Early onset of pulmonary gas exchange disturbance during progressive exercise in healthy active men.
J Appl Physiol (1985)
; 92(5): 1879-84, 2002 May.
Article
em En
| MEDLINE
| ID: mdl-11960937
ABSTRACT
Some recent studies of competitive athletes have shown exercise-induced hypoxemia to begin in submaximal exercise. We examined the role of ventilatory factors in the submaximal exercise gas exchange disturbance (GED) of healthy men involved in regular work-related exercise but not in competitive activities. From the 38 national mountain rescue workers evaluated (36 +/- 1 yr), 14 were classified as GED and were compared with 14 subjects matched for age, height, weight, and maximal oxygen uptake (VO2 max; 3.61 +/- 0.12 l/min) and showing a normal response (N). Mean arterial PO2 was already lower than N (P = 0.05) at 40% VO2 max and continued to fall until VO2 max (GED 80.2 +/- 1.6 vs. N 91.7 +/- 1.3 Torr). A parallel upward shift in the alveolar-arterial oxygen difference vs. %VO2 max relationship was observed in GED compared with N from the onset throughout the incremental protocol. At submaximal intensities, ideal alveolar PO2, tidal volume, respiratory frequency, and dead space-to-tidal volume ratio were identical between groups. As per the higher arterial PCO2 of GED at VO2 max, subjects with an exaggerated submaximal alveolar-arterial oxygen difference also showed a relative maximal hypoventilation. Results thus suggest the existence of a common denominator that contributes to the GED of submaximal exercise and affects the maximal ventilatory response.
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Base de dados:
MEDLINE
Assunto principal:
Transtornos Respiratórios
/
Testes de Função Respiratória
/
Exercício Físico
/
Esforço Físico
Tipo de estudo:
Diagnostic_studies
Limite:
Adult
/
Humans
/
Male
Idioma:
En
Ano de publicação:
2002
Tipo de documento:
Article