Excess VO2 during ramp exercise is positively correlated to intercostal muscles deoxyhemoglobin levels above the gas exchange threshold in young trained cyclists.

Détails

ID Serval
serval:BIB_D7A88A7EFDA1
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Excess VO2 during ramp exercise is positively correlated to intercostal muscles deoxyhemoglobin levels above the gas exchange threshold in young trained cyclists.
Périodique
Respiratory physiology & neurobiology
Auteur⸱e⸱s
Oueslati F., Girard O., Tabka Z., Ahmaidi S.
ISSN
1878-1519 (Electronic)
ISSN-L
1569-9048
Statut éditorial
Publié
Date de publication
07/2016
Peer-reviewed
Oui
Volume
228
Pages
83-90
Langue
anglais
Notes
Publication types: Journal Article
Publication Status: ppublish
Résumé
We assessed respiratory muscles oxygenation responses during a ramp exercise to exhaustion and further explored their relationship with the non-linear increase of VO2 (VO2 excess) observed above the gas-exchange threshold. Ten male cyclists completed a ramp exercise to exhaustion on an electromagnetically braked cycle-ergometer with a rate of increment of 30Wmin(-1) with continuous monitoring of expired gases (breath-by-breath) and oxygenation status of intercostal muscles. Maximal inspiratory and expiratory pressure measurements were taken at rest and at exhaustion. The VO2 excess represents the difference between VO2max observed and VO2max expected using linear equation between the VO2 and the intensity before gas-exchange threshold. The deoxyhemoglobin remained unchanged until 60% of maximal aerobic power (MAP) and thereafter increased significantly by 37±18% and 40±22% at 80% and 100% of MAP, respectively. Additionally, the amplitude of deoxyhemoglobin increase between 60 and 100% of MAP positively correlated with the VO2 excess (r=0.69, p<0.05). Compared to exercise start, the oxygen tissue saturation index decreased from 80% of MAP (-4.8±3.2%, p<0.05) onwards. At exhaustion, maximal inspiratory and expiratory pressures declined by 7.8±16% and 12.6±10% (both p<0.05), respectively. In summary, our results suggest a significant contribution of respiratory muscles to the VO2 excess phenomenon.

Mots-clé
Adolescent, Bicycling/physiology, Breath Tests, Exercise/physiology, Exercise Test, Hemoglobins/metabolism, Humans, Intercostal Muscles/metabolism, Male, Muscle Strength/physiology, Oxygen/metabolism, Oxygen Consumption/physiology, Pressure, Pulmonary Gas Exchange/physiology, Respiration, Spectroscopy, Near-Infrared, Excess VO2, NIRS, Respiratory muscles oxygenation, Respiratory muscles strength
Pubmed
Web of science
Création de la notice
16/02/2016 17:51
Dernière modification de la notice
20/08/2019 15:57
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