Functional exercise capacity evaluation in an aquatic environment

ABSTRACT The aim of this study was to investigate the correlation between distance achieved and compare the average speed while walking in the six-minute walk test (6MWT) performed on solid ground and in the three-minute walk test in water (3MWT-W) with healthy young individuals, as well as compare physiological (heart rate, oxygen saturation and blood pressure) and symptomatic variables between tests. It is a cross-sectional study, with a sample of 20 healthy young subjects. All patients underwent spirometry, answered a questionnaire on health and physical activity, in addition to performing the 6MWT and 3MWT-W. Statistical analysis used the Shapiro-Wilk test to evaluate normality of the data, the paired Student's t-test and Wilcoxon in the comparisons between the variables and the Pearson correlation coefficient to verify associations. Statistical significance of p < 0.05 was adopted. The mean age was 22 (±2) years, the mean BMI was 23 (±3) kg/m2 and all subjects had normal pulmonary function. The average distance achieved in the 6MWT was of 657 (±43) meters and in the 3MWT-W of 135 (±13) meters. A weak correlation between the 3MWT-W and 6MWT (r=0.35) was found. The speed during the tests showed a statistically significant difference (3MWT-W 0.75±0.07 versus 6MWT 1.85±9.1, p<0.0001). There was no difference in the initial and the final physiological variables between 3MWT-W and 6MWT. The 3MWT-W may be a good tool for evaluation and exercise prescription in the aquatic environment, but showed a weak correlation with the 6MWT and similar physiological strain, though further studies are suggested to confirm this finding.