Study Selection
A total of 1628 relevant articles were retrieved from eleven electronic databases. After removing duplicate articles, 1217 articles remained. After reading the titles and abstracts, 1102 articles were excluded. After reading the full texts of the remaining 115 articles, 99 studies were further excluded for the following reasons: insufficient information and data (n=22); no relevant outcomes (n=14); no control group (n=24); not a full article (n=17); and other (n=22). Finally, 16 studies were found to meet the study inclusion criteria and were pooled for meta-analysis[4,9,38-51]. The PRISMA flow diagram is illustrated in Fig. 1.
Fig. 1 about here
Study characteristics
The basic characteristics of the included studies are summarized in Table 1. A total of 1628 subjects in sixteen studies from thirteen Chinese[38-45,47-51] and three English articles[4,9,46] were included in the final analysis. All these studies were conducted in China and published in Chinese and foreign language journals from 2015 to 2021. All participants were undergraduate or graduate students. The studies compared the effects of Qigong exercise with original sports exercise practices, muscle relaxation training or maintaining the original lifestyle without any intervention on the physical and mental health of college students. The intervention time in the Qigong group and the control group was the same, and interventions ranged from 8 weeks to 32 weeks, with most interventions being 12 weeks. All studies reported physical or psychological outcomes. Among them, in terms of psychological indicators, eleven studies evaluated depression by using the self-rating depression scale (SDS)[38,40,47,49], SCL-90 Depression[41-42,48,50-51], center for epidemiologic studies depression scale (CES-D)[45] and hamilton depression scale (HAMD)[44]; eight studies used the self-rating anxiety scale (SAS)[38,47,49] and SCL-90 anxiety[41-42,48,50-51] to assess anxiety, and three studies used the profile of mood states (PMOS)[4,46,48] to assess mood. In the evaluation of physical indicators, seven studies reported vital capacity[4,9,39,41-43,51], five studies used a standing long jump to evaluate lower limb strength[4,39,41-42,51], four studies reported hand grip force levels[4,41-42,51], five studies reported using the Sit-and-Reach test to assess flexibility[4,9,39,41-42], five studies reported using the step test to assess cardiorespiratory endurance[4,9,41-42,51], three studies reported blood pressure[4,9,43], and three studies reported heart rate[4,9,43].
Table 1
Characteristics of the included studies
|
First author, year
|
Age (years)
mean±SD
|
Sample size
|
Intervention
|
Outcome
|
Treatment duration
|
|
QG
|
CG
|
QG
|
CG
|
QG
|
CG
|
|
|
ChengX,44 2016
|
21.1±1.4
|
21.0±1.6
|
15
|
15
|
3×(40-60)min/wk for 12 weeks(Wuqinxi)
|
No intervention
|
HAMD
|
12weeks
|
ChenJ,45 2019
|
NR
|
18
|
18
|
3×60min/wk for 16 weeks(Tai Chi)
|
No intervention
|
CES-D
|
16weeks
|
ChenT,46 2016
|
22.5±2.0
|
21
|
21
|
5×90min/wk for 8 weeks(Baduanjin)
|
Relaxation training
|
POMS
|
8weeks
|
JiaoX,51 2021
|
20.0±1.3
|
40
|
40
|
5×80min/wk for 16weeks(Wuqinxi)
|
5×80min/wk for 16weeks
(Original sports )
|
Vital capacity, Standing long jump, Hand grip force, Step test, SCL-90Depression, SCL- 90 Anxiety
|
16weeks
|
GuoT,50 2021
|
NR
|
NR
|
30
|
30
|
3×45min/wk for 12weeks(Baduanjin)
|
No intervention
|
SCL-90 Depression,
SCL-90 Anxiety
|
12weeks
|
KeX,38 2019
|
19.4±0.5
|
19.5±0.6
|
20
|
17
|
≥5×60min/wk for 10 weeks(Baduanjin)
|
No intervention
|
SDS, SAS
|
10weeks
|
LiM,4 2015
|
20.63±1.03
|
20.92±1.15
|
101
|
105
|
5×60min/wk for 12 weeks(Baduanjin)
|
No intervention
|
Vital capacity, Standing long jump, Hand grip force,
Sit-and-Reach, Step test,
Blood pressure, Heart rate,
POMS
|
12weeks
|
LaiQ,39 2018
|
20.61±1. 06
|
20.54±1. 05
|
30
|
30
|
5×60min/wk for 12 weeks(Baduanjin)
|
No intervention
|
Vital capacity, Standing long jump, Sit-and-Reach
|
12weeks
|
LuoS,49 2021
|
NR
|
157
|
158
|
3×30min/wk for 16weeks(Tai Chi)
|
No intervention
|
SDS, SAS
|
16weeks
|
WangM,40 2020
|
NR
|
30
|
30
|
7×40min/wk for 24weeks(Wuqinxi)
|
No intervention
|
SDS
|
24weeks
|
WeiQ,41 2017
|
NR
|
60
|
60
|
5d×2times/wk for 12weeks(Yijinjing)
|
No intervention
|
Vital capacity, Standing long jump, Hand grip force, Sit-and-Reach, Step test, SCL-90 Depression, SCL-90 Anxiety
|
12weeks
|
WangB,48 2021
|
NR
|
100
|
100
|
≥3×90min/wk for 18weeks(Baduanjin)
|
No intervention
|
POMS, SCL-90 Depression,
SCL-90 Anxiety
|
18weeks
|
YanH,42 2017
|
NR
|
n=50
|
50
|
5d×2times/wk for 12weeks(Baduanjin)
|
No intervention
|
Vital capacity, Standing long jump, Hand grip force, Sit-and-Reach, Step test, SCL-90 Depression,SCL-90 Anxiety
|
12weeks
|
YuanM,43 2017
|
NR
|
12
|
12
|
4×60min/wk for 20weeks(Tai Chi)
|
No intervention
|
Vital capacity, Blood pressure,Heart rate
|
20weeks
|
ZhengG,92015
|
20.7±1.1
|
20.6±1.2
|
95
|
103
|
5×60min/wk for 12weeks(Tai Chi)
|
No intervention
|
Vital capacity, Sit-and-Reach, Step test, Blood pressure, Heart rate
|
12weeks
|
ZhangY,47 2021
|
19-22
|
30
|
30
|
2×90min/wk for 8weeks(Baduanjin)
|
No intervention
|
SDS, SAS
|
8weeks
|
SD:standard deviation;QG: qigong group;CG: control group; NR: not reported; POMS:Profile of mood states;SDS:Self-rating depression scale;SAS:Self-rating anxiety scale;HAMD:Hamilton depression rating scale;CES-D:Center for epidemiologic studies depression scale.
Assessment of risk of bias
All 16 studies reported randomization, but only 3 trials reported randomizing the patients by using statistical software or a random number table to generate randomization sequences[4,9,49]. Two studies mentioned allocation concealment. The allocation sequence was concealed with password access files or kept with a project manager[4,9]. Two studies used blinding and were treated as low-risk studies[4,9], while the remaining 14 studies were rated as high risk because the control group did not receive any intervention measures and were unable to do blindness. Two studies reported dropouts during the clinical study, but all indicated reasons were unlikely to be related to the results[4,9]. Therefore, the risk of bias for incomplete outcome data was assessed as low risk for all studies. Two studies were assessed as low risk with a protocol available[4,9], while the remaining studies were unclear, as there was not enough information to judge. Two studies described the limitations of the study in the discussion section and were therefore rated as high risk[44,46] (Fig. 2).
Fig. 2 about here
Evaluation of physical outcomes
Flexibility
Five RCTs[4, 9, 39, 41-42] analysed the scores of the Sit-and-Reach test as indicators of flexibility, including a total of 684 participants (336 in the Qigong group and 348 in the control group). The pooled results revealed a significant difference for the effect of Qigong exercise on the sit-and-reach index (MD=3.01, 95% CI: 1.21 to 4.81, P=0.001). However, due to the high heterogeneity among the studies (I2=70%) (Fig. 3A), a sensitivity analysis was conducted in which the included studies were excluded one by one. However, no matter which study was removed, the heterogeneity remained high. The Qigong group was also better than the control group (P<0.05).
Cardiorespiratory endurance
The scores of the step test for cardiorespiratory endurance were analysed in five RCTs[4,9,41-42,51] that included a total of 704 participants (346 in the Qigong group and 358 in the control group). Compared to the control group, the results of the meta-analyses showed a significant improvement (MD=3.83, 95% CI: 0.99 to 6.67, P=0.008) in college students with Qigong exercise (Fig. 3B). However, heterogeneity among studies was I2 = 85% and did not obviously change after sensitivity analysis by removing any one of those studies.
Hand grip force
Four RCTs[4,41-42,51] analysed the effect of Qigong interventions on hand grip force levels, including a total of 506 participants (251 in the Qigong group and 255 in the control group). The pooled result showed that the difference was not significantly from that of the control group (SMD=0.08, 95% CI: -0.09 to 0.26, P=0.34, I2=0%) (Fig. 3C).
Standing long jump
The standing long jump scores were analysed in five RCTs[4,39,41-42,51] involving a total of 566 participants (281 in the Qigong group and 285 in the control group). The pooled results showed that compared with the control group, the difference was not statistically significant (SMD=0.16, 95% CI: -0.08 to 0.40, P=0.20, I2=48%) (Fig. 3D).
Fig. 3 about here
Vital capacity
Seven RCTs[4, 9, 39, 41-43,51] reported the vital capacity of 712 participants (350 in the Qigong group and 362 in the control group), and the pooled result showed that compared with the control group, the difference was not statistically significant (SMD=0.11, 95% CI: -0.11 to 0.33 P=0.32, I2=44%) (Fig. 4A).
Systolic blood pressure
Systolic blood pressure scores were analysed in three RCTs[4,9,43] that included a total of 428 participants (208 in the Qigong group and 220 in the control group). Meta-analysis showed that there was no significant difference between the Qigong exercise and control groups (MD =-0.70 95% CI: -3.50 to 2.09, P=0.62, I2=26%) (Fig. 4B).
Diastolic blood pressure
Diastolic blood pressure scores were analysed in three RCTs[4,9,43], including a total of 428 participants (208 in the Qigong group and 220 in the control group). The pooled results showed that compared with the control group, no significant difference was found in the Qigong group (MD=-0.24, 95% CI: -1.91 to 1.42, P=0.77, I2=0%) (Fig. 4C).
Heart rate
Three RCTs[4,9,43] analysed heart rate scores that included a total of 428 participants (208 patients in the Qigong group and 220 in the control group). The pooled result showed that there was no significant difference between the Qigong exercise and control groups (SMD=0.00, 95% CI: -0.19 to 0.19, P=1.00, I2=0%) (Fig. 4D).
Fig. 4 about here
Evaluation of psychological outcomes
Depression
Eleven RCTs[38,40-42,44-45,47-51] analysed the effect of Qigong interventions on depression, including a total of 1098 participants (550 in the Qigong group and 548 in the Control group). The pooled results showed that Qigong significantly reduced depression in college students compared with the control group (SMD=-0.89, 95% CI: -1.17 to -0.61, P<0.00001). However, due to the substantive heterogeneity among the studies (I2=77%) (Fig. 5A), a sensitivity analysis was conducted in which the included studies were excluded one by one. The heterogeneity was significantly reduced (I2=58%) when the study of ChengX et al, 2016, was removed. The Qigong group also had better results than the control group (SMD=-0.75, 95% CI: -0.96 to -0.54, P<0.00001) (suplementary Fig. 1).The funnel plot shows almost bilateral symmetry and is less likely to be influenced by publication bias (Fig. 6).
Fig. 6 about here
Anxiety
Eight RCTs[38,41-42,47-51] analysed the anxiety of 972 participants (487 in the Qigong group and 485 in the Control group). The meta-analysis showed that Qigong exercise significantly relieved anxiety in college students compared with the control group (SMD=-0.78, 95% CI: -1.31 to -0.25, P=0.004) with substantive heterogeneity (I2 = 93%) (Fig. 5B) . The pooled result was changed to an SMD of -0.51 (95% CI -0.67 to -0.35) with low heterogeneity (I2 = 0%, P<0.00001) after sensitivity analysis was conducted by removing LuoS et al, 2021 (suplementary Fig. 2).
Mood
Three RCTs[4,46,48] involving 448 participants (222 in the Qigong group and 226 in the Control group) analysed the effects of Qigong exercise on mood scores. The results of the meta-analysis showed no significant changes between the Qigong exercise and control groups (MD =-7.79, 95% CI: -16.18 to 0.60, P=0.07, I2=93%) (Fig. 5C). The sensitivity analysis by removing studies one by one did not change the result.
Fig. 5 about here