Note: Boot SE, Boot ULCI and Boot LLCI refer to the standard error,
upper limit and lower limit, respectively, of the 95% confidence
interval of the indirect effect estimated by the percentile bootstrap
method with deviation correction, the same below.
Second, the mediating effect of boredom between physical activity and
negative mood was tested using Model 4 in PROCESS 3.3 (Model 4 is a
simple mediating model). As shown in table 7, physical activity had a
significant negative predictive effect on negative mood (β =-0.12,t =-2.70, p <0.01), and after the mediating
variable was added, the negative effect was no longer significant
(β =-0.05, t =-1.42, p >0.05). Physical
activity had a significant negative predictive effect on boredom
(β =-0.11, t =-2.55, p <0.05), and boredom
had a significant positive predictive effect on negative mood
(β =0.61, t =17.39, p <0.01). In addition,
the 95% confidence interval for the direct effect of physical activity
on negative mood contained 0, but that for the mediating effect of
boredom did not. As shown in table 8, physical activity predicts
negative mood through the mediating effect of boredom (-0.07),
accounting for 58.12% of the total effect (-0.12).