Optimal slopes and speeds in uphill ski mountaineering: a field study.

Details

Serval ID
serval:BIB_42CB5E70E93C
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Optimal slopes and speeds in uphill ski mountaineering: a field study.
Journal
European journal of applied physiology
Author(s)
Praz C., Fasel B., Vuistiner P., Aminian K., Kayser B.
ISSN
1439-6327 (Electronic)
ISSN-L
1439-6319
Publication state
Published
Issued date
10/2016
Peer-reviewed
Oui
Volume
116
Number
10
Pages
2017-2024
Language
english
Notes
Publication types: Journal Article
Publication Status: ppublish
Abstract
The aim of this study is to describe the effects of speed and gradient during uphill ski mountaineering on energy expenditure, to relate any changes to changes in stride characteristics, and to determine an optimal gradient and speed allowing minimization of energy expenditure.
11 subjects were tested on snowy trails using their mountaineering skis (fitted with skins), boots and poles, at three gradients (7, 11 and 33 %) at 80 % of maximum heart rate (HRmax), and at 11 % also at 90 and 100 % of HRmax. Energy expenditure was calculated by indirect calorimetry to derive energy cost of locomotion (EC), vertical energy cost (ECvert) and mechanical efficiency, while stride length, stride frequency, relative and absolute thrust phase duration, and slope gradient were measured with an inertial sensor-based system.
At 11 % there was no change with speed in EC, ECvert and mechanical efficiency, while stride length and frequency increased and absolute thrust phase duration decreased. There was an effect of gradient on EC, ECvert and mechanical efficiency, while speed, stride length and stride frequency decreased and absolute and relative thrust phase duration increased. The most economical gradient (lowest ECvert) was the steepest one.
During ski mountaineering uphill at shallow gradient (11 %), EC, ECvert and mechanical efficiency do not vary with speed, while at steeper gradient (33 %) economy is improved. It follows that to minimize energy expenditure and optimize performance to reach a place located at a higher altitude, an athlete should choose a steep gradient, if he/she is able to maintain a sufficient speed.

Keywords
Adult, Athletic Performance/physiology, Ecosystem, Energy Metabolism/physiology, Humans, Male, Mountaineering/physiology, Oxygen Consumption/physiology, Physical Exertion/physiology, Psychomotor Performance/physiology, Skiing/physiology
Pubmed
Create date
16/09/2016 17:47
Last modification date
20/08/2019 13:45
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