Validation of an equation for estimating maximal oxygen consumption of nonexpert adult swimmers

Abstract

ObjectiveTo validate an equation to estimate the maximal oxygen consumption (VO2max) of nonexpert adult swimmers.MethodsParticipants were 22 nonexpert swimmers, male, aged between 18 and 30 years (age: 23.1 ± 3:59 years; body mass: 73.6 ± 7:39 kg; height 176.6 ± 5.53 cm; and body fat percentage: 15.9% ± 4.39%), divided into two subgroups: G1 – eleven swimmers for the VO2max oximetry and modeling of the equation; and G2 – eleven swimmers for application of the equation modeled on G1 and verification of their validation. The test used was the adapted Progressive Swim Test, in which there occurs an increase in the intensity of the swim every two laps. For normality and homogeneity of data, Shapiro-Wilk and Levene tests were used, the descriptive values of the average and standard deviation. The statistical steps were: (1) reliability of the Progressive Swim Test – through the paired t-test, intraclass correlation coefficient (ICC), and the Pearson linear correlation (R) relative to the reproducibility, the coefficient of variation (CV), and standard error measurement (SEM) for the absolute reproducibility; (2) in the model equation to estimate VO2max, a relative VO2 was established, and a stepwise multiple regression model was performed with G1 – so the variables used were analysis of variance regression (AR), coefficient of determination (R2), adjusted coefficient of determination (R2a), standard error of estimate (SEE), and Durbin–Watson (DW); (3) validation of the equation – the results were presented in graphs, where direct (G1) and estimated (G2) VO2max were compared using independent t-test, linear regression (stressing the correlation between groups), and Bland–Altman (the bias agreement of the results). All considered a statistical significance level of P < 0.05.ResultsOn the trustworthiness of the Progressive Swim Test adapted presented as high as observed (R and ICC > 0.80, CV < 10%, and SEM < 2%). In the equation model, VO2max has been considered the third model as recommended due to the values found (AR < 0.01, R = 0795, R2 = 0633; R2a = 0.624, SEE = 7.21, DW = 2.06). Upon validation of the equation, no significant differences occurred between G1 and G2 (P > 0.01), linear regression stressed a correlation between the groups (R > 0.80, P < 0.01), and Bland–Altman plotting of the results was within the correlation limits of 1.96 (95% confidence interval).ConclusionThe estimating equation for VO2max for nonexpert swimmers is valid for its application through the Progressive Swim Test, providing to contribute in prescribing the swimming lessons as a method of evaluating the physical condition of its practitioners.

Applicability of an Indirect VO2max Test: Its Association with the 400 Meters Freestyle Performance

“…The BHR, AHR, RPE, and NLP variables (adding the time for conducting the tests) were necessary to the standardization with previous studies regarding the PSwT, since these presented security and consistency in the reproducibility and validity verification 11,12 . These variables were essential to determine the physical condition of these swimmers, and especially HR and RPE, were important in the verification of the state of the swimmers immediately before and after the tests 5,19 , in the verification of the longest distance incrementally swum by the swimmer in the PSwT 11 , and in the least amount of time in the simulated 400 MF test 1,23 .…”

“…While verifying the reproducibility of the PSwT, Veronese da Costa, Costa, Carlos, Guerra, Silva, Barbosa 11 regarded the NLP as a predictor of the physical conditioning of the non-expert swimmers due to the fact the distance over a predetermined time was used as a criterion for exercise intensity in swimming 11 . By validating the equation which estimates the VO2max using the results obtained in the PSwT (i.e., through NLP, BM in kg and AHR), the test was found to be appropriate for non-expert adult swimmers as a way of assessing physical conditioning 12 . In the simulated 400 MF, it was observed that, even demanding the maximum performance possible, there were alterations in swimming intensity over the course of the test.…”

“…The PSwT was applied according to the protocol of Veronese da Costa 12 , which corresponds to an increase of swimming intensity of one second for every two laps (meaning every 50 meters). The test ends when the swimmer cannot arrive at the distance which marks the first or last five meters of the swimming pool twice in a row.…”

“…The test ends when the swimmer cannot arrive at the distance which marks the first or last five meters of the swimming pool twice in a row. From the application of the PSwT 12 , it was possible to estimate the VO2max of non-expert adult swimmers through the following equation: VO2max (ml.kg …”

“…These results are in accordance with other studies that evaluated the VO2max at the end of the 400 meters freestyle in maximum speed by elite swimmers, which showed results between 45 and 62 ml.kg−1min −1 12 . Following the adaptation, design reproducibility, and validity stages of PSwT 11,12 , the next step should be its application in order to verify its sensibility and its use as a source of information regarding the cardiorespiratory aptitude of swimmers.…”