Relationship between physical activity and specific working memory indicators of depressive symptoms in university students

Table 1 Basic information of university students with different depression symptoms, (%)

Demographic indicators	Overall	Without depression	With depression	Comparison among groups
	(n = 143)	(n = 112)	(n = 31)	χ²/t	P value
Gender (male)	47.55	48.21	45.16	0.091	0.763
Age (yr)	19.53 ± 1.149	19.52 ± 1.139	19.58 ± 1.205	0.959	0.789
BMI (kg/m²)	21.483 ± 3.939	21.729 ± 4.039	20.592 ± 3.468	0.245	0.156
Registered household (city)	52.45	58.04	32.26	6.469	0.011a
Only child (yes)	46.15	50.89	29.03	4.669	0.031a
Single-parent family (yes)	9.09	9.82	6.45	0.334	0.564
Average education year of parents (yr)	11.119 ± 3.598	11.371 ± 3.370	10.210 ± 4.260	0.117	0.112
Drinking habit (yes)	20.28	18.75	25.81	0.748	0.387
Smoking habit (yes)	2.10	2.68	0	0.848	0.357
Family relations
Amiable	50.35	53.57	38.71	3.466	0.177
General	47.55	43.75	61.29
Many conflicts	2.10	2.68	0
Study pressure
Easy	22.38	25.89	9.68	7.107	0.029a
General	54.55	55.36	51.61
Difficult	23.08	18.75	38.71
Interpersonal relationship
Good	74.13	83.04	41.94	22.009	< 0.001b
General	23.78	16.07	51.61
Bad	2.10	0.89	6.45
Social activities
> Three times/wk	2.80	1.79	6.45	13.625	0.001b
≤ Three times/wk	83.22	89.29	61.29
Hardly	13.99	8.93	32.26

^aP < 0.05.

^bP < 0.01.

BMI: Body mass index.

Table 2 Differences in working memory among college students with different depressive symptoms (mean ± SD)

Variable	Without depression, (n = 134)	With depression, (n = 31)	F value	P value
VWM accuracy	0.868 ± 0.080	0.762 ± 0.170	50.963	0.002
VWM reaction time	995.18 ± 146.27	913.45 ± 290.846	42.502	0.14
SWM accuracy	0.875 ± 0.084	0.773 ± 0.187	73.121	0.006
SWM reaction time	955.41 ± 168.20	880.81 ± 249.87	10.484	0.125

VWM: Verbal working memory; SWM: spatial working memory.

Table 3 Characteristics of working memory of university students with different exercise intensity

Variable	Overall	Different intensity			F value	P value	Multiple comparisons
	(n = 143)	Low (n = 27)	Medium (n = 94)	High (n = 22)			Low vs medium	Low vs high	Medium vs high
Accuracy rate of VWM	0.845 ± 0.114	0.795 ± 0.102	0.849 ± 0.104	0.889±0.048	4.45	0.013	0.028	0.004	0.137
Accuracy rate of SWM	0.853 ± 0.121	0.786 ± 0.171	0.862 ± 0.106	0.894±0.069	6.008	0.003	0.004	0.002	0.241

VWM: Verbal working memory; SWM: Spatial working memory.

Table 4 Characteristics of working memory of university students with different exercise duration.

Variable	Overall	Duration			F value	P value	Multiple comparisons
	(n = 143)	< 30 min (n = 33)	30-59 min (n = 63)	≥ 60 min (n = 47)			Low vs medium	Low vs high	Medium vs high
Accuracy rate of VWM	0.845 ± 0.114	0.808 ± 0.165	0.869 ± 0.084	0.838 ± 0.114	3.344	0.038	0.012	0.243	0.151
Accuracy rate of SWM	0.853 ± 0.121	0.798 ± 0.172	0.874 ± 0.084	0.862 ± 0.111	4.675	0.011	0.003	0.018	0.608

VWM: Verbal working memory; SWM: Spatial working memory.

Table 5 Characteristics of working memory of university students with different exercise frequency

Variable	Overall	Frequency			F value	P value
	(n = 143)	≤ Once/mo (n = 1)	Twice/month-twice/week (n = 103)	≥ Three times/week (n = 39)
Accuracy rate of VWM	0.845 ± 0.114	0.766 ± 0.000	0.840 ± 0.117	0.861 ± 0.114	0.709	0.494
Accuracy rate of SWM	0.853 ± 0.121	0.797 ± 0.000	0.847 ± 0.114	0.870 ± 0.139	0.623	0.538

VWM: Verbal working memory; SWM: Spatial working memory.