| Effect of hyperoxia on aerobic and anaerobic performances and muscle metabolism during maximal cycling exercise. | |
| | |
MedLine Citation:
|
PMID: 10712578 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
The hyperoxia-improved tolerance to maximal aerobic performance was studied in relation to exercising muscle metabolic state. Five students were submitted to four different tests on a cycle ergometer, each being conducted under normoxia and hyperoxia (60% FiO2) on separate days: Test 1, a progressive exercise until exhaustion to determine the maximal work load (Wmax) which was unchanged by hyperoxia; Test 2, an exercise at Wmax (287 +/- 12 W) until exhaustion to determine the performance time (texh) which was elevated by 38% under hyperoxia but exhaustion occurred at the same arterial proton and lactate concentrations; Test 3 (S-Exercise test) consisted of cycling at Wmax for 90% normoxic-texh (4.8 +/- 0.5 min under both O2 conditions) then followed by a 10-s sprint bout during which the total work output (Wtot) was determined; Wtot was elevated by 15% when exercising under hyperoxia; Test 4 (M-Exercise test) consisted also of cycling at Wmax for 4.8 +/- 0.5 min with blood and muscle samples taken at rest and at the end of the exercise to compare the level of different metabolites. During hyperoxic M-Exercise test, glycogen was twice more depleted whereas glucose-6-phosphate and lactate were less accumulated when compared with normoxia. No significant differences were observed for pyruvate, phosphocreatine and muscle/blood lactate ratio between the two conditions. Conversely to normoxia, levels of ATP, ADP and total NADH were maintained at their resting level under 60% FiO2. These data lead us to suppose a higher oxidation rate for pyruvate and NADH in mitochondria, thereby lowering the metabolic acidosis and allowing a better functioning of the glycolytic and contractile processes to delay the time to exhaustion. |
| | |
Authors:
|
M T Linossier; D Dormois; L Arsac; C Denis; J P Gay; A Geyssant; J R Lacour |
Related Documents
:
|
14631128 - Modified exercise test in screening for mitochondrial myopathies--adjustment of workloa... 22443448 - Dental erosive wear and salivary flow rate in physically active young adults. 15070938 - Dichloroacetate therapy attenuates the blood lactate response to submaximal exercise in... 18308878 - Heart rate-based protocols for exercise challenge testing do not ensure sufficient exer... 19554028 - Effects of aerobic training intensity on resting, exercise and post-exercise blood pres... 18647728 - Whole-body intensive rehabilitation is feasible and effective in chronic stroke survivo... |
Publication Detail:
|
Type: Journal Article |
Journal Detail:
|
Title: Acta physiologica Scandinavica Volume: 168 ISSN: 0001-6772 ISO Abbreviation: Acta Physiol. Scand. Publication Date: 2000 Mar |
Date Detail:
|
Created Date: 2000-04-21 Completed Date: 2000-04-21 Revised Date: 2004-11-17 |
Medline Journal Info:
|
Nlm Unique ID: 0370362 Medline TA: Acta Physiol Scand Country: ENGLAND |
Other Details:
|
Languages: eng Pagination: 403-11 Citation Subset: IM; S |
Affiliation:
|
Laboratoire de Physiologie - GIP Exercice, Faculté de Médecine Saint-Etienne, 15 rue Ambroise Paré, Saint-Etienne Cedex 2, France. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adult Aerobiosis Anaerobiosis Blood / metabolism Exercise / physiology* Exercise Test Glycolysis Humans Hydrogen-Ion Concentration Hyperoxia / blood, metabolism*, physiopathology Lactic Acid / blood Male Muscle Contraction / physiology Muscle, Skeletal / metabolism*, physiopathology |
| Chemical | |
Reg. No./Substance:
|
50-21-5/Lactic Acid |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Na+-Ca2+ exchange current from rabbit isolated atrioventricular nodal and ventricular myocytes compa...
Next Document: Immunomodulation by 8-week voluntary exercise in mice.