The relationships between maximal oxygen consumption (VO2max), mitochondrial function and running economy were investigated in a population of twenty-one endurance trained males and females (range=18-54 yrs). The purposes of this study were: 1) to determine whether mitochondrial oxidative capacity, as defined by the maximal activities of citrate synthase (CS), cytochrome c oxidase (COX), and beta-hydroxyacyl-CoA dehydrogenase (BHAD), is a significant determinant of maximal oxygen consumption in endurance trained men and women, and 2) to observe the relationship between maximal oxygen uptake and running economy in the same population. Muscle biopsy samples were taken from the vastus lateralis prior to a 90-minute bout of submaximal running (65% VO2max) from which running economy was assessed. Running economy was observed to significantly negatively correlate with VO2max, expressed in either absolute or relative values: L/min (r = -.506), ml/kg body mass/min (r = -.703) and ml/kg FFM/min (r = -.700). Data also show that maximal COX activity was significantly related to VO2max, L/min (r = .789). In addition, non-significant positive correlations were apparent between both CS and COX activity and all other expressions of VO2max (r > .6). BHAD activity was not related to any measured variable. These results confirm that an inverse relationship is present relating VO2max and running economy. Also, data herein indicate that maximal activities of key marker enzymes of the citric acid cycle and oxidative phosphorylation are likely a significant factor determining whole-body maximal oxygen consumption in endurance trained males and females.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-03282006-122132 |
| Date | 31 March 2006 |
| Creators | McMillan, Ryan Peyton |
| Contributors | Dennis Landin, Robert Wood, Arnold Nelson |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-03282006-122132/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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