Comprehensive exercise-based cardiac rehabilitation (CR) is a Class 1A recommend therapy for patients with chronic heart failure (HF) (Pelliccia et al., 2020; McDonagh et al., 2023; Ponikowski et al., 2016). Patients with HF who engage in exercise based CR demonstrate improved quality of life, reduced hospitalization, and lower mortality rates (Molloy et al., 2024-03; Bozkurt et al., 2021). However, these CR programs are underutilized, with participation rates ranging from 10% to 30% worldwide (Beatty et al., 2023; Ozemek and Squires, 2021; Balady et al., 2011; Grace et al., 2008-10; Sanderson et al., 2003). In China, primary barriers to participation in CR have been identified and include resource scarcity and limited healthcare funding (Zhang et al., 2023; Zhang et al.). Therefore, solutions to improving CR uptake HF patients must be tailored to these barriers. In addition to overcoming the above noted barriers, resource-adapted CR programs must be sensitive to the cultural context in which they are embedded.

Commonly accepted as beneficial to one’s health, traditional Chinese exercise is a form of exercise embedded within communities throughout different regions of mainland China for nearly sixteen centuries (Wang et al., 2016; Health Qigong Management Center, 2003). Thus, this equipment-free exercise may be ideal for hospitals with limited resources (Sun, 2015), as well as patients, because it can be practiced at home, reducing barriers such as weather, transportation, and cost (Deka et al., 2017; Conraads et al., 2012). Baduanjin, translated as “eight silken movements”, is one form of traditional Chinese exercise which has been practiced for over 1,000 years. It is characterized by slow movements (physical training) synchronized with meditation (mindfulness-based training) and regulated breathing (respiratory training) to achieve a harmonious flow of energy (qi) in the body (Zou et al., 2017). Baduanjin is easy to learn, with minimal physical or cognitive demands, as it only entails eight simple movements based on traditional Chinese medicine theory. Moreover, it is an adaptable form of exercise that can be practiced in any location, at any time, without any special equipment, and requires minimal time investment (Chen et al., 2022). Hence, it is easily incorporated into daily routines and could easily be integrated into a comprehensive CR program.

Moderate intensity continuous aerobic exercise is the most widely researched type of exercise in CR and has been shown to be efficient, safe, and well-tolerated by patients with HF (Molloy et al., 2024-03). Historically, Baduanjin has been considered light-intensity exercise, regardless of the individual’s physical fitness. In contrast, our group has recently demonstrated that Baduanjin exercise falls within the moderate intensity aerobic exercise classification, based on the percent of measured oxygen consumption (VO₂), particularly for deconditioned patients such as those with HF (Chen et al., 2020). However, to date there is a lack of evidence comparing Baduanjin with conventional moderate intensity aerobic exercise such as cycle ergometer exercise, among CHF patients. This highlights a key knowledge gap for referring physicians. Therefore, the purpose of this study was to 1) compare the cardiopulmonary responses between Baduanjin and cycle ergometer exercise; and 2) compare the hemodynamic responses between Baduanjin and cycle ergometer exercise, in patients with CHF.

This is the first study to compare chronic heart failure patients’ cardiopulmonary and hemodynamic responses to Baduanjin exercise to their responses to constant-load moderate intensity cycle exercise. The intensity of both exercise modalities was calibrated according to VO₂, resulting in comparable average VO₂ for each modality. In terms of the cardiopulmonary response, Baduanjin exercise is characterized by a bimodal distribution of VO₂ responses as well as a lower respiratory burden, which is associated with greater ventilatory efficiency compared to conventional cycling. In terms of hemodynamic response, Baduanjin is demonstrated significantly lower cardiac output and elevated arterial-venous oxygen difference. These cardiopulmonary and hemodynamic responses to Baduanjin may be attributed to a higher degree of muscle engagement compared to cycle ergometer exercise.

The strength of this study lies in its comparison of the cardiopulmonary and hemodynamic differences between Baduanjin exercise and cycle exercise during matched intensity levels. Our study suggests that Baduanjin is a moderate-intensity aerobic exercise suitable for CHF patients, similar to our prior findings (Chen et al., 2020). However, there is a lack of research on real-time physiological responses comparing these two exercise modalities. When studying the cardiopulmonary and hemodynamic responses to different exercises, maintaining a consistent intensity level is crucial (Taylor et al., 2021). In a previous study, exercise intensity was matched based on heart rate response (Gary et al., 2019), while in this study, mean VO₂ during Baduanjin exercise was used for match intensity. As such, there was no significant difference in average VO₂ between the two modes of exercise. This suggests that VO₂ as a parameter is a good tool for balancing determining exercise intensity as complexities may arise when using HR due to the HR-modulating effect of pharmacotherapies commonly prescribed for CHF patients, such as β-blockers.

While average VO₂ levels were comparable between the two modes of exercise, distinct differences emerged in the intensity response curves. Cycle exercise plateaued in intensity due to a consistent power output, whereas Baduanjin exhibited an intermittent pattern with notable fluctuations, leading to a bimodal response curve. The bimodal VO₂ response observed during Baduanjin exercise is a reflection of the unique characteristics of this traditional Chinese practice, likely attributed to its structured sequence of movements with varying intensities. The presence of two VO₂ peaks corresponds to movements involving semi-squat postures, indicating that Baduanjin offers a distinctive form of moderate-intensity intermittent training. Moderate-intensity intermittent physical activity has been shown to be associated with improved executive function in older adults (MacDonald et al., 2024). Furthermore, a systematic review demonstrated that following training, moderate-intensity intermittent training results in greater reductions in fat mass, as well as improved performance on functional tests for elderly women, compared to moderate-intensity continuous training (Coswig et al., 2020/02). Therefore, Baduanjin exercise may be particularly suitable for heart failure patients with impaired executive function or functional performance, as well as for those aiming to achieve fat loss.

Baduanjin exercise imposes a lower respiratory burden by enhancing ventilatory efficiency compared to conventional cycle exercise. Similarly, a meta-analysis has also demonstrated that Baduanjin improves ventilatory efficiency (Zou et al., 2017). Patients with CHF typically exhibit an exaggerated ventilatory response for a given metabolic demand during exercise (Dubé et al., 2016-09). Our study’s findings indicate that during Baduanjin exercise, the respiratory rate is lower than that observed during cycle exercise at the same intensity, suggesting a more stable exercise-induced respiratory response during Baduanjin. This can be particularly advantageous for individuals with heart failure working to improve exercise endurance. In addition, our study show that both V_E and V_E/VCO₂ were lower during Baduanjin exercise, compared to cycle exercise. V_E quantifies the total volume of gas inhaled or exhaled per minute and is influenced by respiratory rate and tidal volume. The V_E/VCO₂ ratio indicates the proportion of ventilation relative to carbon dioxide production. The observed decrease in V_E and V_E/VCO₂ during Baduanjin exercise suggests that less ventilation is needed for the same amount of carbon dioxide production. This indicates a higher efficiency for gas exchange per breath compared to cycle exercise. Baduanjin exercise involves movements that elongate respiratory muscles, enhance thoracic compliance and mobility, reduce respiratory center stimulation, and reduce exertional dyspnea (Xie et al., 2022). Additionally, it incorporates respiratory muscle and breathing training to increase respiratory muscle strength and endurance, decrease mechanical loads such as chest wall stiffness, and facilitate deeper, slower breathing for improved gas exchange efficiency.

Baduanjin exercise imposes a lower cardiac demand with increased peripheral oxygen utilization, compared to cycling. Our results demonstrate a significantly lower CO response during Baduanjin compared with cycling. This reduction in CO, which represents the volume of blood the heart pumps per minute, suggests that Baduanjin imposes less cardiac demand than cycling. Moreover, applying the Fick principle, the C_(a-v)O₂ was significantly higher during Baduanjin exercise when compared to the cycling. The C_(a-v)O₂., which quantifies the oxygen concentration disparity between arterial and venous blood post-circulation through active muscle, indicates the efficiency with which peripheral organs, tissues, and cells extract oxygen from the mitochondria. Thus, patients engaged in Baduanjin exercise may experience improved peripheral oxygen extraction, potentially due to the engagement of multiple muscle groups characteristic of this form of exercise.

Baduanjin has been recognized for its comprehensive muscle training program which targets both the upper and lower extremities. In contrast to cycle exercise, which involves simple movements with less muscle mass engagement, Baduanjin incorporates a diverse range of movements that engage muscles throughout the body. For instance, postures such as the horse-riding stance in Postures 2, 5, and 7 can be likened to targeted quadriceps training, effectively strengthening the thigh muscles. Additionally, dynamic movements involving the forearms and fists in Postures 1, 2, 3, and 7 provide comprehensive upper extremity training, enhancing strength and coordination in the arms and hands. Furthermore, Baduanjin emphasizes high-impact and weight-bearing exercises, as illustrated in Posture 8 where practitioners push upward from their toes and land forcefully on their feet. Thus, this holistic approach to physical conditioning extends beyond the focus on lower body muscle endurance typically associated with cycle exercise. However, our current data do not allow us to distinguish perfusion changes specifically in the upper or lower extremities. The higher SVR observed during Baduanjin compared to that during cycle ergometer exercise may suggest greater muscular engagement, further evidenced by high C_(a-v)O₂. Previous research demonstrated that a single bout of resistance training elevates systemic peripheral resistance (Wakeham et al., 2025a; Wakeham et al., 2025b; Dawson et al., 1985; Miles et al., 1987). Therefore, the engagement of multiple muscle groups in Baduanjin contributes to its therapeutic benefits, particularly in expanding practitioners’ functional capacity and overall muscle strength (Esposito et al., 2011).

Our study offers novel insight into the cardiopulmonary and hemodynamic differences between Baduanjin and cycle ergometer exercise when performed at consistent intensity levels. Unlike the steady intensity of cycle exercise, Baduanjin exhibits an intermittent intensity pattern which is the result of more prominent muscle activation during various postures. Additionally, Baduanjin is associated with superior improvement in oxygen respiratory efficiency and increased peripheral oxygen utilization, which is crucial to CHF patients’ health. Furthermore, Baduanjin reduces cardiac and respiratory burden, providing a more comfortable exercise experience. From the clinical perspective, the practice’s ease-of-use and flexibility regarding time commitment and space requirements make it an attractive option for cardiac rehabilitation programs. Given these advantages, Baduanjin would be particularly effective for inclusion in cardiac rehabilitation programs for CHF patients in China, where it is widely practiced and culturally familiar.