Cardiopulmonary response to exercise in COPD and overweight patients: relationship between unloaded cycling and maximal oxygen uptake profiles.

Biomed Res Int

Service des Explorations Fonctionnelles Respiratoires, Hopital Nord (Assistance Publique-Hôpitaux de Marseille) and UMR MD2, Faculté de Médecine Secteur Nord, Boulevard Pierre Dramard, 13916 Cedex 20 Marseille, France.

Published: December 2015

AI Article Synopsis

  • The study examined how cardiopulmonary responses to unloaded cycling differ among healthy individuals, COPD patients, and overweight individuals.
  • Significant increases in heart rate were found in COPD and hypoxemic overweight subjects after unloaded cycling, compared to normoxemic individuals and healthy controls.
  • The results suggest that measuring ventilation during unloaded cycling could help predict the exercise performance of COPD patients and overweight individuals during rehabilitation.

Article Abstract

Cardiopulmonary response to unloaded cycling may be related to higher workloads. This was assessed in male subjects: 18 healthy sedentary subjects (controls), 14 hypoxemic patients with chronic obstructive pulmonary disease (COPD), and 31 overweight individuals (twelve were hypoxemic). They underwent an incremental exercise up to the maximal oxygen uptake (VO2max), preceded by a 2 min unloaded cycling period. Oxygen uptake (VO2), heart rate (HR), minute ventilation (VE), and respiratory frequency (fR) were averaged every 10 s. At the end of unloaded cycling period, HR increase was significantly accentuated in COPD and hypoxemic overweight subjects (resp., +14 ± 2 and +13 ± 1.5 min(-1), compared to +7.5 ± 1.5 min(-1) in normoxemic overweight subjects and +8 ± 1.8 min(-1) in controls). The fR increase was accentuated in all overweight subjects (hypoxemic: +4.5 ± 0.8; normoxemic: +3.9 ± 0.7 min(-1)) compared to controls (+2.5 ± 0.8 min(-1)) and COPDs (+2.0 ± 0.7 min(-1)). The plateau VE increase during unloaded cycling was positively correlated with VE values measured at the ventilatory threshold and VO2max. Measurement of ventilation during unloaded cycling may serve to predict the ventilatory performance of COPD patients and overweight subjects during an exercise rehabilitation program.

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Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4383510PMC
http://dx.doi.org/10.1155/2015/378469DOI Listing

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