*3.1.5. Statistical analysis*

The normality of the ANS activity data was not confirmed by using the Kolmogorov-Smirnov and Shapiro-Wilk tests. We used a nonparametric method in this research. The LF/HF ratio among three trials (rest, MI, post) under two MI conditions (10% MI and 50% MI conditions) were compared using the Friedman test and Scheffe's post hoc test.

We also calculated the relative value obtained by dividing the LF/HF ratio during MI under four MI conditions by that at rest. The relative values among two MI conditions were compared using the Wilcoxon signed rank test. We used SPSS statistics ver. 19 (IBM Corp., USA) for statistical analysis. The threshold for statistical significance was set to p = 0.05.
