| Fuel oxidation in relation to walking speed: influence of gradient and external load. | |
| | |
MedLine Citation:
|
PMID: 20535618 Owner: NLM Status: In-Process |
Abstract/OtherAbstract:
|
People intuitively walk at a speed that minimizes energy cost per meter. Therefore, the selective advantages of energetic efficiency are thought to drive individuals' preferred walking speed (PWS). This presumption disregards fuel partitioning, which may, in fact, be significant due to the disparate sizes of the carbohydrate (CHO) and fat reservoirs, coupled with the necessity of CHO for high intensity exercise. Potentially, PWS may reflect CHO conservation more than energetic efficiency per se. This study was designed to determine if PWS over a variety of conditions conforms to the CHO sparing hypothesis. Six subjects walked on a treadmill at five speeds: their PWS and speeds 0.45 and 0.22 m/s below and above PWS, under loads of 0, 10, and 20% of body weight, as well as at grades of -6.25, 0 and +6.25%. Oxygen consumption, carbon dioxide production and respiratory exchange ratio were measured over each 10 min bout to calculate total energy, CHO and fat usage. The subjects' mean (±SD) unloaded, level PWS was 1.32 ± 0.11 m/s. PWS was reduced by the 20% load and uphill grade, but not affected by the 10% load or downhill grade. Carbohydrate provided ≥50% of required energy in all conditions. The CHO oxidation rate was related to speed such that the gain was greater at speeds above than below the PWS; however, differences in CHO oxidation between conditions did not correspond to differences in PWS. We conclude that CHO sparing is not the primary determinant of PWS during externally loaded or grade walking. |
| | |
Authors:
|
Pauline L Entin; Colleen Gest; Susan Trancik; J Richard Coast |
Related Documents
:
|
17065338 - Pdh-e1alpha dephosphorylation and activation in human skeletal muscle during exercise: ... 15692328 - Carbohydrate feedings during team sport exercise preserve physical and cns function. 2262228 - Changes in selected blood measures during repeated days of intense training and carbohy... 14967868 - Effect of pre-exercise carbohydrate ingestion on plasma cytokine, stress hormone, and n... 19171808 - Effects of exercise modality on insulin resistance and functional limitation in older a... 22474468 - Differential expression of caveolins and myosin heavy chains in response to forced exer... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2010-06-10 |
Journal Detail:
|
Title: European journal of applied physiology Volume: 110 ISSN: 1439-6327 ISO Abbreviation: Eur. J. Appl. Physiol. Publication Date: 2010 Oct |
Date Detail:
|
Created Date: 2010-09-27 Completed Date: - Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 100954790 Medline TA: Eur J Appl Physiol Country: Germany |
Other Details:
|
Languages: eng Pagination: 515-21 Citation Subset: IM |
Affiliation:
|
SA Rasmussen Exercise Physiology Laboratory, Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA. Pauline.entin@nau.edu |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Retraction: prediction of maximal oxygen uptake from ratings of perceived exertion and heart rate du...
Next Document: Hydrogen sulfide degradation characteristics of Bordetella sp. Sulf-8 in a biotrickling filter.