遠距心跳變異生理回饋呼吸訓練對大學生焦慮改善的成效：隨機對照實驗

The Effectiveness of Remote Heart Rate Variability Biofeedback Breathing Training on Reducing Anxiety in College Students: A Randomized Controlled Trial

本研究旨在探討遠距心跳變異生理回饋（heart rate variability biofeedback, HRVB）是否能有效降低大學生的焦慮程度。透過智慧型手機搭配心率傳感帶，參與者能在家中進行生理回饋訓練，以增強自律神經功能並減輕主觀焦慮感受。研究對象為30名年齡介於18至22歲的大學生，隨機分派為實驗組與控制組，每組各15人。實驗組參與者使用心率傳感帶及訓練軟體，進行為期六週、每週三次、每次20分鐘的HRVB訓練；控制組則在此期間未接受任何介入。研究採用情境與特質焦慮量表（State-Trait Anxiety Inventory, STAI）與貝克焦慮量表（Beck Anxiety Inventory, BAI）測量焦慮程度，並收集心跳變異性（heart rate variability, HRV）的生理數據進行分析。研究結果顯示，實驗組在HRV的心跳間期標準偏差（standard deviation of the normal to normal intervals, SDNN）上有顯著提升，表明其自律神經功能改善；而主觀焦慮評分有降低，但未達統計顯著。本研究驗證了將呼吸頻率穩定在每分鐘6次，相等吸氣呼氣比率的遠距HRVB，能有效提升大學生心率變異性的實證，尤其是在心跳間期標準差指標上顯著提升，顯示其對自主神經功能的改善效果。研究結果為未來遠距醫療應用於焦慮介入提供了實證依據。

In daily life, cognitive neural resources are responsible for regulating physiological and emotional changes. However, anxiety not only triggers negative thinking but also overconsumes these resources, which weakens an individual’s learning ability, emotional stability, and can even progress into severe mental illnesses. According to the Ministry of Health and Welfare’s 2022 statistics, about 4% of individuals in early adulthood (ages 20–24) sought medical attention for anxiety and related symptoms, while the prevalence of anxiety symptoms among university students is as high as 24.5%, meaning one in four students is in an anxious state. Anxiety symptoms have become an increasingly serious challenge among university students. They are not only a psychological health issue that requires diagnosis and treatment, but they also deeply affect students overall well-being. These effects include threatening mental health, harming physical health, lowering academic performance, weakening interpersonal skills, and reducing quality of life. They can even cause pressure and pain for families. More severely, anxiety symptoms are significantly correlated with suicidal ideation and behavior. All types of anxiety symptoms increase the risk of suicide, emphasizing the importance of early intervention.
Heart rate variability (HRV) is a physiological indicator that measures the variation in the time intervals between heartbeats and is widely regarded as a core indicator of an individual's emotional regulation ability and adaptability to environmental changes. Anxiety disorders, including panic disorder, generalized anxiety disorder, specific phobias, and social anxiety disorder, are all associated with lower HRV. Heart rate variability biofeedback (HRVB), which synchronizes heart rate and breathing (heart rate rises during inhalation and falls during exhalation), can improve communication between the heart and the brain, enabling individuals to respond more flexibly and adaptively to situational demands. Breathing training combined with physiological feedback has been shown to effectively alleviate anxiety.
The main strategy of using physiological feedback to reduce emotional arousal is to provide participants with real-time physiological indicators and teach them emotional regulation strategies. Through immediate physiological feedback, participants can learn how to control their bodies. Therefore, physiological feedback tools must provide biological feedback to participants in real time. Although the potential of HRVB in anxiety management has been recognized, traditional methods are limited by high equipment costs and training methods restricted to medical settings, which reduce its accessibility and application efficiency. However, with technological advancements, HRVB training programs integrated with smartphones offer a solution. These programs allow individuals to train easily in daily life, significantly reduce equipment costs, and enhance the convenience and feasibility of interventions. Based on this, this study aims to develop a smartphone-based physiological feedback application and training platform to explore whether remote HRVB can effectively reduce anxiety levels in university students. By using smartphones in combination with heart rate sensors, the study will teach non-anxious university students to conduct physiological feedback training in their home environment, incorporating physiological indicators and subjective feelings to examine whether maintaining a breathing rate of six breaths per minute with equal inhalation and exhalation ratios in remote HRVB can effectively improve anxiety problems in university students.
The study uses a control group waiting for six weeks, while the experimental group will participate in six weeks of physiological feedback-assisted abdominal breathing training, with three training sessions per week, each lasting 20 minutes. Every week, participants will discuss their physiological data and effectiveness with the experimenters online. The first day of training in the first, third, and fifth weeks will be conducted in person. On the first day, researchers will demonstrate and teach the experimental group how to correctly perform abdominal breathing, use the Polar H10 heart rate sensor, and operate the smartphone application for training. Participants will be shown a breathing rate graph and taught how to adjust their breathing state using the graph, ensuring that every participant is proficient in operating it. The goal is to train participants to maintain a breathing rate of six breaths per minute with five seconds of inhalation and five seconds of exhalation. On the first day of training in the third week, the breathing rate graph will be removed, and a heart rate graph will be introduced. Participants will be taught how to effectively use the heart rate graph for training, aiming to train them to mentally count the seconds, increasing their heart rate during inhalation and decreasing it during exhalation. On the first day of the fifth week, in-person training will also be conducted, and an HRV-related indicator graph will be introduced to teach the experimental group how HRV indicators change during effective training. The goal is to train participants not only to increase their heart rate during inhalation and decrease it during exhalation but also to assess whether their breathing training method is correct.
The experimental group will use the Polar H10 heart rate sensor connected via Bluetooth to a smartphone application for training. Each training session lasts 20 minutes, beginning with a 5-minute collection of HRV-related indicators, followed by 10 minutes of abdominal breathing training, and ending with another 5-minute collection of HRV-related indicators. After each training session, participants will immediately receive feedback on their pre- and post-training HRV measurements via the smartphone application to self-assess the effectiveness of the training. After six weeks of training, all participants will complete the Chinese version of the State-Trait Anxiety Inventory, the Chinese version of the Beck Anxiety Inventory, and undergo a 5-minute physiological measurement using the physiological feedback instrument. The collected indicators will include SDNN, RMSSD, and HF.
This study employs a randomized controlled trial design, conducting six weeks of remote HRVB training, totaling 360 minutes, with a breathing frequency set at six breaths per minute. The results indicate that this training significantly improves heart rate variability in healthy university students. The contribution of this study is that it provides empirical support for the application of HRVB training in healthy populations, especially demonstrating its potential in remote medical care. The results not only show that remote HRVB training significantly improves the SDNN of university students, but the subjective anxiety indicators also show a decreasing trend. Although the total training time is shorter compared to other remote HRVB studies, using smartphone feedback to display heart rate graphs and HRV-related data, utilizing fragmented time for training, and continuously monitoring participants’conditions in the background can increase clinical convenience and more effectively promote HRV improvement. This suggests that the method has a positive effect on enhancing autonomic nervous system function. Since university students are at a critical stage of psychological and emotional development and often face academic, social, and life stressors, this non-invasive physiological feedback training that can be done at home holds potential long-term value for students’mental health. HRVB training, as a simple and effective mental health intervention strategy, reduces the location and equipment limitations of traditional anxiety interventions, requires less guidance, is affordable, and thus enhances the accessibility and practicality of interventions. It helps enhance students’self-regulation abilities and reduces health risks caused by anxiety.
However, this study only focused on healthy university students aged 18–22, with a small sample size concentrated in a single population. Therefore, the results are only applicable to individuals with similar backgrounds and cannot be generalized to other age groups or healthy adults. Future studies should consider expanding the sample size to at least 30 participants per group to improve statistical power and representativeness. Additionally, participants from different age groups and mental states (such as mild anxiety or clinical anxiety patients) should be included, and long-term follow-up studies should be conducted to examine the effectiveness of HRVB for different populations and long-term emotional regulation.
Overall, remote HRVB with a breathing frequency of six breaths per minute and an equal inhalation-exhalation ratio is a promising non-invasive anxiety intervention method. The results of this study provide empirical support for its application in remote healthcare, especially for improving university students’mental health, with potential application value.