Combined Liuzijue and mindful breathing promote greater sustained relaxation than mindful breathing alone in university students with anxiety symptoms.

Background: Mindful breathing is a well-established method for inducing relaxation, but anxious individuals often struggle to enter a mindful state. Liuzijue breathing, a traditional Chinese practice involving controlled abdominal movements, low-pitched vocalization, and guided mental focus, may facilitate mindful breathing and enhance its efficacy. This study examined whether combining Liuzijue breathing with mindful breathing could help anxious students achieve relaxation more effectively. Methods: Twenty-four male participants (aged 21 ± 2, Self-Rating Anxiety Scale score 57 ± 8) completed this randomized crossover trial with two experimental sequences on consecutive days: Sequence A: pretest, 15 min mindful breathing, posttest; Sequence B: pretest, 5 min Liuzijue breathing followed by 10 min mindful breathing, posttest. Heart rate and heart rate variability were recorded as indicators of relaxation, and subjective concentration levels during mindful breathing were assessed. In an additional session, respiration rate (RR), peripheral oxygen saturation (SpO₂), and end-tidal carbon dioxide (EtCO₂) were measured during 5 min of breathing practice and a 3 min rest period. Results: Compared with 15 min of mindful breathing alone, the combination of 5 min Liuzijue breathing followed by 10 min mindful breathing produced more sustained relaxation. Significant interaction effects were observed for heart rate, which showed a greater continued reduction, and for heart rate variability in both time and frequency domains, which showed greater progressive increases. Concentration ratings during mindful breathing were also significantly higher following Liuzijue breathing. RR was lower during Liuzijue breathing and remained significantly reduced during the first 2 min of rest. SpO₂ was significantly higher during Liuzijue breathing and at the first minute of rest. EtCO₂ was significantly lower from minutes 2-5 of Liuzijue breathing, with no differences observed during the 3 min resting period. Conclusion: The combination of Liuzijue and mindful breathing produced longer-lasting relaxation than mindful breathing alone in male university students with anxiety symptoms. The reduced RR and elevated SpO₂ induced by Liuzijue breathing may partly explain this effect. These findings suggest that Liuzijue breathing may serve as an effective preparatory technique to optimize mindfulness-based interventions.