Descriptive statistics were used to describe the characteristics of the subjects.
Data are presented as mean ± standard deviation. The Shapiro–Wilk test was applied
to ensure a Gaussian distribution of the data. Unpaired t test was used to compare the
baseline characteristics between training and control groups. Repeated measures
analysis of variance (ANOVA) was performed with time (pre and post) and intervention
(HEx and control) as repeated factors. Comparison between baseline and subsequent
time points (within-group differences), as well as between intervention
groups at each time point (between-group differences), were done in both 24-hour,
awake and sleep averages, as well as hourly averages. Bonferroni post-hoc analysis
was performed to identify significant differences that were indicated. The Mann–Whitney
U test was also used for non-parametric analysis. The level of significance was set at p
b 0.05. The statistical program SPSS 20.0 for Mac (SPSS Inc., Chicago IL, USA) was used
to perform the statistical analyses.