Cargando…
Economical Speed and Energetically Optimal Transition Speed Evaluated by Gross and Net Oxygen Cost of Transport at Different Gradients
The oxygen cost of transport per unit distance (CoT; mL·kg(-1)·km(-1)) shows a U-shaped curve as a function of walking speed (v), which includes a particular walking speed minimizing the CoT, so called economical speed (ES). The CoT-v relationship in running is approximately linear. These distinctiv...
Autores principales: | , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2015
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4575035/ https://www.ncbi.nlm.nih.gov/pubmed/26383249 http://dx.doi.org/10.1371/journal.pone.0138154 |
_version_ | 1782390714262355968 |
---|---|
author | Abe, Daijiro Fukuoka, Yoshiyuki Horiuchi, Masahiro |
author_facet | Abe, Daijiro Fukuoka, Yoshiyuki Horiuchi, Masahiro |
author_sort | Abe, Daijiro |
collection | PubMed |
description | The oxygen cost of transport per unit distance (CoT; mL·kg(-1)·km(-1)) shows a U-shaped curve as a function of walking speed (v), which includes a particular walking speed minimizing the CoT, so called economical speed (ES). The CoT-v relationship in running is approximately linear. These distinctive walking and running CoT-v relationships give an intersection between U-shaped and linear CoT relationships, termed the energetically optimal transition speed (EOTS). This study investigated the effects of subtracting the standing oxygen cost for calculating the CoT and its relevant effects on the ES and EOTS at the level and gradient slopes (±5%) in eleven male trained athletes. The percent effects of subtracting the standing oxygen cost (4.8 ± 0.4 mL·kg(-1)·min(-1)) on the CoT were significantly greater as the walking speed was slower, but it was not significant at faster running speeds over 9.4 km·h(-1). The percent effect was significantly dependent on the gradient (downhill > level > uphill, P < 0.001). The net ES (level 4.09 ± 0.31, uphill 4.22 ± 0.37, and downhill 4.16 ± 0.44 km·h(-1)) was approximately 20% slower than the gross ES (level 5.15 ± 0.18, uphill 5.27 ± 0.20, and downhill 5.37 ± 0.22 km·h(-1), P < 0.001). Both net and gross ES were not significantly dependent on the gradient. In contrast, the gross EOTS was slower than the net EOTS at the level (7.49 ± 0.32 vs. 7.63 ± 0.36 km·h(-1), P = 0.003) and downhill gradients (7.78 ± 0.33 vs. 8.01 ± 0.41 km·h(-1), P < 0.001), but not at the uphill gradient (7.55 ± 0.37 vs. 7.63 ± 0.51 km·h(-1), P = 0.080). Note that those percent differences were less than 2.9%. Given these results, a subtraction of the standing oxygen cost should be carefully considered depending on the purpose of each study. |
format | Online Article Text |
id | pubmed-4575035 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-45750352015-09-25 Economical Speed and Energetically Optimal Transition Speed Evaluated by Gross and Net Oxygen Cost of Transport at Different Gradients Abe, Daijiro Fukuoka, Yoshiyuki Horiuchi, Masahiro PLoS One Research Article The oxygen cost of transport per unit distance (CoT; mL·kg(-1)·km(-1)) shows a U-shaped curve as a function of walking speed (v), which includes a particular walking speed minimizing the CoT, so called economical speed (ES). The CoT-v relationship in running is approximately linear. These distinctive walking and running CoT-v relationships give an intersection between U-shaped and linear CoT relationships, termed the energetically optimal transition speed (EOTS). This study investigated the effects of subtracting the standing oxygen cost for calculating the CoT and its relevant effects on the ES and EOTS at the level and gradient slopes (±5%) in eleven male trained athletes. The percent effects of subtracting the standing oxygen cost (4.8 ± 0.4 mL·kg(-1)·min(-1)) on the CoT were significantly greater as the walking speed was slower, but it was not significant at faster running speeds over 9.4 km·h(-1). The percent effect was significantly dependent on the gradient (downhill > level > uphill, P < 0.001). The net ES (level 4.09 ± 0.31, uphill 4.22 ± 0.37, and downhill 4.16 ± 0.44 km·h(-1)) was approximately 20% slower than the gross ES (level 5.15 ± 0.18, uphill 5.27 ± 0.20, and downhill 5.37 ± 0.22 km·h(-1), P < 0.001). Both net and gross ES were not significantly dependent on the gradient. In contrast, the gross EOTS was slower than the net EOTS at the level (7.49 ± 0.32 vs. 7.63 ± 0.36 km·h(-1), P = 0.003) and downhill gradients (7.78 ± 0.33 vs. 8.01 ± 0.41 km·h(-1), P < 0.001), but not at the uphill gradient (7.55 ± 0.37 vs. 7.63 ± 0.51 km·h(-1), P = 0.080). Note that those percent differences were less than 2.9%. Given these results, a subtraction of the standing oxygen cost should be carefully considered depending on the purpose of each study. Public Library of Science 2015-09-18 /pmc/articles/PMC4575035/ /pubmed/26383249 http://dx.doi.org/10.1371/journal.pone.0138154 Text en © 2015 Abe et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited. |
spellingShingle | Research Article Abe, Daijiro Fukuoka, Yoshiyuki Horiuchi, Masahiro Economical Speed and Energetically Optimal Transition Speed Evaluated by Gross and Net Oxygen Cost of Transport at Different Gradients |
title | Economical Speed and Energetically Optimal Transition Speed Evaluated by Gross and Net Oxygen Cost of Transport at Different Gradients |
title_full | Economical Speed and Energetically Optimal Transition Speed Evaluated by Gross and Net Oxygen Cost of Transport at Different Gradients |
title_fullStr | Economical Speed and Energetically Optimal Transition Speed Evaluated by Gross and Net Oxygen Cost of Transport at Different Gradients |
title_full_unstemmed | Economical Speed and Energetically Optimal Transition Speed Evaluated by Gross and Net Oxygen Cost of Transport at Different Gradients |
title_short | Economical Speed and Energetically Optimal Transition Speed Evaluated by Gross and Net Oxygen Cost of Transport at Different Gradients |
title_sort | economical speed and energetically optimal transition speed evaluated by gross and net oxygen cost of transport at different gradients |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4575035/ https://www.ncbi.nlm.nih.gov/pubmed/26383249 http://dx.doi.org/10.1371/journal.pone.0138154 |
work_keys_str_mv | AT abedaijiro economicalspeedandenergeticallyoptimaltransitionspeedevaluatedbygrossandnetoxygencostoftransportatdifferentgradients AT fukuokayoshiyuki economicalspeedandenergeticallyoptimaltransitionspeedevaluatedbygrossandnetoxygencostoftransportatdifferentgradients AT horiuchimasahiro economicalspeedandenergeticallyoptimaltransitionspeedevaluatedbygrossandnetoxygencostoftransportatdifferentgradients |