Statistical analysis
Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS Inc., Chicago, IL, USA) version 20.0 J for Windows®. The Steel-Dwass method was used for statistical evaluations. The baseline values of the intervention and the non-intervention groups were compared using Welch’s t-test. A paired t-test was performed before and after the training intervention. The effect size (d) was calculated from the baseline and the values after 4 weeks in the intervention and non-intervention groups. The probability level accepted as the criterion for statistical significance was set at 5%.