The sample size was calculated taking in consideration the minimum clinically significant differences in peak VO2 during ISWT. In a previous study with healthy sub- jects, peak VO2 during ISWT presented a standard devia- tion of 609 mL/min, with a reduction of 605 mL/min representing the lower limit of normal [12]. We therefore considered the reduction of more than 605 mL/min as clin- ically significant for peak VO2 related to ISWT. With the standardized effect size around 1 as well as probability al- pha error at 0.05 and beta of 0.20, we obtained the number of at least 16 participants in each research group.
Data were analyzed descriptively and are presented as mean and standard deviation when normally distributed and as median (interquartile range) when presented non- normal distribution. The normality of variables was inves- tigated by Kolmogorov-Smirnov test. To compare the means or medians of variables between patients and healthy subjects, we used the unpaired t test or Mann-Whitney U test, respectively. The correlations were assessed by Pear- son or Spearman coefficients according to the distribution of the studied variables. The probability of alpha error was set at 5% for all analyses.