External loading does not change energy cost and mechanics of rollerski skating.
Details
Serval ID
serval:BIB_37637
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
External loading does not change energy cost and mechanics of rollerski skating.
Journal
European Journal of Applied Physiology and Occupational Physiology
ISSN
1439-6319
ISSN-L
0301-5548
Publication state
Published
Issued date
1998
Peer-reviewed
Oui
Volume
78
Number
3
Pages
276-282
Language
english
Abstract
The purpose of this study was to examine the effects of external loading on the energy cost and mechanics of roller ski skating. A group of 13 highly skilled male cross-country skiers roller skied at 19.0 ( SD 0.1) km x h(-1) without additional load and with loads of 6% and 12% body mass (mb). Oxygen uptake (VO2), knee and ankle joint kinematics, roller-ski electromyogram (EMG) of the vastus lateralis and gastrocnemius lateralis muscles, and roller ski velocity were recorded during the last 40 s of each 4-min period of roller skiing. One-way repeated measures ANOVA revealed that the VO2 expressed relative to total mass (mtot), joint kinetics, eccentric-to-concentric ratio of the integrated EMG, velocity changes within a cycle, and cycle rate did not change significantly with load. The subsequent analysis of the effect of load on each resistance opposing motion suggested that the power to sustain changes in translational kinetic energy, potential energy, and overcoming rolling resistance increased proportionately with the load. The lack of a significant change in VO2/mtot with external loading was associated with a lack of marked change in external mechanical power relative to mtot. The existence of an EMG signal during the eccentric phase prior to the thrust (concentric phase), as well as the lack of significant delay between the two phases, showed that a stretch-shortening cycle (SSC) occurs in roller ski skating. Taken together, the present results would suggest that external loading up to 12% mb does not increase storage and release of elastic energy of lower limb muscles during SSC in roller ski skating.
Keywords
Adult, Biomechanics, Electromyography, Energy Metabolism/physiology, Humans, Lactic Acid/blood, Male, Oxygen Consumption/physiology, Skating/physiology, Skiing/physiology
Pubmed
Web of science
Create date
19/11/2007 11:12
Last modification date
20/08/2019 14:25