhiqiang Z Li Ruoyang R Li Yanyan Y Bai Peng P Gao Weifeng W Zhong Yaping Y
Scientific reports 20240325 1
To assess the skiing economy (SE) and kinematics during double poling (DP) roller skiing between two groups of skiers in a field setting. Five experienced and five novice male skiers performed a SE<sub>DP</sub> test at 16 km∙h<sup>-1</sup> on an outdoor athletics track. Gas exchange parameters were measured to determine SE<sub>DP</sub>. A two-dimensional video was filmed to measure the kinematics variables. Experienced skiers exhibited a 21% lower oxygen cost than novice skiers (p = 0.016) in DP ...[more]
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| S-EPMC8384222 | biostudies-literature
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| S-EPMC8473922 | biostudies-literature
Project description:ObjectivesWe investigated sex-based differences in speed, sub-technique selection, and kinematic patterns during low- (LIT) and high-intensity training (HIT) for classical cross-country (XC) skiing across varying terrain.MethodsSix male and six female elite XC skiers with an approximately 15% differences in VO2max (men: 68.9±2.9 mL·min-1·kg-1, women: 60.1±3.3 mL·min-1·kg-1) were monitored using a multi-sensor system to collect time-synchronised data of heart rate, speed, and multiple tri-axial inertial measurements units while XC skiing on a 5-km competition track.ResultsMen skied 21% faster than women during HIT (5.9±0.3 m·s-1 vs. 4.9±0.2 m·s-1, P < .001), with the greatest difference (26%) while skiing on flat terrain, whereas skiing speed did not significantly differ between men and women during LIT. At similar instructed intensity and rating of perceived effort, women exhibited significantly higher relative heart rate (85±2% vs. 71±3% of maximum) and blood lactate levels (4.0±1.3 vs. 1.2±0.2 mmol/L) during LIT (all P < .001) than men, whereas physiological responses did generally not differ between the sexes during HIT. During both intensities and among both sexes, double poling (DP) was the sub-technique most used relative to distance, followed by miscellaneous sub-techniques (MISC), diagonal stride (DIA), kick double poling (DK) and herringbone (HRB). In relation to distance women used DIA more than men during LIT (22% vs. 17%, P = .009) and HIT (23% vs. 12%, P = .001), whereas men used MISC, including tucking and turning, more than women during LIT (39% vs. 25%, P = .017) and HIT (41% vs. 30%, P = .064). In particular, men used DP more than women while skiing the uphill sections during both LIT (24% vs. 11%, P = .015) and HIT (39% vs. 13%, P = .002).ConclusionsOur findings provide novel insights into sex-based differences in speed, sub-technique selection, and kinematic patterns during LIT and HIT for classical skiing.
| S-EPMC6237352 | biostudies-literature
Project description:ObjectivesThe purpose of this study was to investigate the effect of different incline-speed combinations, at equal external power outputs, on the mechanics and energetics of the double-poling (DP) technique in cross-country skiing.MethodsFourteen elite male cross-country skiers performed treadmill DP on roller-skis at low, moderate, and high mean external power outputs (Pmean) up a shallow incline (5%, INC5), at which DP is preferred, and up a steep incline (12%, INC12), at which DP is not preferred. Speed was set to produce equal Pmean at both inclines. From recorded kinematics and dynamics, arm power (Parm) and trunk+leg power (PT+L) were derived, as were pole propulsion power (Ppole) and body mechanical energy perpendicular to the treadmill surface (Ebody⊥).ResultsOver a locomotion cycle, the arms contributed 63% to Pmean at INC5 but surprisingly only 54% at INC12 (P<0.001), with no effect of Pmean (P = 0.312). Thus, the trunk and legs contributed substantially to Pmean both at INC5 (37%) and INC12 (46%). At both inclines, PT+L generation during the swing phase increased approximately linearly with Pmean, which increased Ebody⊥. Within the poling phase, ~30-35% of the body energy which was developed during the preceding swing phase was transferred into propulsive pole power on both inclines. At INC5, the amount of negative PT+L during the poling phase was larger than at INC12, and this difference increased with Pmean.ConclusionsThe considerable larger amount of negative PT+L during poling at INC5 than at INC12 indicate that the legs and trunk generate more power than 'necessary' during the swing phase and thus must absorb more energy during the poling phase. This larger surplus of PT+L at INC5 seems necessary for positioning the body and poles so that high Parm generation can occur in a short time. At INC12, less Parm is generated, probably due to less advantageous working conditions for the arms, related to body and pole positioning. These incline differences seem linked to shorter swing and longer poling times during steep uphill DP, which are due to the increased influence of gravity and slower speed at steep inclines.
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