Impact of supine versus upright exercise on muscle deoxygenation heterogeneity during ramp incremental cycling is site specific.
Eur J Appl Physiol
; 121(5): 1283-1296, 2021 May.
Article
em En
| MEDLINE
| ID: mdl-33575912
ABSTRACT
PURPOSE:
We tested the hypothesis that incremental ramp cycling exercise performed in the supine position (S) would be associated with an increased reliance on muscle deoxygenation (deoxy[heme]) in the deep and superficial vastus lateralis (VLd and VLs, respectively) and the superficial rectus femoris (RFs) when compared to the upright position (U).METHODS:
11 healthy men completed ramp incremental exercise tests in S and U. Pulmonary [Formula see text]O2 was measured breath-by-breath; deoxy[heme] was determined via time-resolved near-infrared spectroscopy in the VLd, VLs and RFs.RESULTS:
Supine exercise increased the overall change in deoxy[heme] from baseline to maximal exercise in the VLs (S 38 ± 23 vs. U 26 ± 15 µM, P < 0.001) and RFs (S 36 ± 21 vs. U 25 ± 15 µM, P < 0.001), but not in the VLd (S 32 ± 23 vs. U 29 ± 26 µM, P > 0.05).CONCLUSIONS:
The present study supports that the impaired balance between O2 delivery and O2 utilization observed during supine exercise is a regional phenomenon within superficial muscles. Thus, deep muscle defended its O2 delivery/utilization balance against the supine-induced reductions in perfusion pressure. The differential responses of these muscle regions may be explained by a regional heterogeneity of vascular and metabolic control properties, perhaps related to fiber type composition.Palavras-chave
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oxigênio
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Exercício Físico
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Decúbito Dorsal
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Músculo Quadríceps
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Posição Ortostática
Limite:
Adult
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Humans
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Male
Idioma:
En
Revista:
Eur J Appl Physiol
Ano de publicação:
2021
Tipo de documento:
Article