Validade do teste de 30 minutos (T-30) na determinação da capacidade aeróbia, parâmetros de braçada e performance aeróbia de nadadores treinados

Abstract

tion of the aerobic training intensity (5)(6) and performance prediction of long distance events (2) . However, the determination of the anaerobic threshold using the blood lactate concentration needs specific equipment and has a financial acquisition and operational cost, which is not possible for most swimming teams in Brazil. Moreover, it consists of an invasive test which requires care with hygiene and safety (2) , limiting thus, its use in most clubs and fitness centers. Therefore, many researchers try to make less costly and of easy application assessment protocols available, which also precisely and reliably evaluate and monitor training (1)(2)(6)(7) .Olbrecht et al. (6) have developed the T-30 test, which consists in moving the longest distance in 30 minutes at regular rhythm from beginning to end of the test. The mean velocity of the T-30 test (VT-30) has been highly correlated with the anaerobic velocity threshold (6,(8)(9)(10)(11) and with swimming performance (12) , which is non-invasive and of easy application.Nevertheless, the swimming mechanics also plays a crucial role in the myriad of determinant factors of swimming performance and should be considered in the assessments. It has been demonstrated that the dislocation velocity in swimming is the product of the stroke rate (SR) by the stroke length (SL) and variations in the swimming velocity by training and lack of training mainly occur by modifications in SR and SL (13)(14) . For this reason, these variables have been the aim of studies on elite swimming (13,15) , educational status (16) , disabled subjects (17) and for technical analysis between swimmers and triathletes (18) .Costill et al. (7) presented the stroke index (SI) as the product of the swimming velocity by the distance completed per stroke cycle, and found significant correlations among oxygen uptake (VO 2 ), swimming velocity and this variable. These authors demonstrate that the swimmer's energy cost in crawl depends on the technique of his/her stroke. Keskinen and Komi (19) demonstrated that the relationship between SR and SL is influenced by the increase of the effort intensity. When the swimming velocity is lower than the anaerobic threshold intensity, the swimmers are able to control the velocity and simultaneously keep the stroke length steady. However, when the effort is performed at intensities above the anaerobic threshold, a progressive reduction in SL is observed, this fact being relied on the development of local muscle fatigue. Dekerle et al. (8) highlighted that the swimmer should be able to choose the SR corresponding to the lowest energy cost during his event, suggesting hence a relationship between physiological and technical parameters in swimming. Langeani et al. (20) demonstrated the occurrence of increase and sudden decrease of SR and SL, respectively, following the lactacidemia behavior in progressive exercise.Thus, it was shown that dynamic lactate balance may be observed during extensive exercise at intensities corresponding to the Lan (6,21) ; hence, this ...

Anaerobic Threshold in Stand-up Paddle: Comparison Between Direct and Alternative Methods

“…According to our results, V30min may be used as an alternative method to assess aerobic capacity, in which it is supported by previous observations in swimming (5,14,15). However, although this method is noninvasive and of low cost, in swimming, from a psychological standpoint, the use of a 30-minute continuous effort has been related to high levels of demotivation, hence, influencing the results (13).…”

Série de treinamento intervalado de alta intensidade como índice de determinação da tolerância à acidose na predição da performance anaeróbia de natação

“…Partly confirming the validity of the technical indices for performance prediction, high correlations among the SL, SI and P100 were verified in this study (table 1). The significant correlations among SL, SI and AT demonstrate the importance of the swimmer's technical skill and confirm the relationship between physiological and technical parameters in swimming (16)(17)(18)20,24) . These correlations may be explained by the swimmers' difference of skill in performing a higher number of strokes with a better strength application, which is important in the minimization of drag and fatigue decrease, being able to develop strength for a longer time even in high intensity exercises where the accumulation of lactic acid may cause great discomfort and swimmer's efficiency and coordination loss (20) .…”

What pacing strategy 800m and 1500m swimmers use?

“…The parabolic PS is characterized by a faster start, followed by a reduction in speed in the middle of the race and then an increase in the last 50m, called sprint. This decrease in speed in the middle of the race, besides interfering with the number and length of strokes, is intended to provide the athlete with energy savings until the end of the race, which in turn becomes decisive in long races [15][16][17][18] .…”