VO2 off transient kinetics in extreme intensity swimming

Ana Sousa, Pedro Figueiredo, Kari L. Keskinen, Ferran A. Rodríguez, Leandro Machado, João P. Vilas-Boas, Ricardo J. Fernandes

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)


Inconsistencies about dynamic asymmetry between the on- and off-transient responses in oxygen uptake are found in the literature. Therefore, the purpose of this study was to characterize the oxygen uptake off-transient kinetics during a maximal 200-m front crawl effort, as examining the degree to which the on/off regularity of the oxygen uptake kinetics response was preserved. Eight high level male swimmers performed a 200-m front crawl at maximal speed during which oxygen uptake was directly measured through breath-by-breath oxymetry (averaged every 5 s). This apparatus was connected to the swimmer by a low hy-drodynamic resistance respiratory snorkel and valve system. Results: The on- and off-transient phases were symmetrical in shape (mirror image) once they were adequately fitted by a single-exponential regression models, and no slow component for the oxygen uptake response was developed. Mean (± SD) peak oxygen uptake was 69.0 (± 6.3) mL·kg-1·min-1, significantly correlated with time constant of the off-transient period (r = 0.76, p < 0.05) but not with any of the other oxygen off-transient kinetic parameters studied. A direct relationship between time constant of the off-transient period and mean swimming speed of the 200-m (r = 0.77, p < 0.05), and with the amplitude of the fast component of the effort period (r = 0.72, p < 0.05) were observed. The mean amplitude and time constant of the off-transient period values were significantly greater than the respective on-transient. In conclusion, although an asymmetry between the on- and off kinetic parameters was verified, both the 200-m effort and the respectively recovery period were better characterized by a single exponential regression model.

Original languageEnglish
Pages (from-to)546-552
Number of pages7
JournalJournal of Sports Science and Medicine
Issue number3
Publication statusPublished - Sept 2011
Externally publishedYes


  • Front crawl
  • Oxygen uptake kinetics
  • Recovery
  • Swimming

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation


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