Please use this identifier to cite or link to this item:
http://hdl.handle.net/11375/23247
Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | Tarnopolsky, Mark | - |
dc.contributor.author | McKenzie, Scott | - |
dc.date.accessioned | 2018-07-30T19:39:40Z | - |
dc.date.available | 2018-07-30T19:39:40Z | - |
dc.date.issued | 1999-04-14 | - |
dc.identifier.uri | http://hdl.handle.net/11375/23247 | - |
dc.description.abstract | Endurance exercise has been shown to both raise and lower leucine oxidation in studies in rodents. We studied the effects of a 38 d endurance exercise training program upon leucine turnover during a 90 min exercise bout at 60 % VO_2peak in 6 males and 6 females. Subjects were studied at both the same absolute (ABS) and relative (REL) exercise intensities post-training. Pre (PRE)- and post-training measurements were taken for analysis of: L-[1-^13C]leucine turnover, muscle branched-chain oxoacid dehydrogenase activity (BCOAD), muscle glycogen, phosphocreatine and ATP utilization, and resting enzyme activity of citrate synthase (CS) and NADH-cytochrome c-oxidoreductase (complex I-III). We also determined total substrate oxidation by indirect calorimetry, and plasma lactate, glucose, and insulin concentrations. The exercise training resulted in a significant increase in both CS (P < 0.001) and complex I- III (P < 0.05) activities. Leucine oxidation increased during exercise for the pre-training trial (P < 0.001), however, there was no increase for either the post-training ABS or REL trial. Leucine oxidation was significantly lower for females at all time points (P < 0.01). Total BCOAD activity was also significantly increased when comparing the PRE to both ABS and REL trials (P < 0.001). The % activation of BCOAD was significantly increased from t=0 to t=90 in both the PRE and REL exercise trials with the increase in PRE being greater (P < 0.001 (PRE), and P < 0.05 (REL)). Exercise RER was lower for females vs. males (P< 0.05). In addition, the ABS trial was significantly lower than PRE and REL (P < 0.01). Plasma lactate was significantly lower at all time points for ABS vs. PRE (P < 0.001) and REL vs. PRE at t=30 min of exercise (P < 0.001). Resting muscle glycogen was higher for both ABS and REL vs. PRE (P < 0.001). In conclusion, we found that 38 d of endurance exercise training significantly attenuated both leucine oxidation and BCOAD activation during 90 min of endurance exercise at 60 % VO_2peak for both absolute and relative exercise intensities. In addition, females were also shown to oxidize a greater proportion of energy from lipid and a lesser amount from carbohydrates and proteins during exercise. | en_US |
dc.language.iso | en | en_US |
dc.subject | endurance | en_US |
dc.subject | exercise | en_US |
dc.subject | leucine | en_US |
dc.subject | oxidation | en_US |
dc.subject | 2-oxo acid | en_US |
dc.subject | dehydrogenase | en_US |
dc.subject | humans | en_US |
dc.title | Endurance Exercise Training Attenuates Leucine Oxidation and Branched-Chain 2-Oxo Acid Dehydrogenase Activation During Exercise in Humans | en_US |
dc.type | Thesis | en_US |
dc.contributor.department | Human Biodynamics | en_US |
dc.description.degreetype | Thesis | en_US |
dc.description.degree | Master of Science (MS) | en_US |
Appears in Collections: | Digitized Open Access Dissertations and Theses |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
mckenzie_scott_1999Apr_masters.pdf | 10.63 MB | Adobe PDF | View/Open |
Items in MacSphere are protected by copyright, with all rights reserved, unless otherwise indicated.