Abstract
Aim:
The objectives of this study were to evaluate the responses of overweight college students to two types of Tai Chi intervention programs, to ensure data quality by assessing repeatability and reliability, and to assess changes in variable means after training. Additionally, the study aimed to compare the exercise intensity between the two types of Tai Chi during 30 min of practice.
Methods:
Participants underwent a 2-week Tai Chi intervention program, consisting of 1-h sessions, three times a week. Measurements of heart rate (HR) and energy expenditure were obtained using a Polar heart rate monitor (H10), while flexibility, upper and lower limb strength, balance, and aerobic endurance were measured before and after the intervention. Repeatability was established using Bland-Altman plots, and reliability was assessed using intraclass correlation coefficient (ICC). Between-group variables were compared using independent t-tests, while paired t-tests were used to compare changes within each group between pre- and post-tests in the mean of variables.
Results:
Bland-Altman plots showed good repeatability of pre- and post-test and ICC values for all measured variables ranging from 0.54 to 0.99. There were no significant changes observed in the mean of all measured variables from pre- to post-testing in both groups (p > 0.05). Significant difference was observed in metablic equivalent (MET) value (5.75 ± 0.66 vs. 4.65 ± 0.40) and maximum HR (141.80 ± 10.83 vs. 117.50 ± 10.97) between the two different types of Tai Chi in 30 min of Tai Chi practice (p < 0.001).
Conclusions:
The training and assessments were safe and appropriate for overweight Chinese male college students, and the measurement methods used in the study were reliable. A 2-week Tai Chi training did not result in changes in the mean of variables. The study suggests the possibility of further research under well-designed training programs and close supervision by researchers.
Clinical Trials Registry Identifier ChiCTR2200059427; April 29, 2022.
Introduction
The latest research shows that 22.7% of Chinese students aged 19–22 are overweight or obese, while 8.4% of female students are being overweight or obese poses a major public health threat, 1 affecting various bodily functions and imposing a heavy burden on both individuals and society. 2 Studies suggest that a high incidence of overweight or obesity and lack of physical exercise can lead to an increased risk of chronic diseases, including coronary heart disease, 3 cardiovascular diseases, 4 musculoskeletal diseases, 5 depression, 6 and premature death. 7 These negative impacts can reduce the quality of life and work efficiency, and increase health care costs.
Breakfast enhances physical performance and reduces the risk of overweight and obesity.
Tai Chi is an ancient Chinese practice that combines physical and mental exercises based on the principles of Chinese medicine and martial arts. 12 Its continuous, flowing movements incorporate breathing and mindfulness to promote harmony in mind and body. 13 Tai Chi has been demonstrated to improve risk factors associated with overweight or obesity, such as physical fitness and blood markers, with modern research supporting its health benefits.14,15 However, limited comparative intervention studies have been conducted on traditional and modified Tai Chi, and research has primarily focused on adolescents, middle-aged, and elderly individuals, with a lack of data on overweight college students.
A comparative study on the effects of the newly compiled simplified Bafa Wubu Tai Chi (BW-TC) and Traditional He-style Tai Chi (TH-TC) on overweight and obese individuals fills a research gap and highlights areas for future investigation. 16 To this end, we have developed two Tai Chi intervention plans for overweight college students. It is important for researchers to assess the feasibility, repeatability, and reliability of the intervention plans, as well as the feedback from participants and the changes in relevant assessment parameters resulting from applying the new research procedures to new subjects.
This report studied how overweight male college students in China responded to two different Tai Chi training programs. Researcher monitored the data quality and measured changes in assessment parameters after 2 weeks of training. The study aimed to evaluate the effectiveness of the two Tai Chi programs and provide information for further research. The study could also serve as a research template for Tai Chi training programs for overweight students and feedback was collected from students and coaches to improve the program. It was a pilot study with no similar prior experience.
Materials and Methods
Study design
In this randomized controlled study, participants agreed to participate in a 2-week Tai Chi training program, with baseline measurements taken for each group including basic characteristics such as height, weight, age, and body mass index (BMI). The two different Tai Chi groups participated in different training programs, and flexibility, strength, balance, and endurance were measured before and after the training period. The study was conducted over 2 weeks from September 27 to October 11, 2021, and exercise intensity was also measured during the training period. This pilot study protocol was approved by the Khon Kaen University Ethical Committee for Human Research (HE642132), and the trial was registered with the Chinese Clinical Trial Registry (registration no. ChiCTR2200059427) and carried out in accordance with the Declaration of Helsinki. All participants signed written informed consent in the study.
Participants
In this pilot study, 43 male college students were screened for eligibility from Jiaozuo Normal College in China, and 20 eligible participants were randomly assigned to either the BW-TC group (n = 10) or the TH-TC group (n = 10). Inclusion criteria for participants included being 18–23 years old, male college students in their first or second year, and having a BMI of 24–27.9. Exclusion criteria were regular long-term Tai Chi athletes, being a member of any sports association, and having severe cardiovascular or musculoskeletal system disease. Figure 1 outlines the entire intervention process and the effects of progress in this pilot study according to the Consolidated Standards for Reporting Trials criteria.

Consolidated Standards for Reporting Trials (CONSORT) flow diagram.
Intervention
The trial comprised of two groups, the BW-TC group, which practiced simplified BW-TC,
17
and the TH-TC group, which practiced traditional He-style Tai Chi. Both groups received a 2-week intervention, consisting of three sessions per week, after class hours on Mondays, Wednesdays, and Fridays from 5:30 to 6:30
Outcome measurements
Outcome measurements in this study included baseline characteristics such as height, weight, age, and BMI, which were measured using a Bingyu RGZ-160 height–weight scale in centimeters and kilograms. 18 HR and energy expenditure were measured during 30-min Tai Chi sessions using Polar heart rate monitors (H10) to assess exercise intensity. 19 Flexibility was measured using the sit and reach test, which involved participants bending forward and pushing a test cursor with their fingertips while sitting on a mat with legs straight and feet together. 20 The distance reached was recorded in centimeters, and the test was repeated twice. Upper limb strength was assessed using an electronic grip strength tester, with participants standing naturally with their dominant hand holding the device. 21 Lower limb strength was measured using the wall squat test, with participants holding a right angle and their thighs parallel to the floor while leaning against a vertical wall. 22 Total time held was recorded, and the test was repeated twice. Balance was assessed using the Balance Error Scoring System (BESS) and the Y Balance Test (YBT). The BESS required participants to maintain different postures with their eyes closed and hands on hips for 20 sec, with errors recorded. 23 The YBT required participants to stand on one foot and push a test board in different directions as far as possible without support, with the farthest distance recorded. 24 Each test was repeated twice. Finally, aerobic endurance was assessed using the six-minute walk test (6MWT), which required participants to walk around a 30-m trail within 6 min while the longest distance walked was recorded. 25 All these tests were conducted at baseline and after 2 weeks of Tai Chi training.
Statistical analysis
All data were performed by SPSS 26.0 (IBM Corp., Armonk, USA). The Shapiro–Wilk test checks for consistency and normal distribution of data. The Bland-Altman technique was used to analyze the repeatability for both the BW-TC and the TH-TC groups between the 2-week pre- and post-test. 26 The intraclass correlation coefficient (ICC) was used to assess the reliability of the data within the two groups. Independent t-test was used to compare the different between two groups variables at baseline and the difference in intensity of exercise for 30 min between the BW-TC group and the TH-TC group, paired t-tests were used to compare the changes in the mean of the within-group pre- and post-test variables.
Results
All results were analyzed based on supplementary data S1. Based on the Shapiro–Wilk normal distribution test, all data had a normal distribution (p > 0.05). The demographic information of all participants is displayed in Table 1, which shows no significant differences in age, height, weight, and BMI between the two Tai Chi groups at the baseline. Additionally, the independent samples t-test revealed no significant difference between the two groups before training in all variables (p > 0.05).
Comparison of Groups in Terms of Demographic Data at Baseline, Mean ± Standard Deviation and p-Values from Independent Samples Test Comparison of All Variables Between Groups Before Intervention
Independent t-test was used for all other group comparisons.
6MWT, six-minute walk test; BESS, Balance Error Scoring System; BMI, body mass index; BW-TCG, Bafa Wubu Tai Chi group; cm, centimeter; kg, kilogram; m, meter; sec, second; SD, standard deviation; TH-TCG, Traditional He-style Tai Chi group; YBT, Y Balance Test.
Repeatability, reliability, and the change of pre- and post-test in BW-TC group and TH-TC group
The results showed that the means and standard deviations of the BW-TC and TH-TC groups were similar before and after the test, indicating that the 2-week Tai Chi intervention had limited effects on these variables. Table 2 presents the statistical results of the BW-TC and TH-TC groups, including mean (±standard deviation), mean difference (MD; △), bias (LOA), ICC, and t and p values from the paired t-test. The means and standard deviations of all measured variables were similar from pre- to post-test in both groups. No significant differences were found for any variables (p > 0.05). This is consistent with the short intervention period of the study, which may not be sufficient to produce significant physiological changes. ICC values for all variables fell within the range of 0.54–0.99 for both groups, indicating good reliability. These high ICC values confirm that flexibility, upper limb strength, lower limb strength, or other physical fitness indicators have high repeatability, further verifying the reliability of these measurement tools in overweight college students.
Mean ± Standard Deviation, Mean Differences (△) Between Pre- and Post-test, t and p Values from Paired t-Tests Comparison Within Group of All Variables in the Bafa Wubu Tai Chi Group (BW-TCG) and Traditional He-Style Tai Chi Group (TH-TCG)
6MWT, six-minute walk test; BESS, Balance Error Scoring System; cm, centimeter; kg, kilogram; m, meter; sec, second; YBT, Y Balance Test; LOA, limits of agreement.
The Bland-Altman plot also demonstrated good repeatability between the before and after measurements. Figure 2 shows 6 out of the 28 Bland-Altman plots, showing good repeatability in pre- and post-measurements. In the BW-TC group, the MD in flexibility was −0.20 cm with a precise interval of −3.51 to 3.11 cm, while the MD in upper limb strength and lower limb strength was 0.55 kg and 0.20 s, respectively. Similarly, in the TH-TC group, the MD in flexibility was −0.50 cm with a precise interval of −3.15 to 2.15 cm, while the MD in upper limb strength and lower limb strength was 0.04 kg and −0.90 s, respectively. These results demonstrated that although the 2-week intervention period did not produce significant changes, the measurement results had high repeatability and reliability.

Examples of six Bland-Altman plots of BW-TC group and TH-TC group (flexibility, upper limb strength, and lower limb strength): mean (dark line) is the average of the difference in a measured variable (pre-test–post-test). Mean ± 1.96 × SD (dashed lines) is most of the difference from the mean which is derived from the average of differences in the measured variable (MD) ± 1.96 × standard deviation of the mean difference. For example, in the flexibility of the BW-TC group, mean = 0.02 cm and SD = 1.69 cm. Mean − 1.96 × SD = −3.15 cm and mean + 1.96 × SD = 3.11 cm. BW-TC, Bafa Wubu Tai Chi; MD, mean difference; SD, standard deviation; TH-TC, Traditional He-style Tai Chi.
Intensity of the two types of Tai Chi
Table 3 shows the data of statistics that Polar H10 measured the max HR, min HR, average HR, HR after 30 min of exercise, energy expenditure (Kcal), and exercise intensity (METs). TH-TC group compared with BW-TC group in max HR (141.80 ± 10.83 > 117.50 ± 10.97), average HR (115.30 ± 7.21 > 98.80 ± 10.77), HR after 30 min of exercise (119.30 ± 13.71 > 100.70 ± 10.54), energy expenditure (Kcal) (222.30 ± 22.84 > 184.10 ± 13.41) and exercise intensity (METs) (5.75 ± 0.66 > 4.65 ± 0.40), the equal means were greater than the BW-TC group for all parameters, with a statistically significant difference (p < 0.001).
Maximum HR, Minimal HR, Average HR, End of HR, Calories, and Exercise Intensity in 30 Min During BW-TC and TH-TC
30-HR, heart rate after 30 min of practice; Bpm, Beat per minute; BW-TCG, Bafa Wubu Tai Chi group; HR, heart rate; SD, standard deviation; TH-TCG, Traditional He-style Tai Chi group.
Discussion
In this pilot study, we evaluated the exercise intensity and responses of overweight male college students to two different types of Tai Chi training programs over 2 weeks using suitable testing protocols and data quality controls. This study represents the first attempt to assess the impact of Tai Chi on this particular population. Our findings indicate that the Tai Chi training programs were well-received and safe, with good repeatability and reliability of the measured variables. We observed significant differences in exercise intensity between the two types of Tai Chi, but no significant changes in measured variables pre- to post-test.
Response
During this study, we aimed to evaluate the response of overweight male college students to two different Tai Chi training programs. The subjective feedback obtained from the participants indicated that they performed well during the 2-week practice, completing all prescribed tasks under the guidance of qualified coaches. The participants provided feedback and received technical guidance to adjust movement deviation. No discomfort or injury was observed during the 2-week Tai Chi training sessions, and no subjects withdrew from the program.
Repeatability, reliability, and change
The repeatability and reliability of flexibility, upper limb strength, lower limb strength, BESS, YBT, and 6MWT measurements have been validated in various populations in previous studies. 27 However, this is the first study to measure the repeatability and reliability of these variables in overweight male college students. The Bland-Altman plot and ICC demonstrated good repeatability and reliability in both the BW-TC group (ICC 0.58–0.99) and TH-TC group (ICC 0.54–0.99). The ICC values in this study ranged from 0.54 to 0.99, indicating good repeatability of the measurements for each physical fitness indicator before and after testing. Specifically, for flexibility, strength, and balance, higher ICC values (e.g., >0.75) suggest a high level of consistency between measurements at different time points. This means that even with a short intervention period, the measurement tools were still able to accurately reflect the participants’ physical fitness. Relatively lower ICC values (such as 0.54) may indicate some variability in certain measurements, which could be due to individual differences among participants or external factors, but the overall reliability remains acceptable. The Bland-Altman plot further confirmed the consistency of the measurements before and after testing. For physical fitness variables such as flexibility and strength in the BW-TC and TH-TC groups, the MDs were within a reasonable range, and most data points were within the 95% limits of agreement. This suggests that there were no significant systematic biases between the pre- and post-measurements, and the measurement errors were within an acceptable range. Even with a short intervention period, the tools were still able to reliably and accurately capture the participants’ physical fitness changes. These findings provide additional support for the reliability of these evaluation variables, which are frequently used in Tai Chi intervention research on the elderly. 28 Despite potential factors such as study population, environment, or human factors affecting these variables, the observed repeatability and reliability in this study are acceptable and consistent with previous research results.
The baseline evaluation parameters of the two different types of Tai Chi groups were similar. Furthermore, the mean and standard deviation of all variables before and after the training were similar in the BW-TC group and the TH-TC group from pre- to post-test. The MD was very small, and correlated t-tests showed that there were no statistical differences. The analysis of the results of this pilot study indicated that there was no significant difference in the mean of the measured variables between the two groups after 2 weeks of Tai Chi training. Previous studies have not found that a 2-week Tai Chi intervention can produce changes in flexibility, upper and lower limb strength, balance, and aerobic endurance, but 6 weeks, 29 8 weeks, 30 or 12 weeks 31 program duration. Results from these studies have proven that short-term Tai Chi intervention was ineffective, as reported in our 2-week Tai Chi intervention. Exercise adaptations involve a complex set of physiological mechanisms, such as increased muscle strength, improved joint mobility, and increased cardiorespiratory endurance, and these effects often require weeks or even months of continued training to manifest. 32 Additionally, the participants were overweight college students with relatively low baseline fitness levels. Individuals with poor fitness typically require more time to adapt to exercise, making it difficult to observe significant improvements in the short term. 33 For these individuals, improvements in flexibility, strength, and cardiovascular endurance often take longer to manifest, which may have limited our ability to observe significant changes within the 2-week intervention period.
Intensity difference
Tai Chi exercise intensity is determined by various factors, such as type, practice method, posture, and duration. According to the model developed by Pate RR, exercises with an average MET value between 3 and 6 are considered to be of medium intensity. 17 The average MET values of BW-TC and TH-TC after 30 min of practice were 4.65 and 5.75, respectively, indicating that both types of Tai Chi can be considered medium-intensity exercises. A previous report found that the MET value for BW-TC after a 4-minute practice session was low-intensity exercise. However, after practicing BW-TC continuously for 30 min, its exercise intensity was found to be low to medium based on the MET value. Currently, research on the exercise intensity of TH-TC is lacking. Nonetheless, some scholars have reported that classical Yang Style Tai Chi is a medium-intensity exercise, 34 which is consistent with our findings since TH-TC is a classical Tai Chi and shares similar practice methods, ranges, and times to complete the entire set of exercises with classical Yang Style Tai Chi.
According to the American Heart Association’s criteria for target HR and exercise intensity, moderate-intensity exercise has a target HR of 50%–70% of the maximum HR. 35 In our study, we found that the average maximum HRs of overweight male college students with an average age of 18, practicing TH-TC and BW-TC, were 141.80 and 117.50 bpm (beats per minute), respectively. These results fall within the range of moderate-intensity exercise, indicating that Tai Chi is a moderate-intensity aerobic exercise in 30 min of practice. Therefore, TH-TC is medium-to-high intensity, while BW-TC is low-to-medium intensity. These findings suggest that the intensity of Tai Chi exercise depends on the type and practice time of Tai Chi.
Limitations
While this pilot study provides valuable insights, however, some limitations should be noted. First, due to the COVID-19 pandemic, the study recruited participants from only four faculties, resulting in a relatively concentrated distribution of 20 participants. Second, the sample size was small (n = 20), and all participants were male college students from a single institution in China. This limits the generalizability of the findings to other populations, such as female students or individuals of different age groups. Finally, the evaluators were conducting this type of evaluation for the first time, and despite receiving prior training, it was challenging to avoid evaluation errors.
Although this study demonstrated the short-term effects of Tai Chi on overweight college students, the short intervention period may have limited the observation of significant fitness improvements. Future studies should consider extending the intervention period to 6–12 weeks, increasing the sample size, including female participants, and expanding the recruitment institutions to improve the external validity of the research. These improvements will enable future studies to more thoroughly assess the potential long-term effects of Tai Chi on improving physical fitness and health markers, providing stronger evidence to support the field of exercise science.
Conclusions
The training programs and assessments were conducted safely without any injuries, making them appropriate for overweight Chinese male college students. Statistical analysis results demonstrated good repeatability and reliability of the measurement methods and tools used in this test. However, there were no significant changes in the mean of variables after a 2-week Tai Chi training despite the difference in exercise intensity. Further research on this project is feasible with a well-designed training program and close supervision by researchers.
Footnotes
Acknowledgments
The authors would like to acknowledge the support of all the participants and the technical experts from the National Physical Health Testing Centre of Jiaozuo Tai Chi Sports Centre for providing testing equipment services.
Authors’ Contributions
Y.N.: Conceptualization, methodology, formal analysis, writing original draft preparation, project administration, and funding acquisition. R.B.: Conceptualization, methodology, formal analysis, supervision, writing review and editing. P.K.: Methodology, formal analysis, writing review. All authors have read and agreed to the published version of the article.
Author Disclosure Statement
The authors declare no conflicts of interest.
Funding Information
This work was supported by the 2022 Key University Research Project of the Department of Education of Henan Province, China, grant number 22B890001.
Abbreviations Used
References
Supplementary Material
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