JOURNAL OF SPORTS SCIENCE & MEDICINE

Research article

VO2 OFF TRANSIENT KINETICS IN EXTREME INTENSITY SWIMMING

Ana Sousa1, Pedro Figueiredo1, Kari L. Keskinen2, Ferran A. Rodríguez3, Leandro Machado1, João P. Vilas-Boas1, Ricardo J. Fernandes1

1Centre of Research, Education, Innovation and Intervention in Sport, Faculty of Sport, University of Porto, Portugal, 2Finnish Society of Sport Sciences, Finland, 3National Institute of Physical Education of Catalonia (INEFC), University of Barcelona, Barcelona, Spain

Received   18 April 2011 Accepted   20 July 2011 Published   01 September 2011

© Journal of Sports Science and Medicine (2011) 10, 546 - 552

ABSTRACT

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 hydrodynamic 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. Key words: Swimming, oxygen uptake kinetics, recovery, front crawl.

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