Table 5.

HLM estimates of the effect of physical activity time on adolescent mental health.

Variable type	Variable name	Model 1	Model 2
Independent variable	Physical exercise time	0.105	0.006
	Mental health level	0.001	0.001
	Gender	1.787	0.001
	Age	0.687	0.001
	Household registration	0.130	0.002
Personal level	Only child or not	0.478	0.008
	Family economic level	2.489	0.031
	Parental education level	0.081	0.002
	Emotional connection	0.495	0.043
	Concern for children	2.07	0.085
School level	School ranking	0.097	0.021
	Availability of health courses	1.424	0.013
	Intrinsic school climate	0.270	0.002
	Self body image assessment	1.746	0.069
	Sleep time	2.310	1.102