The Effects of Laughter Yoga on Perceived Stress, Positive Psychological Capital, and Exercise Capacity in Lung Cancer Chemotherapy Patients: A Pilot Randomized Trial

Abstract

Background:

Lung cancer is the malignant tumor with the highest morbidity and mortality rate in China. Although chemotherapy is effective in improving clinical symptoms, it causes a variety of acute and chronic side effects, seriously aggravating the psychological stress of patients. Laughter Yoga as a new type of aerobic exercise can effectively reduce stress levels and increase positive mood in patients. This study aimed to examine the effects of laughter yoga on perceived stress, positive psychological capital, and exercise capacity in lung cancer patients.

Methods:

This study was a randomized, single-blind, parallel-group trial. The study enrolled 84 lung cancer chemotherapy patients from a general hospital in central China. These patients were randomly allocated to control and intervention groups (n = 42 per group) after baseline assessments. Patients in the control group received routine care and those in the intervention group received laughter yoga intervention. Perceived stress, positive psychological capital, and exercise capacity were assessed at baseline, immediately post-intervention.

Results:

During the implementation of the study, there were 2 dropouts in each of the intervention and control groups. Ultimately, 80 patients in the control and intervention groups completed the trial. Patients who received laughter yoga intervention had significantly higher scores in positive psychological capital (P < .01, Cohen’s d = 0.692) and exercise capacity (P < .01, Cohen’s d = 0.659). Discernible differences were also observed in perceived stress (P < .01, Cohen’s d = 1.087) between the 2 groups.

Conclusions:

The results of this study suggest that laughter yoga is an effective way and may produce beneficial effects on perceived stress, positive psychological capital and exercise capacity.

Introduction

According to the latest global data, ¹ more than 2.2 million new cases of lung cancer were diagnosed in 2020. About 80% of patients are diagnosed with non-small cell lung cancer (NSCLC). ² Lung cancer is the malignant disease with the highest mortality rate and low survival rate. Because the diagnosis often occurs so late, most patients are unable to receive surgery and have to stabilize the disease with chemotherapy and immunotherapy.^3,4 Lung cancer patients are prone to experience adverse effects during chemotherapy, such as nausea, fatigue and other uncomfortable symptoms.^5,6 The disease itself can also cause serious symptom burden, which may make patients susceptible to negative emotions such as anxiety, depression and increased levels of psychological stress. ⁷ Previous studies have shown that psychological stress not only affects the occurrence and metastasis of tumors but also increases the burden of symptoms in patients.^8,9 Therefore, it is necessary to adopt strategies to reduce psychological stress levels in order to improve the quality of life of patients.

Exercise therapy aims to improve or maintain the physical and mental health of patients. There is considerable evidence of the positive impact of exercise for lung cancer patients, including improving mental health, quality of life and exercise tolerance.^10,11 Laughter yoga as a new, cost-effective aerobic exercise has gradually attracted the attention of researchers. Laughter yoga reduces stress hormone levels by combining unprovoked laughter, yoga breathing and stretching techniques for stress relief. ¹² It has been reported that laughter can reduce the release of serum cortisol and stimulate the brain to think positively.^13,14 Moreover, it has been emphasized that laughter yoga can promote emotional regulation and homeostasis by stimulating endorphin secretion. ¹⁵ A randomized control trial with gynecological cancer patients found that laughter yoga has a beneficial effect on stress, depression and functional well-being. ¹⁶ Similarly, the results of the study by Morishima et al ¹⁷ showed that the health and activity of cancer patients were improved after 12 weeks of laughter yoga intervention. Currently, most research have come from breast or mixed cancer patients.^18,19 Studies reporting laughter yoga intervention in lung cancer patients undergoing chemotherapy are sparse and limited. Therefore, we conducted a randomized controlled trial to examine the effectiveness of laughter yoga in patients undergoing chemotherapy for lung cancer. We hypothesized that the implementation of the laughter yoga intervention would reduce stress levels and increase positive psychological capital, exercise capacity compared to the control group.

Materials and Methods

Study Design and Settings

This was a single-center, randomized controlled trial with a 1:1 parallel-group design. The study was conducted at a general hospital in central China, from July 2021 to December 2021.

Ethical Considerations

This study was approved by the University Ethics Committee (ZZUIRB: 2021-148). All participants were fully informed of the purpose, procedures, risks, and benefits of the study and obtained informed consent before participating in the study.

Participants

All participants were recruited from the respiratory department of a general hospital in central China. Inclusion criteria were as follows: (a) patients diagnosed with NSCLC; (b) having received chemotherapy treatment; (c) age older than 18 years; (d) having a score of >29 on the Chinese Perceived Stress Scale (CPSS); (e) having a score of ≤1 on Eastern Cooperative Oncology Group (ECOG); (f) an estimated life expectancy of at least 6 months; and (g) having agreed to participate in this study. Exclusion criteria were: (a) having received surgical treatment; (b) having diagnosed with psychiatric disorders; and (c) having severe dysfunction or other malignancies.

Sample Size and Randomization

The sample size was calculated using G*Power 3.1.9.2 based on our pilot data of CPSS, with an α .05 (2-sided) level of significance, power of 90%. Therefore, the minimum sample size was 56. Concealed allocation was maintained due to the research assistant who was not involved in the study using a computer randomization program (https://www.suijidaquan.com/) to perform the randomization sequence. The patients who met the inclusion criteria were randomly allocated to 2 groups on a 1:1 basis. The fact that the intervention implementers received extensive training in laughter yoga meant that blinding of them was not possible. However, data collection and statistical analysis were done by different team members to reduce the risk of bias.

Application

Control group

Participants in the control group received routine treatment, education and follow-up provided by the nurses. Routine education is as follows: (a) admission and discharge instructions; (b) information about lung cancer, such as etiology, chemotherapy side effects and ways of coping; (c) dietary management, for instance food choices during chemotherapy and intermittent periods; (d) general principles of physical activity. In addition, weekly follow-up phone calls were conducted where patients can request health counseling for their situation.

Intervention group

Laughter Yoga intervention was implemented in the intervention group, in addition to the routine care and health education described above. The Laughter Yoga program was developed by the research team and respiratory physicians, clinical nursing specialists, and professional yoga teachers. Lung cancer patients undergoing chemotherapy are hospitalized for approximately 10 days per chemotherapy cycle. Therefore, participants allocated to the intervention group received 3 sessions of laughter yoga intervention from the second day of admission for each chemotherapy. The participants were taught in small groups of 6 to 8 by the interveners in a multi-function room. The total of 12 sessions lasted 2 months, and each session was approximately 30 to 40 minutes. Each session included 3 parts: childish games, meditation and relaxation, laughter yoga practice. The first 2 parts in each session are the same, but the laughter yoga practices are different. The parts of the laughter yoga session are described as follows.

Part 1 Childish games (5 minutes): Before starting the exercise, childish games were used to reduce the feeling of alienation between the participants and facilitate subsequent laughter training. Such as “You draw and I guess.” Participants were encouraged to engage in the game enthusiastically like a child, and were given praise to strengthen confidence.

Part 2 Meditation relaxation (10 minutes): Participants were asked to choose their preferred position (sitting or standing), close the eyes, imagine good things in life to soothing music, and then focus on the breathing. After deep inspiration, they were to hold on for 6 to 8 seconds and exhale slowly, imagining that oxygen fills the body and flows within the bloodstream. Finally, they would relax each part of the body in turn.

Part 3 Laughter yoga practice (15 minutes): In this part, patients were to rhythmically move the arms, shoulders, head, and neck. Hands are kept parallel, fingertips and palms touch each other. Then slap finger to finger and follow the rhythm with “hou ha.” Participants look at each other with a smile. This was followed by practicing laughing, which is raised by doing only laughter exercises for no reason, such as imitating robots, lions, greeting, complimenting each other, hugging, saying goodbye, looking at photos. Table 1 shows the specific laughter yoga practice content for each session.

Table 1.

Twelve-Session Laughter Yoga Practice Content.

Sessions	Laughter yoga practice
1	Greet laughter Extend your hand to shake someone’s hand while laughing out loud. Be sure to make eye contact and imagine yourself meeting an old friend. If practicing alone, try doing it in front of a mirror. Shake milk laughter Stretch out your hands, make a fist to simulate grasping the bottle, and then shake your upper body to the left and right once each, while making an “ee-ya” sound. Then lean back and make a movement to drink the milk. Bow and arrow laughter Make a bow-and-arrow motion with both hands, keeping the “bow” hand still and opening the “string” hand three times with varying degrees of force, while making a rhythmic “ee-ya” sound. Finally, open your hands, tilt your head back, and laugh. The lion sticks out its tongue laughter Hold out your hands, spread your fingers wide, and mimic a lion’s teeth and claws in front of your chest. Make your mouth as big as possible, stick out your tongue, widen your eyes, and make a “ha-ha-ha” laugh.
2	Mutual praise laughter Stick out your thumb and point to someone else as a compliment. Then point to yourself, which means “We’re all good,” and laugh as you point. Argumentative Laughter Hold out one finger to someone while smiling, and laugh. Enjoy the photos laughter Pretend to see a beautiful picture of yourself and laugh. Hold up one hand, then the other, gaze at your eyes for a few seconds and let out a “ha-ha-ha” laugh. Learn lessons laughter Put your right hand on your head to symbolize learning the lessons of others; then put your left hand on your head to symbolize learning your own lessons. Empty pockets laughter The hands make a gesture of emptying their pockets, indicating that they are penniless while laughing.
3	Can’t open the engine laughter Half squatting to simulate sitting in the driver’s seat of a car, pretending to have a key in the right hand, simulating the action of unlocking the door with the key, and rhythmically making the sound “keda-keda.” After repeating the action 3 times, the car starts, and very happily lets out a “ha-ha-ha” laugh and joggles with both hands pretending to hold the steering wheel. Hear the jokes laughter Pretend to hear someone tell a joke, pretend to cover your mouth with one hand, and lean forward and backward. Repeat the movement 3 times. Wipe glass laughter Pretend that there is a dirty glass in front of you, stretch out and then make the action of holding a rag. The left and right hands take turns to wipe the window up and down, and huff and puff at the glass. The body moves with the movement, and the range increases from small to large, and then laugh “ha-ha-ha.” Robot laughter Imagine yourself as a robot, moving your limbs and turning your head stiffly from side to side. Then simulate the robot’s clumsy running movements, followed by a “hahaha” laugh.
4	Get free laughter Imagine yourself being bound, and then struggling all over. Ecstatic laughter after breaking free suddenly. Flower blossom laughter Pretend you are an unbloomed flower and start by half squatting, clasping your hands together in front of your chest, and stretching your arms upward as they drive your hands upward. Then the body slowly changes from a squatting position to a standing position, and finally opens the arms upward completely, looks up, and laughs ha-ha-ha at the top of the head. Body lotion laughter Pretend to hold a bottle of body lotion in one hand, pouring it into the other and making a “plopping” sound. Then wipe the body lotion from proximal to distal, from top to bottom, and laugh “ha-ha-ha.” Gradual laughter Everyone as close as possible, let the arm by the arm. Extend the right palm and spread the five fingers upwards, then bend the right fingers in turn with the left hand. Starting with the little finger, laugh as you bend and gradually increase your laughter, laughing the loudest when you reach the thumb. Switch to your left palm and do the same.
5	Keep a secret laughter Pretend to hear a big secret and make a surprised face with your eyes wide open and your mouth covered. Then put a finger to your mouth and make a “shh-shh” sound, followed by a “ha-ha-ha” laugh. Get burned laughter Pretend you are drinking a cup of very hot water. Stick out your tongue, fan your hand over your scalded tongue, and then laugh out loud. Foot hits a rock laughter With one foot up, one hand picks up the foot touched by the “stone,” jumping in place twice, and making a “hissing” sound. Followed by a “ha-ha-ha” laugh. Race running laughter Crouch or stand with your feet in a front and back position and your limbs in a starting action. Then suddenly run two steps forward to make the first person to cross the line. Raise both upper limbs upwards in a victory gesture and laugh “ha-ha-ha.”
6	Hug laughter Try to be as physical as possible with others when you are comfortable with each other, shaking hands or hugging and laughing out loud. Say goodbye laughter Smiling and waving goodbye to each other. And happily agreed to meet again.
7, 9, 11	Greet laughter, shake milk laughter, bow and arrow laughter, the lion sticks out its tongue laughter, can’t open the engine laughter, hear the jokes laughter, wipe glass laughter, robot laughter, get free laughter, flower blossom laughter, hug laughter, say goodbye laughter.
8, 10, 12	Mutual praise laughter, argumentative Laughter, enjoy the photos laughter, learn lessons laughter, empty pockets laughter, body lotion laughter, gradual laughter, keep a secret laughter, get burned laughter, foot hits a rock laughter, race running laughter, hug laughter, say goodbye laughter.

The seventh through twelfth sessions are comprehensive exercises that focus on reviewing previously learned laughter movements.

After learning the laughter yoga skills before discharge, participants were asked to practice laughter yoga twice a week for about 30 minutes between chemotherapy cycles. The practice included meditation, relaxation and laughter yoga practice. Participants could practice 4 to 6 laughter movements of their choice, repeating each movement 1 to 2 times. At the end of each exercise patients recorded the time and feeling of the exercise in the booklet. Meanwhile, the researcher followed up with weekly phone calls to know the participants ' home practice, and resolved any confusion in the practice process.

Quality Assurance of Intervention

Interventions were completed by the principal researcher and 2 research assistants. Prior to the start of the intervention, the research team members received 2 weeks of training from a professional yoga teacher with a laughter yoga training qualification. The training includes an introduction to the concepts and benefits of laughter yoga, and learning the essentials of the poses. The content and related materials for each session are discussed and reviewed by team members. In order to ensure the fidelity, each participant in the intervention group received a booklet to record the time and feelings of laughter yoga practice during the intervention period.

Outcome Assessment

Personal Information Form

The personal information form was designed by the researcher according to the purpose of the study and consists of socio-demographic information (ie, age, education level, marital status, religion, economic conditions) and disease (ie, disease staging, pathological type, and other disease-related information).

Chinese Perceived Stress Scale

The stress was measured using the Chinese Perceived Stress Scale (CPSS), which was developed by Cohen et al in 1983. ²⁰ It consists of 2 dimensions, tension (7 items) and loss of control (7 items), for a total of 14 items, rated on a 5-point Likert scale from 0 (never) to 5 (always). The score ranged from 0 to 56 with higher scores indicating higher levels of stress perception. The internal consistency coefficient of the scale is 0.84.

Positive Psychological Capital Questionnaire

The level of positive psychological status was evaluated using the Positive Psychological Capital Questionnaire (PPQ) developed by Zhang et al ²¹ The questionnaire has 26 items with 4 dimensions including self-efficacy (7 items), resilience (7 items), hope (6 items), and optimism (6 items). It rated on a 7-point Likert scale (1, completely inconsistent; 7, completely consistent). A higher score indicated the better the positive mental state. Cronbach’s α for the questionnaire was 0.90.

Six-Minute Walk Test

According to the American Thoracic Society guidelines. ²² patients were asked to walk quickly back and forth in a 20 m long straight corridor. After 6 minutes, the distance was recorded. The test will be suspended if the patient experiences physical exhaustion or other serious discomfort during the procedure. Two tests were conducted in total, with an interval of more than 30 minutes, and the better one selected as the final result. 6-minute walk test (6 MWT) can assess exercise capacity, and is simple and low-cost.

Statistical Analysis

IBM SPSS24.0 was used for statistical analysis. Appropriate descriptive statistics were used to summarize the characteristics of the participants. The Kolmogorov-Smirnov test was used to assess the data normality. Normally distributed data were shown as mean and SD, nonnormal data were expressed as median and the interquartile range. The Wilcoxon rank sum test, χ² test, or Fisher’s exact test was employed in the characteristics of the participants between the 2 groups at baseline, such as social-demographic and clinical profiles. The independent groups t test or the Mann-Whitney U test was used to compare the scores of CPSS, PPQ, and 6-MWT between the intervention and control groups. The level of significance was set at a P value of .05.

Results

A total of 84 participants were screened and randomly assigned to the control (n = 42) and intervention (n = 42) groups. At the end of the study, 80 participants were included in the final analysis, with 40 participants in each group. Figure 1 presents a CONSORT flow chart.

Figure 1.

CONSORT flow diagram.

In this study, there were 80 participants, 40 in the control group and 40 in the intervention group. No significant differences existed for demographic characteristics between the 2 groups (Table 2).

Table 2.

Sociodemographics and Clinical Characteristics of the Participants (N = 80).

Variables	Control group (n = 40)	Intervention group (n = 40)	P
Gender
Male	32 (80.0)	30 (75.0)	.592 a
Female	8 (20.0)	10 (25.0)
Age
18-40	5 (12.5)	8 (20.0)	.877 c
41-60	18 (45.0)	13 (32.5)
>60	17 (42.5)	19 (47.5)
Education level
Primary	26 (65.0)	19 (47.5)	.098 c
Junior	6 (15.0)	6 (15.0)
Senior	4 (10.0)	9 (22.5)
University	4 (10.0)	6 (15.0)
Marital status
Single	4 (10.0)	5 (12.5)	.953 b
Married	28 (70.0)	26 (65.0)
Widowed	7 (17.5)	7 (17.5)
Divorced	1 (2.5)	2 (5.0)
Religion
Not have	34 (85.0)	35 (87.5)	.745 a
Have	6 (15.0)	5 (12.5)
Monthly family income, RMB
<2000	13 (32.5)	20 (50.0)	.122 c
2000-4000	17 (42.5)	14 (35.0)
4000-6000	8 (20.0)	3 (7.5)
>6000	20 (5.0)	3 (7.5)
Residence
Countryside or town	23 (57.5)	27 (67.5)	.356 a
City	17 (42.5)	13 (32.5)
Other diseases
Yes	18 (45.0)	22 (55.0)	.371 a
No	22 (55.0)	18 (45.0)
Stage
I	1 (2.5)	1 (2.5)	.776 c
II	6 (15.0)	9 (22.5)
III	23 (57.5)	19 (47.5)
IV	10 (25.0)	11 (27.5)
Chemotherapy course (times)
1-3	32 (80.0)	31 (77.5)	.785 a
4-6	8 (20.0)	9 (22.5)

^aχ² test.

^bFisher’s exact test.

^cWilcoxon rank sum test.

As shown in Table 3, there was no significant difference between the 2 groups regarding subscales or the overall CPSS score before the intervention (P > .05). After the intervention, the intervention group’s CPSS score decreased significantly. The difference between the 2 groups was significant, with a large effect size (t = −4.863, P < .001, Cohen’s d = 1.087).

Table 3.

Description of the CPSS Scale Among the Intervention and Control Groups at Pre and Post of the Laughter Yoga Intervention.

Indicators	Time	Control group	Intervention group	t	P	Cohen’s d
Tension	Pre	21.78 ± 2.44	21.55 ± 2.81	−0.382	.703	-
	Post	21.88 ± 2.31	19.43 ± 2.87	−4.203	<.001	0.941
Loss of control	Pre	22.38 ± 2.61	22.18 ± 2.47	−0.352	.726	-
	Post	22.33 ± 1.97	19.95 ± 2.93	−4.261	<.001	0.953
Total score	Pre	44.15 ± 4.60	43.72 ± 4.73	−0.407	.988	-
	Post	44.20 ± 3.87	39.55 ± 4.65	−4.863	<.001	1.087

Table 4 shows the changes in scores on the PPQ in the 2 groups. There was no statistical difference in PPQ score between the 2 groups before intervention (P > .05). The results showed that the differences between the intervention and control groups were statistically significant in all dimensions and overall scores, except for the resilience score, with large effect sizes (t = 3.094, P < .01, Cohen’s d = 0.692).

Table 4.

Description of the PPQ Scale Among the Intervention and Control Groups at Pre and Post of the Laughter Yoga Intervention.

Indicators	Time	Control Group	Intervention group	t	P	Cohen’s d
Self-efficacy	Pre	20.45 ± 8.08	20.83 ± 9.11	0.195	.846	-
	Post	20.78 ± 8.24	25.23 ± 6.42	2.695	.009	0.603
Resilience	Pre	29.50 ± 3.52	28.55 ± 4.13	−1.108	.271	-
	Post	29.02 ± 4.12	29.95 ± 3.50	1.082	.283	-
Hope	Pre	19.93 ± 6.21	19.88 ± 6.91	3.606	.973	-
	Post	19.80 ± 6.41	24.55 ± 5.32	2.947	.001	0.806
Optimism	Pre	22.35 ± 4.45	22.53 ± 4.55	0.174	.862	-
	Post	23.23 ± 5.85	25.93 ± 4.93	2.233	.028	0.500
Total score	Pre	92.23 ± 18.40	91.78 ± 21.52	−0.101	.920	-
	Post	92.83 ± 21.17	105.65 ± 15.47	3.094	.003	0.692

There was no significant difference in 6-MWT between the 2 groups before the intervention (P > .05). However, after the laughter yoga intervention, the difference between the 2 groups was statistically significant (t = 2.947, P < .01), with a large effect size (Cohen’s d = 0.659) (Table 5).

Table 5.

Description of the 6-MWT Among the Intervention and Control Groups at Pre and Post of the Laughter Yoga Intervention.

Indicators	Time	Control group	Intervention group	t	P	Cohen’s d
6-MWT	Pre	421.30 ± 37.78	421.43 ± 37.06	0.015	.988	-
	Post	402.35 ± 35.91	426.08 ± 36.10	2.947	.004	0.659

Discussion

This study examined the effects of laughter yoga on perceived stress, positive psychological capital, and exercise capacity of lung cancer patients receiving chemotherapy.

The study showed that after laughter yoga, perceived stress levels decreased in the patients in the intervention group compared with the control group. Similar findings were reported in previous studies. ²³ In a study in Iran, the findings found that laughter yoga they applied to cancer patients was effective in improving emotional and psychological issues. ¹⁸ Compared with yoga, laughter yoga is a new form of aerobic exercise that incorporates the practice of simulated laughter. ²⁴ Many studies have shown that laughter can have an impact on emotional, psychological and other aspects.^25,26 Simulated laughter exercise can reduce the release of neuroendocrine and stress hormones, reduce serum cortisol levels and thus relieve patients’ stress perception levels.^13,27 As lung cancer patients experience greater psychological stress during disease treatment, they are prone to denial and self-doubt, which can increase feelings of shame. ²⁸ Studies have shown that shame can increase cortisol.^29,30 During the intervention, participants’ shared experience of laughter reduces shame. This may be another explanation for the reduced stress levels of participants. In addition, the deep breathing in yoga also helps to activate the parasympathetic system and reduce the activity of the sympathetic system to minimize existing psychological stress.^31,32 In this study, patients were organized together for laughter yoga practice, which helped to improve emotional communication, information sharing, and spiritual support. This will not only increase the patients’ positive perception of laughter yoga, but will also improve their compliance with the exercise.

The present study showed that intervention group had significantly increased positive psychological capital compared with the control group. A comparison of our results with other studies showed similarities in the effects of laughter therapy has a positive impact on mental health.^33,34 In a study conducted by Moon et al ³⁵ with terminally ill cancer patients, after laughter therapy, there was a significant increase in positive feeling. Simulated laughter can promote the release of dopamine, which produces a sense of pleasure. ³⁶ Simultaneously, laughter practice is also beneficial to the delivery of negative emotions and improve the positive experience. Moreover, a previous study showed that good social support can maintain the positive psychological experience of patients. ³⁷ In this study, group intervention as a form of social support helped to improve the patients’ perceived information and emotional support. Therefore, laughter yoga is an effective method that can be used to increase patients’ positive psychological experience.

The assessment of 6-MWT is important in lung cancer patients because it can effectively reflect the exercise level and the overall functional status of individuals objectively. ³⁸ Our findings showed that laughter yoga can improve the exercise capacity of patients. A possible explanation for the change in exercise capacity could be that the patients in this study relieved their fatigue. Laughter has many benefits. Laughter can stimulate the coordinated movement of facial and abdominal muscles, resulting in a reduction in muscle tension, which helps to relieve fatigue.^39,40 This is consistent with the intervention results by Yeon et al ⁴¹ in patients with gastrointestinal cancer. In addition, deep breathing exercises can expand the thorax, promote gas exchange and increase lung capacity. ⁴² The improvement in the patient’s respiratory function helps to improve activity tolerance. Another possible explanation for this increase may be the improvement of immune function. In the literature, it was emphasized that laughing can strengthen the immune system. ²⁷ Laughing promotes the production of endorphins, which raise immunity by activating natural killer cells.^43,44 In the study of Sakai et al ⁴⁵ which examined the effects of laughter yoga in cancer patients undergoing surgery or chemotherapy, a conclusion was reached that laughter exercises can significantly improve the immune function of patients. This suggests that laughter yoga is effective in improving the exercise capacity of patients. Although the exercise capacity of the intervention group has improved, the long-term effect of laughter yoga is unclear. Given the exercise capacity is influenced by a variety of factors, a longitudinal study is required to evaluate the long-term effectiveness of laughter yoga.

Limitations

This study had several limitations that need to be considered. First, although laughter yoga seemed to have positive effects, it should be recognized that the study only observed the effects at baseline and after the intervention, so it was not possible to assess the long-term effects of laughter yoga. Future studies should include a longer follow-up period and examine whether laughter yoga has the same effect in improving other aspects, such as quality of life. Second, this study was a single-center trial. The sample size included was small due to a number of factors, which may limit the generalizability of the results to the general population. Third, one of the study inclusion criteria was ECOG ≤ 1; thus, the laughter yoga effects may limited to lung cancer chemotherapy patients who have relatively good physical condition.

Conclusion

Laughter yoga, as a simple aerobic exercise, has many advantages, such as economy and fun. The results of this study indicate that laughter yoga is beneficial to lung cancer chemotherapy patients by reducing the level of perceived stress, increasing psychological capital, exercise capacity. Although the study was conducted in only one hospital, this intervention is worthy of further research and promotion, and further research is needed to study the long-term effects in different populations.