Time Limit and V·O₂Slow Component at Intensities Corresponding to V·O₂max in Swimmers

Abstract

The purpose of this study was to measure, in swimming pool conditions and with high level swimmers, the time to exhaustion at the minimum velocity that elicits maximal oxygen consumption (TLim at vVO(2)max), and the corresponding VO(2) slow component (O(2)SC). The vVO(2)max was determined through an intermittent incremental test (n = 15). Forty-eight hours later, TLim was assessed using an all-out swim at vVO(2)max until exhaustion. VO(2) was measured through direct oximetry and the swimming velocity was controlled using a visual light-pacer. Blood lactate concentrations and heart rate values were also measured. Mean VO(2)max for the incremental test was 5.09 +/- 0.53 l/min and the corresponding vVO(2)max was 1.46 +/- 0.06 m/s. Mean TLim value was 260.20 +/- 60.73 s and it was inversely correlated with the velocity of anaerobic threshold (r = -0.54, p < 0.05). This fact, associated with the inverse relationship between TLim and vVO(2)max (r = -0.47, but only for p < 0.10), suggested that swimmers' lower level aerobic metabolic rate might be associated with a larger capacity to sustain that exercise intensity. O(2)SC reached 274.11 +/- 152.83 l/min and was correlated with TLim (r = 0.54), increased ventilation in TLim test (r = 0.52) and energy cost of the respiratory muscles (r = 0.51), for p < 0.05. These data suggest that O(2)SC was also observed in the swimming pool, in high level swimmers performing at vVO(2)max, and that higher TLim seems to correspond to higher expected O(2)SC amplitude. These findings seem to bring new data with application in middle distance swimming.

VO2Kinetics and Metabolic Contributions Whilst Swimming at 95, 100, and 105% of the Velocity atVO2 maxSousa1, Vilas-Boas2, Fernandes3 2014BioMed Research International374530View full textAdd to dashboardCite

“…The mean values obtained at the end of the incremental protocol are in accordance with those presented for middle distance swimmers [5, 6], but lower than those described for elite swimmers [8–11], runners [32, 33], cyclists [34, 35], and rowers [36, 37], probably explained by the use of a larger muscle mass in these sports. Also, the observed [La − ] max⁡ mean values are lower compared to other exercise modes, which can explain the lower R mean values found.…”

“…Collectively, these studies seem to evidence that time sustained at intensities around vVO 2max⁡ depends also on the conditions in which they occurred. In fact, it has been reported that swimming flume might influence the VO 2max⁡ , vVO 2max⁡ , and the Tlim-vVO 2max⁡ assessment, as well as the swimming technique, and, therefore, could explain the differences found [8]. …”

“…Each square wave exercise consisted of three distinct phases: 10 min warm-up at 50% of the VO 2max⁡ , a short rest period (300 s), and the maintenance of the specific swimming intensity until exhaustion [8, 11]. The square wave exercises ended when the swimmers could no longer maintain the required velocity dictated by the visual feedback.…”

“…Though being conducted in nonspecific swimming pool conditions (swimming flume), these studies evidenced that Tlim-vVO 2max⁡ depended inversely on the vVO 2max⁡ but was not related with VO 2max⁡ . To date, few studies have been conducted in conventional competition conditions [1, 8–13], and none has proposed how VO 2 kinetics might impact concerning distinct vVO 2max⁡ swimming intensities.…”

“…More recently, the extreme exercise domain has been proposed for power outputs that lead to exhaustion before VO 2max⁡ is attained [19], with the kinetics of VO 2 characterized by the development of an evident fast component with insufficient time for the appearance of a discernible VO 2 slow component [20]. Although the characteristics of the VO 2 kinetics in the moderate and heavy intensity domains are well described (particularly in cycle and running ergometer exercise), few studies have investigated it during swimming around the VO 2max⁡ intensity [7, 8, 11]. Moreover, these studies have only conducted a simplistic VO 2 kinetics characterization by presenting the VO 2 slow component as the unique kinetics parameter.…”