Revista Brasileira de Medicina do Esporte
Print version ISSN 1517-8692
SILVA, Paulo Roberto Santos et al. Effect of time intervals of ventilatory sampling in the variability of maximum oxygen uptake in professional soccer players. Rev Bras Med Esporte [online]. 1999, vol.5, n.2, pp.43-46. ISSN 1517-8692. http://dx.doi.org/10.1590/S1517-86921999000200002.
The purpose of this investigation was to verify the impact of seven ventilatory time intervals on the maximum oxygen uptake (VO2 max) in professional soccer players. Eighteen male soccer players aged 24.4 ± 4 (18-31), weight 72.5 ± 5.9 kg (62-83) and height 176.5 ± 7 cm (164-188) were submitted to a maximum exercise test on treadmill, using the continuous protocol. The heart rate response was recorded by means of computerized ECG with 12 leads, simultaneously. The respiratory exchange ratio, carbon dioxide production, oxygen uptake and pulmonary ventilation were calculated by means of the spirometric computerized system. The results of this study demonstrated that there was significant variability (p < 0.05) in VO2 max only when it was compared instantaneously and by breath-by-breath response, in relation to other intervals analyzed (10, 20, 30, 40, 50 and 60 seconds, respectively). In conclusion, the authors observed that VO2 max increases were proportional to those found in the ventilatory sample intervals during the progressive intensity exercise. However, the higher time interval underestimated its increase. Thus, the authors suggest that the investigator should utilize mean intervals in a range between 10 and 60 seconds, since no significant statistic difference was verified among these intervals.
Keywords : Maximum oxygen uptake; Spiroergometry; Time interval; Professional soccer players; Sports medicine.