Cinética do consumo de oxigênio a intensidades de nado moderada e extrema

Abstract

Introduction: Traditionally, studies regarding oxygen consumption kinetics are conducted at lower intensities, very different from those in which the sports performance occurs. Objective: Knowing that the magnitude of this physiological parameter depends on the intensity in which the effort occurs, it was intended with this study to compare the oxygen consumption kinetics in the 200 m front crawl at two different intensities: moderate and extreme. Methods: Ten male swimmers of international level performed two tests separated by 24h: (i) progressive and intermittent protocol of 7 x 200 m, with 30 seconds intervals and with increments of 0.05m.s -1 , to determine the anaerobic threshold correspondent step; and, (ii) 200 m at maximal velocity, in both expiratory gases were continuously collected breath-by-breath. Results: Significant differences were obtained between amplitude and time constant determined in the 200 m at extreme and moderate intensities, respectively (38.53 ± 5.30 ml. kg -1 .min -1 versus 26.32 ± 9.73 ml. kg -1 .min -1 and 13.21 ± 5.86 s versus 18.89 ± 6.53 s (p ≤ 0.05). No differences were found in time delay (9.47 ± 6.42 s versus 12.36 ± 6.62 s, at extreme and moderate intensity, respectively (p ≤ 0.05). A negative correlation between time delay and time constant at the moderate intensity was reported (r = -0.74, p ≤ 0.05). Conclusions: Both intensities were well described by double-exponential fittings and there were significant differences between them in terms of amplitude and time constant.

Time limit and V̇O2 kinetics at maximal aerobic velocity: Continuous vs. intermittent swimming trials

“…V _ O 2 K parameters [time delay (TD), time constant (τ), and amplitude (A)] of the time-limit tests were determined by using: 1) bi-exponential modelling for the CT, since after a primary rise of the V _ O 2 values, a secondary rise (slow component) was observed (except for two swimmers); or 2) by monoexponential modelling for the IT 100 , since due to the short duration of the sets we did not observe the secondary rise of the V _ O 2 values, in accordance with previous studies (Rodríguez et al, 2003;Sousa et al, 2013;Almeida et al, 2020Almeida et al, , 2021. To remove the influence of the cardiodynamic phase on the subsequent V _ O 2 response, we chose to remove the first 20 s of data from the analysis (Pessôa Filho et al, 2012; Frontiers in Physiology frontiersin.org Reis et al, 2012;Espada et al, 2015;Almeida et al, 2020Almeida et al, , 2021.…”

Oxygen uptake kinetics and ventilatory and metabolic parameters do not differ between moderate‐intensity front crawl and breaststroke swimming

“…The FC VO 2max of our swimmers (54 ml −1 kg −1 min −1 ) was similar (50-61 ml −1 kg −1 min −1 ) to that reported by others, but the VO 2 kinetic response during FC was slower in our swimmers (Pelarigo et al, 2017;Reis et al, 2012aReis et al, , 2012bReis et al, , 2017Sousa et al, 2014). For example, our swimmers had a longer τ p , TD p , and MRT during FC, and a smaller A p compared to those undertaking moderate intensity 200, 600 m, and 30 min of FC swimming (Pelarigo et al, 2017;Reis et al, 2017;Sousa et al, 2013). More specifically, when compared to the findings of Reis et al (2017), who also utilized a swimming velocity equivalent to 80% of VT, the τ p of our swimmers was 9-10 s slower.…”

“…Further work is therefore required to confirm whether differences in kinetic parameters exist between strokes at faster velocities. Past studies utilizing the FC stroke have observed a slow component during high-intensity swimming (Pelarigo et al, 2017;Reis et al, 2012a;Sousa et al, 2013Sousa et al, , 2014. Given the slow component is indicative of muscle inefficiency, which will reduce exercise tolerance (Grassi et al, 2015), any stroke differences will have implications for swimming performance.…”

“…Since these developments, studies have compared the impact of exercise intensity (Pelarigo et al, 2017; Sousa et al, 2013, 2014), sex (Reis et al, 2017), fitness level (Reis et al, 2012a), and time‐trial performance (Reis et al, 2012b) on kinetics during front crawl (FC) swimming. These studies have greatly elucidated the pulmonary kinetic responses to FC in trained swimmers.…”

Physiological Responses During High-Intensity Interval Training in Young Swimmers

“…where ⩒O 2(t) represents the relative ⩒O 2 at a given time; ⩒O 2 base represents the ⩒O 2 at rest, which was calculated as the average of the first 30-s of the last minute before the start of the exercise (after 10-min of passive rest); TD, τ, and A represent the time delay, time constant, and amplitude of the primary phase of the ⩒O 2 response, respectively (Rodríguez et al, 2003;Sousa et al, 2013;Almeida et al, 2020). The oxygen deficit (O 2Def ) at the onset of the first 100 and 200-m of each IT protocol was measured as the product between mean response time (MRT) and A, where the MRT is TD × τ (Whipp et al, 2005).…”