Influence of a 30-Day Slow-Paced Breathing Intervention Compared to Social Media Use on Subjective Sleep Quality and Cardiac Vagal Activity

A holistic focus on the psychophysiology of reinvestment: A systematic review on reinvestment-related neural, cardiac vagal and oculomotor activity

BACKGROUND

Reinvestment is a psychological phenomenon during which people consciously engage in controlling their movements (i.e., movement-specific reinvestment) or decision making (i.e., decision-specific reinvestment). This can result in performance deterioration and can have detrimental consequences for individuals in various sports.

OBJECTIVES

This systematic review aimed to identify psychophysiological correlates of reinvestment to tackle the need for more objective measurements of reinvestment and to develop interventions to counteract performance-related decrements in the future. Considering brain, parasympathetic and oculomotor activity, jointly adds a holistic perspective on mechanisms underlying reinvestment.

METHODS

We conducted a systematic literature search using the PRISMA guidelines in three electronic databases (Pubmed, Web of Science and SportDiscus) on 20th of November 2024. The included studies assessed reinvestment together with psychophysiological parameters. The risk of bias of the included studies was assessed by the authors using "The Joanna Briggs Institute Critical Appraisal Checklist for Analytical Cross Sectional Studies" (Moola et al., 2020).

RESULTS

A total of N =21 studies containing a total of 795 participants were included. Of these, twelve studies considered brain activity, five considered parasympathetic cardiac activity, and two considered heart rate. Finally, two studies considered gaze behavior.

CONCLUSIONS

The findings indicate potential relationships between reinvestment and the considered psychophysiological parameters, but methods and findings appear heterogeneous in terms of task variability, population groups, and study design. To be able to draw more accurate conclusions, more systematic research programs are required to move towards a better holistic understanding of the psychophysiological correlates of reinvestment.

Heart Rate Variability Biofeedback Training Can Improve Menopausal Symptoms and Psychological Well-Being in Women with a Diagnosis of Primary Breast Cancer: A Longitudinal Randomized Controlled Trial

Breast cancer survivors experience numerous chronic symptoms linked to autonomic dysfunction including anxiety, stress, insomnia, menopausal symptoms, and cognitive impairment. Effective non-pharmacological solutions to address these are currently lacking.

METHODS

Our three-armed longitudinal randomized controlled trial assessed the effectiveness of a 4-week remote smartphone-based heart rate variability biofeedback intervention which involved daily paced breathing at 6 breaths p/min; active (12 breaths p/min) and waitlist controls were included. Heart rate variability and self-reported cancer-related symptoms were assessed at baseline, post-, and 6 months-post intervention. Participants were 60 UK-based women with primary breast cancer history (6 to 60 months post-active treatment).

RESULTS

The intervention group showed significant increases in low-frequency heart rate variability over time (F (4, 103.89) = 2.862, p = 0.027, d = 0.33), long-lasting improvement in sleep quality (F (4, 88.04) = 4.87, p = 0.001, d = 0.43) and cessations in night sweats (X2 (2, N = 59) = 6.44, p = 0.04, Cramer's V = 0.33), and reduced anxiety post-intervention compared to the active and waitlist controls (F (4, 82.51) = 2.99, p = 0.023, d = 0.44). Other findings indicated that the intervention and active control participants reported lasting improvements in cognitive function, fatigue, and stress-related symptoms (all ps < 0.05). The waitlist group reported no symptom changes across time.

CONCLUSION

Heart rate variability biofeedback is a feasible intervention for addressing diverse chronic symptoms commonly reported by breast cancer survivors.

Determining the influence of a sleep improvement intervention on medical students' sleep and fatigue: protocol of the PROMESS-Sleep clinical trial

BACKGROUND

Medical students face a demanding workload, stressful situations, and irregular sleep patterns, which can lead to elevated sleep disturbances and high fatigue levels. These difficulties may be further associated with a major decline in well-being, quality of life, performance, and health. Thus, these struggles must be addressed to reduce these students' sleep disturbances and fatigue during their curriculum.

METHODS

The PROMESS-Sleep clinical trial aims to support future healthcare professionals by enhancing their abilities to manage their sleep. The support will be provided through a three-session sleep management program. Each session will include an individual meeting between a PROMESS-Sleep expert and a medical student, during which self-care education, advice, and personalized goals will be established. The present protocol is designed to assess the influence of this program on 45 undergraduate medical students (fourth- and fifth-year) of the Lyon-Est Faculty of Medicine (Claude Bernard University Lyon 1, France). Assessments of sleep and fatigue will be conducted before and during the intervention using self-reported questionnaires and actigraphy. At the end of the third session, the student's satisfaction levels regarding the program will be assessed. The primary outcome will be changes in scores on the Pittsburgh Sleep Quality Index (PSQI) during the program. Secondary outcomes will provide a detailed characterization of changes in various aspects of sleep disturbances, fatigue, sleep habits, and sleep-wake rhythms. Exploratory outcomes will provide information regarding the students' satisfaction levels and will determine the moderators of the program's efficacy. Data will be analyzed according to the intention-to-treat principle and presented in accordance with the CONSORT Guidelines. Ethical approval has been obtained by the Institutional Review Board (IRB: 2023-07-04-03), and all procedures will be performed in adherence to the Helsinki Declaration. The results from this study will be presented at scientific conferences and in peer-reviewed scientific journals.

DISCUSSION

The results will provide valuable insights into the program's efficacy in reducing sleep disturbances and fatigue. If its efficacy is proven, PROMESS-Sleep could become an integral and sustainable part of medical education due to fostering a healthier and more resilient future for healthcare professionals. This manuscript follows the SPIRIT guidelines (Additional files 1 & 8).

TRIAL REGISTRATION

ClinicalTrials.gov: NCT06297330; retrospectively registered.

The effect of Tai Chi on elderly depression: a systematic review and meta-analysis of randomized controlled trials

Objective

This systematic review and meta-analysis assess the impact of Tai Chi on emotional well-being and quality of life in elderly individuals with depression.

Methods

Searching six databases until October 20, 2024, including Embase, PubMed, Cochrane Library, Web of Science, SinoMed, and CNKI, for randomized controlled trials (RCTs). Participants were aged ≥60 and diagnosed with depression. Tai Chi served as the main intervention in the treatment group, with the control group receiving no exercise, or only health education. The primary outcomes focused on the improvement of depressive symptoms and quality of life. Data synthesis and meta-analysis were performed using Stata 15.1 software. The protocol of this study was registered on PROSPERO (ID: CRD42023479305).

Results

Tai Chi, as the main intervention, significantly improved depressive symptoms as measured by the Geriatric Depression Scale (WMD = -5.99, 95% CI: -10.80 to -1.19, p = 0.015) compared to no exercise or health education. Subgroup analysis favored a six-month duration of Tai Chi, showing even greater benefits (WMD = -9.79, 95% CI: -13.90 to -5.69, p < 0.001). However, Tai Chi did not demonstrate a significant advantage in improving participants' scores on the Hamilton Depression Scale (WMD = -1.04, 95% CI: -3.84 to 1.76, p = 0.468).

Conclusion

Our results indicate that Tai Chi can significantly improve depressive symptoms and quality of life in elderly individuals with depression. As a daily exercise and mind-body therapy to alleviate the mood of the elderly, it is necessary to conduct more large-sample RCTs. Further research on the details of Tai Chi, such as movements, frequency, duration, and exercise periods, is essential for a dose-response relationship, contributing to the standardized promotion of Tai Chi.

The impact of screen use on sleep health across the lifespan: A National Sleep Foundation consensus statement

OBJECTIVE

To achieve consensus on whether screen-based digital media (1) in general, (2) via prebedtime content, and (3) via prebedtime light impairs sleep health in (a) childhood, (b) adolescence, and (c) adulthood. Furthermore, to address whether employing behavioral strategies and interventions may reduce the potential negative effects of screens on sleep health.

METHODS

The National Sleep Foundation convened a 16-person multidisciplinary expert panel ("Panel"). Panelists met virtually 5 times throughout 2023, during which they followed a modified Delphi RAND/UCLA Appropriateness Method to reach consensus.

RESULTS

The Panel conducted a literature review starting with 2209 articles, narrowed down to 522 relevant empirical articles and 52 relevant review articles. The search was refined to include 35 experimental/intervention studies that examined whether there was a causal link between screen-based digital media and sleep. In addition, panelists reviewed 5 recent relevant systematic review articles. After reviewing the summarized current literature, panelists voted on 10 candidate statements about whether screen use impairs sleep health. The Panel met virtually to discuss the results of the first round of votes, which was then followed by a second round of voting, ultimately achieving consensus on 5 out of the 10 statements.

CONCLUSIONS

The Panel achieved consensus that (1) in general, screen use impairs sleep health among children and adolescents, (2) the content of screen use before sleep impairs sleep health of children and adolescents, and (3) behavioral strategies and interventions may attenuate the negative effects of screen use on sleep health.

Evaluation of Autonomic Nervous System Function During Sleep by Mindful Breathing Using a Tablet Device: Randomized Controlled Trial

BACKGROUND

One issue to be considered in universities is the need for interventions to improve sleep quality and educational systems for university students. However, sleep problems remain unresolved. As a clinical practice technique, a mindfulness-based stress reduction method can help students develop mindfulness skills to cope with stress, self-healing skills, and sleep.

OBJECTIVE

We aim to verify the effectiveness of mindful breathing exercises using a tablet device.

METHODS

In total, 18 nursing students, aged 18-22 years, were randomly assigned and divided equally into mindfulness (Mi) and nonmindfulness (nMi) implementation groups using tablet devices. During the 9-day experimental period, cardiac potentials were measured on days 1, 5, and 9. In each sleep stage (sleep with sympathetic nerve dominance, shallow sleep with parasympathetic nerve dominance, and deep sleep with parasympathetic nerve dominance), low frequency (LF) value, high frequency (HF) value, and LF/HF ratios obtained from the cardiac potentials were evaluated.

RESULTS

On day 5, a significant correlation was observed between sleep duration and each sleep stage in both groups. In comparison to each experimental day, the LF and LF/HF ratios of the Mi group were significantly higher on day 1 than on days 5 and 10. LF and HF values in the nMi group were significantly higher on day 1 than on day 5.

CONCLUSIONS

The correlation between sleep duration and each sleep stage on day 5 suggested that sleep homeostasis in both groups was activated on day 5, resulting in similar changes in sleep stages. During the experimental period, the cardiac potentials in the nMi group showed a wide range of fluctuations, whereas the LF values and LF/HF ratio in the Mi group showed a decreasing trend over time. This finding suggests that implementing mindful breathing exercises using a tablet device may suppress sympathetic activity during sleep.

TRIAL REGISTRATION

UMIN-CTR Clinical Trials Registry UMIN000054639; https://tinyurl.com/mu2vdrks.

Short-Term Effects of Heart Rate Variability Biofeedback on Working Memory

Drawing upon the well-documented impact of long-term heart rate variability biofeedback (HRVB) on psychophysiological responses, this study seeks to explore the short-term effects arising from a single HRVB session during and after paced breathing exercise. The research aligns with the neurovisceral integration model, emphasizing the link between heart rate variability (HRV) levels and cognitive performance. Therefore, a randomized controlled trial employing a between-subjects design was conducted with 38 participants. Each participant was assigned to either the paced breathing intervention group or the spontaneous breathing control group. The study assessed various parameters such as cardiac vagal tone, evaluated through vagally mediated HRV measures, and working memory, measured using the N-back task. Additionally, participants' affective states were assessed through self-reported questionnaires, specifically targeting attentiveness, fatigue, and serenity. The results notably reveal enhancements in the working memory task and an elevated state of relaxation and attention following the HRVB session, as evidenced by higher averages of correct responses, serenity and attentiveness scores. However, the findings suggest that this observed improvement is not influenced by changes in cardiac vagal tone, as assessed using a simple mediation analysis. In conclusion, this study presents promising insights into the impact of a single HRVB session, laying the foundation for future research advancements in this domain.

Stress reduction experiments in daily life: Scaling from the lab to the world

Paced breathing-longer exhalation than inhalation-can show short-term improvement of physiologic responses and affective well-being, though most studies have relied on narrow sample demographics, small samples, and control conditions that fail to address expectancy effects. We addressed these limitations through an app-based experiment where participants were randomly assigned to paced breathing or sham control (hand closure) conditions. We first validated the conditions in an online sample (N = 201; Study 1) and in a lab environment (N = 72; Study 2). In the primary app-based experiment, participants (N = 3,277; Study 3) completed 3 days of baseline assessments that included three check-ins each day in which we obtained heart rate and blood pressure responses using an optic sensor and assessed current stress and emotions. Participants were then randomly assigned to either the paced breathing or hand closure condition for the next 6 days. Relative to baseline days, both conditions were associated with increased positive emotions and perceived coping, and reduced blood pressure. Moreover, the increase in positive emotions and perceived coping was not evident among a comparison sample (N = 2,600) who completed check-ins but did not participate in either of the paced breathing or sham-control conditions. However, their blood pressure declined over time, suggesting that the continual monitoring of one's blood pressure may result in detectable decreases. Our results highlight the importance of designing experiments with appropriately matched control conditions and suggest that changes associated with techniques like paced breathing, in part, may stem from positive incidental features of the technique. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Influence of Respiratory Frequency of Slow-Paced Breathing on Vagally-Mediated Heart Rate Variability

Breathing techniques, particularly slow-paced breathing (SPB), have gained popularity among athletes due to their potential to enhance performance by increasing cardiac vagal activity (CVA), which in turn can help manage stress and regulate emotions. However, it is still unclear whether the frequency of SPB affects its effectiveness in increasing CVA. Therefore, this study aimed to investigate the effects of a brief SPB intervention (i.e., 5 min) on CVA using heart rate variability (HRV) measurement as an index. A total of 75 athletes (22 female; Mage = 22.32; age range = 19-31) participated in the study, attending one lab session where they performed six breathing exercises, including SPB at different frequencies (5 cycles per minute (cpm), 5.5 cpm, 6 cpm, 6.5 cpm, 7 cpm), and a control condition of spontaneous breathing. The study found that CVA was significantly higher in all SPB conditions compared to the control condition, as indexed by both root mean square of the successive differences (RMSSD) and low-frequency HRV (LF-HRVms2). Interestingly, LF-HRVms2 was more sensitive in differentiating the respiratory frequencies than RMSSD. These results suggest that SPB at a range of 5 cpm to 7 cpm can be an effective method to increase CVA and potentially improve stress management and emotion regulation in athletes. This short SPB exercise can be a simple yet useful tool for athletes to use during competitive scenarios and short breaks in competitions. Overall, these findings highlight the potential benefits of incorporating SPB into athletes' training and competition routines.

Psychophysiological Effects of Slow-Paced Breathing on Adolescent Swimmers' Subjective Performance, Recovery States, and Control Perception

This study examined the effect of a Slow-Paced Breath (i.e., 6 breaths per minute) without Biofeedback (SPB-NoHRVB) protocol on semi-elite adolescent swimmers' psychological and physiological states during a seven-week ecological training period. A linear mixed-effects multilevel regression analysis approach was used with 13 adolescent national-level swimmers. Athletes were randomly assigned to an intervention group (n = 7) and a control group (n = 6). Seven waves of assessments were completed weekly during a seven-week training preparation in ecological conditions. During the protocol, swimmers completed subjective quantitative measures (RESTQ-36-R-Sport; cognitive perceived stress and control states about the training process, training subjective performance, and subjective internal training load) and physiological heart rate (HR) (HR of exercise, absolute and normalized HR recovery during the first 60 s of recovery; HRR60 and nHRR60) and heart rate variability (HRV) (MeanRR, RMSSD, LFnu and HFnu, LF/HF ration) tests (through a submaximal heart rate (5'-5' test) once a week. Results revealed that the SPB-NoHRVB protocol significantly predicts biopsychosocial recovery states, cognitive perception of control, and training subjective performance (i.e., a significant effect of the SPB-NoHRVB protocol with the dependent variables simple time trajectories). However, no significant effects were found for biopsychosocial stress scales, cognitively perceived stress, HR, or HRV markers. Our results suggest that SPB-NoHRVB induces simple evolutions over time for crucial variables in athletes' adaptation to the training process (i.e., cognitive appraisals and biopsychosocial states). In contrast, it highlights that SPB-NoHRVB does not induce better stress states. This specific effect on the resource component is an exciting result that will be discussed in the manuscript.

[Development of intelligent monitoring system based on Internet of Things and wearable technology and exploration of its clinical application mode]

Wearable monitoring, which has the advantages of continuous monitoring for a long time with low physiological and psychological load, represents a future development direction of monitoring technology. Based on wearable physiological monitoring technology, combined with Internet of Things (IoT) and artificial intelligence technology, this paper has developed an intelligent monitoring system, including wearable hardware, ward Internet of Things platform, continuous physiological data analysis algorithm and software. We explored the clinical value of continuous physiological data using this system through a lot of clinical practices. And four value points were given, namely, real-time monitoring, disease assessment, prediction and early warning, and rehabilitation training. Depending on the real clinical environment, we explored the mode of applying wearable technology in general ward monitoring, cardiopulmonary rehabilitation, and integrated monitoring inside and outside the hospital. The research results show that this monitoring system can be effectively used for monitoring of patients in hospital, evaluation and training of patients' cardiopulmonary function, and management of patients outside hospital.

Effect of coherent breathing on mental health and wellbeing: a randomised placebo-controlled trial

Breathwork may offer simple tools for stress resilience. We conducted the largest parallel randomised-controlled trial on breathwork to date (NCT05676658) wherein 400 participants on the research platform Prolific were randomised, in blocks of 2 via remote software, to coherent breathing at ~ 5.5 breaths/min or a matched attention-placebo at 12 breaths/min, for ~ 10 min/day over 4 weeks. Participants were blinded to their allocated interventions, both of which were paced with equal inhalation:exhalation ratios. There were no differences on credibility and expectancy of benefit between conditions. At the primary timepoint post-intervention for the primary outcome subjective stress, there was no significant group by time interaction (F(1,377) = 0.089, p = 0.765, ηp2 < 0.001) nor main effect of group (F = 0.002, p = 0.961, ηp2 < 0.001), however there was a significant main effect of time (F = 72.1, p < 0.001, ηp2 = 0.161). Similar results were found at 1-month follow-up for stress and for secondary outcomes of anxiety, depression and wellbeing. There were overall improvements on these mental health and wellbeing outcomes from baseline to post-intervention and follow-up across both groups, yet the magnitude of this improvement was not different between arms. Accordingly, we found no measurable effect of coherent breathing over and above a well-designed breathwork placebo at improving mental health and wellbeing. Methodological considerations and recommendations for robust future research are discussed. Funder: Sasakawa Young Leaders Fellowship Fund, Tokyo, Japan.

Validity and Efficacy of the Elite HRV Smartphone Application during Slow-Paced Breathing

Slow-paced breathing is a clinical intervention used to increase heart rate variability (HRV). The practice is made more accessible via cost-free smartphone applications like Elite HRV. We investigated whether Elite HRV can accurately measure and augment HRV via its slow-paced breathing feature. Twenty young adults completed one counterbalanced cross-over protocol involving 10 min each of supine spontaneous (SPONT) and paced (PACED; 6 breaths·min-1) breathing while RR intervals were simultaneously recorded via a Polar H10 paired with Elite HRV and reference electrocardiography (ECG). Individual differences in HRV between devices were predominately skewed, reflecting a tendency for Elite HRV to underestimate ECG-derived values. Skewness was typically driven by a limited number of outliers as median bias values were ≤1.3 ms and relative agreement was ≥very large for time-domain parameters. Despite no significant bias and ≥large relative agreement for frequency-domain parameters, limits of agreement (LOAs) were excessively wide and tended to be wider during PACED for all HRV parameters. PACED significantly increased low-frequency power (LF) for Elite HRV and ECG, and between-condition differences showed very large relative agreement. Elite HRV-guided slow-paced breathing effectively increased LF values, but it demonstrated greater precision during SPONT and in computing time-domain HRV.

The impact of a guided paced breathing audiovisual intervention on anxiety symptoms in Palestinian children: a pilot randomized controlled trial

BACKGROUND

Children in Palestine may be at high risk for anxiety symptoms. However, access to mental health services is limited. Therefore, the objective of this study was to conduct a pilot randomized controlled trial to examine whether a guided audiovisual paced breathing intervention was feasible, acceptable, and improved anxiety symptoms in Palestinian children.

METHODS

Students (6-10 years old) in an after-school program in Palestine were randomly assigned to the intervention or control condition. All participants completed a pre- and post-intervention measure of anxiety using the Revised Children's Manifest Anxiety Scale. Participants in the intervention completed 24 sessions over 8 weeks and rated breathing ease as well as pre- and post-session relaxation on a 5-point Likert scale. To examine condition differences in post-intervention anxiety, four analyses of covariance were conducted, adjusting for age, sex, and pre-intervention anxiety.

RESULTS

A total of 144 participants (65.3% girls; Mage  = 7.5 ± 1.2; 50% per condition) enrolled in the study. There were no differences in demographics or baseline anxiety between the two conditions (ps > .05). Participants reported that it was easy to breathe during the sessions (Ms = 4.1-4.7, SDs = 0.5-1.1). For all but the first session, participants reported being more relaxed after the breathing session than before (ps < .003). Post-intervention, participants in the intervention reported fewer anxiety symptoms compared to participants in the control condition (ps < .01).

CONCLUSION

A guided paced breathing audiovisual intervention was feasible and had a significant positive impact on anxiety symptoms in Palestinian children compared to a control condition. Future research should examine whether the audiovisual guided breathing intervention significantly improves long-term outcomes.

Closed-Loop Auditory Stimulation to Guide Respiration: Preliminary Study to Evaluate the Effect on Time Spent in Sleep Initiation during a Nap

Various stimulation systems to modulate sleep structure and function have been introduced. However, studies on the time spent in sleep initiation (TSSI) are limited. This study proposes a closed-loop auditory stimulation (CLAS) to gradually modulate respiratory rhythm linked to the autonomic nervous system (ANS) activity directly associated with sleep. CLAS is continuously updated to reflect the individual's current respiratory frequency and pattern. Six participants took naps on different days with and without CLAS. The average values of the TSSI are 14.00 ± 4.24 and 9.67 ± 5.31 min in the control and stimulation experiments (p < 0.03), respectively. Further, the values of respiratory instability and heart rate variability differ significantly between the control and stimulation experiments. Based on our findings, CLAS supports the individuals to gradually modulate their respiratory rhythms to have similar characteristics observed near sleep initiation, and the changed respiratory rhythms influence ANS activities, possibly influencing sleep initiation. Our approach aims to modulate the respiratory rhythm, which can be controlled intentionally. Therefore, this method can probably be used for sleep initiation and daytime applications.

Transcutaneous Vagus Nerve Stimulation for Insomnia in People Living in Places or Cities with High Altitudes: A Randomized Controlled Trial

BACKGROUND

The purpose of this study was to investigate the effectiveness and safety of transcutaneous vagus nerve stimulation (tVNS) to improve insomnia in the special environment of a plateau.

METHODS

This study was a single-center, single-blind, randomized controlled trial. A total of 100 patients with insomnia at high altitude were randomized into three groups receiving either transcutaneous vagus nerve stimulation intervention in the left ear tragus (treatment group), pseudo-stimulation intervention (sham group), or cognitive behavioral therapy for insomnia (CBTI group). The primary measure was the Pittsburgh Sleep Quality Index (PSQI) score. In addition, we assessed the patients' objective sleep status with polysomnography and evaluated changes in the Insomnia Severity Index Scale (ISI) and Generalized Anxiety Disorder-7 (GAD-7) scores. We used one-way ANOVA and repeated-measures ANOVA for analysis.

RESULTS

Patients' PSQI, ISI, and GAD-7 scale scores significantly decreased after 4 weeks of tVNS treatment and were greater than those of the control group. Polysomnographic data also demonstrated shortened sleep latency and longer deep sleep in the patients.

CONCLUSION

tVNS is effective in improving sleep quality and reducing anxiety levels in high-altitude insomnia patients but should be confirmed in future adequate and prolonged trials to guide clinical promotion.

Effects of Covid-19 on the autonomic nervous system in elite athletes assessed by heart rate variability

Introduction

Covid-19 is a viral airway and systemic infection which can negatively affect the function of the autonomic nervous system. Cardiovascular autonomic function is essential for peak athletic performance. The aim of this study was to assess the effects of a Covid-19 disease on the autonomic nervous system of German elite athletes using heart rate variability (HRV).

Methods

60 elite athletes (aged 22.88 ± 4.71 years) were recruited, 30 of whom had undergone a Covid-19 disease. Heart rate (HR), blood pressure (BP) and heart rate variability (HRV) were measured during rest and during an orthostatic challenge.

Results

At rest and after orthostatic stress blood pressure and the root mean square of successive differences (RMSDD) were significantly lower in Covid-19 athletes (COV) than in control athletes (CON) (p = 0.002 and p = 0.004, respectively); heart rate was significantly higher (p = 0.001). COV showed a significantly greater reduction in blood pressure and elevation of heart rate than CON, but the change in RMSSD did not differ significantly during the orthostatic challenge.

Conclusion

These results show a change in cardiac parasympathetic activity and cardiovascular autonomic function in German elite athletes after Covid-19. These findings further the understanding of effects of the Covid-19 disease on the cardiovascular physiology in athletes. Heart rate variability may be a helpful tool in the return-to-play assessment of elite athletes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11332-023-01067-7.

Acute and Long-Lasting Effects of Slow-Paced Breathing on Handball Team Coach's Match Stress

Stress was previously defined as a response to any demand for change. These demands are noticeable during sport events, not only in athletes but also in coaches. Therefore, this study aimed to determine the influence of slow-paced breathing (SPB) on acute stress to handball coaches during official matches. One professional handball coach, aged 37 (height, 180 cm; weight, 80 kg), took part in the study. His salivary cortisol (C) concentration and alpha-amylase (AA) activity were measured, and his heart rate (HR) was monitored during six official matches. In the first three matches the SPB training protocol was not followed. From match four to match six, the coach performed SPB training every day and directly before the match. The decrease observed in AA was statistically significant with a large effect size (1.80). The trend of change in HR is visible and similar for matches with and without SPB. However, for SPB matches, there is a lower starting point compared to matches without SPB (89.81 ± 6.26 and 96.62 ± 8.10, respectively). Moreover, values of AA on SPB matches were smaller before the match (93.92 ± 15.89) compared to the same time point in non-SPB matches (115.30 ± 26.00). For AA, there is a significant effect size in the half-time (2.00) and after the match (-2.14). SPB matches showed a lower increase in AA. SPB might be used as one of the possible tools that could help coaches in achieving a desirable mental state during the match.

The Effects of Breathing Exercises on Patients Having Laparoscopic Cholecystectomy Surgery

The aim of the study is to determine the effect of breathing exercises on patients who underwent laparoscopic cholecystectomy in terms of their level of anxiety, sleep, and recovery of quality after surgery. A randomized, controlled experimental research model was used in this work. This study was conducted in surgery clinic of a university hospital between December 2020 and May 2021. The research was completed with 58 patients in the experimental group and 57 patients in the control group. The mean Visual Analog Sleep Scale and state anxiety score of the patients in the control group was higher in the morning of the operation and on the 1st, 15th, and 30th days after the operation than that of the experimental group patients, and the difference was statistically significant (p < .05). The correlations between recovery quality, state anxiety, and sleep quality on the first postoperative day were significant at (p < .05) in the opposite direction.

Conscious connected breathing with breath retention intervention in adults with chronic low back pain: protocol for a randomized controlled pilot study

BACKGROUND

Chronic pain is a major source of human suffering, and chronic low back pain (cLBP) is among the most prevalent, costly, and disabling of pain conditions. Due to the significant personal and societal burden and the complex and recurring nature of cLBP, self-management approaches that can be practiced at home are highly relevant to develop and test. The respiratory system is one of the most integrated systems of the body, and breathing is bidirectionally related with stress, emotion, and pain. Thus, the widespread physiological and psychological impact of breathing practices and breathwork interventions hold substantial promise as possible self-management strategies for chronic pain. The primary aim of the current randomized pilot study is to test the feasibility and acceptability of a conscious connected breathing with breath retention intervention compared to a sham control condition.

METHODS

The rationale and procedures for testing a 5-day conscious connected breathing with breath retention intervention, compared to a deep breathing sham control intervention, in 24 adults (18-65 years) with cLBP is described. Both interventions will be delivered using standardized audio recordings and practiced over 5 days (two times in-person and three times at-home), and both are described as Breathing and Attention Training to reduce possible expectancy and placebo effects common in pain research. The primary outcomes for this study are feasibility and acceptability. Feasibility will be evaluated by determining rates of participant recruitment, adherence, retention, and study assessment completion, and acceptability will be evaluated by assessing participants' satisfaction and helpfulness of the intervention. We will also measure other clinical pain, psychological, behavioral, and physiological variables that are planned to be included in a follow-up randomized controlled trial.

DISCUSSION

This will be the first study to examine the effects of a conscious connected breathing with breath retention intervention for individuals with chronic pain. The successful completion of this smaller-scale pilot study will provide data regarding the feasibility and acceptability to conduct a subsequent trial testing the efficacy of this breathing self-management practice for adults with cLBP.

TRIAL REGISTRATION

Clinicaltrials.gov, identifier NCT04740710 . Registered on 5 February 2021.

Deep breathing exercise at work: Potential applications and impact

Hypertension is a major contributor to cardiovascular disease and daily deep breathing exercise (DBE) is a promising intervention to reduce blood pressure and stress in adults. DBE is simple, time-efficient, and does not require specialized equipment, allowing participation in a wide variety of settings. The workplace is an ideal setting to implement DBE at the national level for several reasons, including a large proportion of waking hours spent in the workplace, high levels of sedentary time at work, prevalence of work-related stress, and regular breaks throughout the day potentially reducing worker error. While the degree of adherence to daily workplace DBE will be the responsibility of the individual, employers and managers can (and should) do much to remove barriers to participation. Specifically, this could include: implementing regular short breaks or classes to perform DBE throughout the day, covering subscription costs for smartphone applications that guide DBE, and creating incentive programs for continuing DBE participation. Implementing DBE in the workplace is a pragmatic approach to provide a low-cost blood pressure and stress reduction therapy to a substantial portion of the adult population in the US, at least 50% of whom have high blood pressure.

Konzeption einer App mit der Technik des „Entschleunigten Atmens“ zur Selbstregulation für Jugendliche während der Corona-Pandemie

Zusammenfassung. Theoretischer Hintergrund: Belastungen und Stress nahmen bei den Jugendlichen während der COVID-19-Pandemie zu. Das Entschleunigte Atmen (EA) wirkt kurz- wie langfristig stressreduzierend und stabilisierend. Mithilfe einer App, die diese Technik vermittelt, haben Schüler_innen auch während des pandemiebedingten Distanz-Lernens die Möglichkeit, an einem schulbasierten Training teilzunehmen. Fragestellung: Wie hoch ist die Erreichbarkeit und wie werden inhaltliche und nicht-inhaltliche Aspekte der App bewertet? Methode: Eine mehrmodulige App, die das EA erklärt, zum Anwenden und Üben dieser Technik anleitet, wurde konzipiert und entwickelt. Während eines Pilotprojekts in der zweiten Welle der COVID-19-Pandemie wurde das vierwöchige Training von 6. bis 8. Klässler_innen erprobt. Das gesamte Training bewerteten 31 Schüler_innen, das EA sieben. Ergebnisse: Erste Ergebnisse deuten auf eine zufriedenstellende nicht-inhaltliche und eine gute inhaltliche Akzeptanz hin. Die Erreichbarkeit hingegen war gering. Alle Ergebnisse werden deskriptiv vorgestellt. Diskussion und Schlussfolgerung: Die App-Revision soll Präsenzmodule beinhalten, die motivationalen Anreize erhöhen und an einer größeren Stichprobe durchgeführt werden.

Effects of voluntary slow breathing on heart rate and heart rate variability: A systematic review and a meta-analysis

Voluntary slow breathing (VSB) is used as a prevention technique to support physical and mental health, given it is suggested to influence the parasympathetic nervous system (PNS). However, to date, no comprehensive quantitative review exists to support or refute this claim. We address this through a systematic review and meta-analysis of the effects of VSB on heart rate variability (HRV). Specifically, we focus on HRV parameters indexing PNS activity regulating cardiac functioning, referred to as vagally-mediated (vm)HRV: (1) during the breathing session (i.e., DURING), (2) immediately after one training session (i.e., IM-AFTER1), as well as (3) after a multi-session intervention (i.e., AFTER-INT). From the 1842 selected abstracts, 223 studies were suitable for inclusion (172 DURING, 16 IM-AFTER1, and 49 AFTER-INT). Results indicate increases in vmHRV with VSB, DURING, IM-AFTER1, and AFTER-INT. Given the involvement of the PNS in a large range of health-related outcomes and conditions, VSB exercises could be advised as a low-tech and low-cost technique to use in prevention and adjunct treatment purposes, with few adverse effects expected.

Unexpected Cardiovascular Oscillations at 0.1 Hz During Slow Speech Guided Breathing (OM Chanting) at 0.05 Hz

Slow breathing at 0.1 Hz (i.e., 6 cycles per minute, cpm) leads to strong cardiovascular oscillations. However, the impact of breathing below 6 cpm is rarely addressed. We investigated the influence of OM chanting, an ancient Indian mantra, with approx. 3 respiratory cpm (0.05 Hz) on the synchronisation of heart period (RR), respiration (RESP) and systolic blood pressure (SBP). Nine healthy, trained speech practitioners chanted three sequences of five subsequent OM with 2 min pauses in between. Each single OM chanting consisted of taking a deep breath and a long “OM” during expiration and lasted approx. 20 s. ECG, respiration and blood pressure were recorded continuously, of which the RR tachogram, RESP and SBP were derived. Synchronisation between the signals was computed using the phase difference between two signals. During OM chanting synchronisation among the oscillations of RR, SBP and RESP was significantly increased compared to rest. Furthermore, OM chanting at breathing frequencies between 0.046 and 0.057 Hz resulted in 0.1 Hz oscillations in RR and SBP. In conclusion, OM chanting strongly synchronized cardiorespiratory and blood pressure oscillations. Unexpected oscillations at 0.1 Hz in SBP and RR appear at breathing frequencies of approx. 0.05 Hz. Such frequency doubling may originate from an interaction of breathing frequency with endogenous Mayer waves.

Effect of slow, deep breathing on visceral pain perception and its underlying psychophysiological mechanisms

BACKGROUND

Studies using somatic pain models have shown the hypoalgesic effects of slow, deep breathing. We evaluated the effect of slow, deep breathing on visceral pain and explored putative mediating mechanisms including autonomic and emotional responses.

METHODS

Fifty-seven healthy volunteers (36 females, mean age = 22.0 years) performed controlled, deep breathing at a slow frequency (6 breaths per minute), controlled breathing at a normal frequency (14 breaths per minute; active control), and uncontrolled breathing (no-treatment control) in randomized order. Moderate painful stimuli were given during each condition by delivering electrical stimulation in the distal esophagus. Participants rated pain intensity after each stimulation. Heart rate variability and self-reported arousal were measured during each condition.

KEY RESULTS

Compared to uncontrolled breathing, pain intensity was lower during slow, deep breathing (Cohen's d = 0.40) and normal controlled breathing (d = 0.47), but not different between slow, deep breathing and normal controlled breathing. Arousal was lower (d = 0.53, 0.55) and heart rate variability was higher (d = 0.70, 0.86) during slow, deep breathing compared to the two control conditions. The effect of slow, deep breathing on pain was not mediated by alterations in heart rate variability or arousal but was moderated by pain catastrophizing.

CONCLUSIONS AND INFERENCES

Slow, deep breathing can reduce visceral pain intensity. However, the effect is not specific to the slow breathing frequency and is not mediated by autonomic or emotional responses, suggesting other underlying mechanisms (notably distraction). Whether a long-term practice of slow, deep breathing can influence (clinical) visceral pain warrants to be investigated.

A pilot study investigating the relationship between heart rate variability and blood pressure in young adults at risk for cardiovascular disease

Background

Cardiovascular disease is one of the leading causes of death globally with hypertension being a primary cause of premature death from this disease process. Individuals with a family history of cardiovascular disease and hypertension are at a greater risk for developing the same sequela. Autonomic cardiac control is important in the level of cardiac function. One intervention that is effective in improving cardiovascular function is heart rate variability biofeedback training. The purpose of our study was to determine the effectiveness of heart rate biofeedback training on HRV and blood pressure in individuals with a family history of cardiovascular disease.

Methods

Thirty-four participants (76.5% female, 22.7 ± 4.3 years) completed a baseline assessment and training using an established short-term HRV protocol followed by two weeks of at-home paced breathing employing a smartphone application. The participants were then reassessed in a biofeedback clinic.

Results

The participants physiological measures showed a significant increase in means between pre and post intervention of SDNN (t (32) = 2.177, p =.037) and TP, (t (32) = 2.327 p = .026). Correlation noted a medium effect on diastolic blood pressure and high frequency heart rate variability, F, r = .41, n =33, p < .05. A multiple regression with all predictor variables in the model found no significance with diastolic and systolic blood pressure.

Conclusions

The findings from this pilot study demonstrated that a two-week paced breathing intervention may assist in reducing heart rate and diastolic blood pressure while improving heart rate variability.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40885-021-00185-z.

Self-Regulation in High-Level Ice Hockey Players: An Application of the MuSt Theory

The purpose of the study was to examine the validity of core action elements and feeling states in ice hockey players in the prediction of performance. A second aim of the study was to explore the effectiveness of a 30-day program targeting action and emotion regulation. Participants were male ice hockey players drawn from two teams competing at the highest level of the junior Finnish ice hockey league. They were assigned to a self-regulation (n = 24) and a control (n = 19) group. The self-regulation program focused on the recreation of optimal execution of core action elements and functional feeling states. Separate repeated measures MANOVAs indicated significant differences in ratings of perceived control and execution accuracy ratings of self-selected visual and behavioral components of the action (critical for optimal performance) and psychobiosocial (feeling) states across recalled best and worst games. Results support the use of both action- and emotion-centered strategies for performance enhancement. Future research including psychophysiological markers is warranted.

Can news with positive or negative content affect and a relaxation pause improve the emotional state of health care professionals? A randomized online experiment during COVID-19 pandemic

A cause of mental distress during the COVID-19 pandemic is media exposure, which can impact health care professionals (HCPs) who must keep up to date with the statistics and procedures to fight the outbreak. This study aimed to evaluate the effects of listening to negative and positive news about COVID-19 pandemic and a relaxation pause audio. For that, we measured the emotional state through Likert items in a scale developed to assess how anxious, stressed, hopeful, conscious about emotions, irritated, despondent, joyful, optimistic, and preoccupied, he or she was feeling in the moment of evaluation. In an online experiment, an HCPs sample of 245 participants were randomly assigned to either listen to negative or positive news contents about COVID-19. After that, both groups were guided by a relaxation pause activity in which they paid attention to the body and breath. They were assessed before and after listening to each audio. After listening to negative news, participants entered in a more negative emotional state than at baseline (p < 0.001) and compared with participants who listened to positive news (p < 0.001). Both groups improved their emotional state after performing the proposed brief relaxation (p < 0.001). These results show the importance of HCPs being aware and controlling the content of consumed news. A brief relaxation practice can mitigate the negative effects of consuming information with negative content.

COVID-19 news valence effects on emotion and its modulation by a relaxation: A randomized online experiment during COVID-19 pandemic

This study evaluated how news with positive and negative content about COVID-19, as well as a relaxation pause, affect the emotional state. We also investigated the association between emotional state and practicing meditation/yoga, physical activity or having a mental disease. For that, a sample of 717 participants, recruited through social media, were randomly assigned to listen to negative or positive news about COVID-19. After that, both groups were guided through a short relaxation pause. Their emotional state was measured before they listened to the audios and after each audio. Mixed linear models were used to evaluate the effects of news group, relaxation pause, mental health and well-being practices. Negative news worsened their emotional state, whereas positive news improved it. A brief relaxation pause improved the effects of negative news content and may mitigate the effects of this valence of information. Practicing physical activity, meditation/yoga was associated with better emotional responses.

Single Slow-Paced Breathing Session at Six Cycles per Minute: Investigation of Dose-Response Relationship on Cardiac Vagal Activity

The practice of slow-paced breathing (SPB) has been linked to a range of positive outcomes, such as decreasing symptoms of depression, anxiety, and stress, as well as increasing well-being. Among the suggested mechanisms of action, SPB has been shown to increase cardiac vagal activity (CVA). The present study aimed to investigate whether there is a dose-response relationship modulating the effects of SPB on CVA. A total of 59 participants were involved in this study. In a within-subject design, participants attended the lab five times, and realized SPB at six cycles per minute with different durations (5, 10, 15, and 20 min), as well as a control condition without SPB. CVA was indexed via the root mean square of successive differences (RMSSD). During SPB, findings showed an increase in RMSSD in all conditions compared to the control condition. However, no differences were found in RMSSD among the different session durations, during SPB or during the resting measurement completed immediately after SPB. Noteworthily, session duration showed an influence on the spontaneous respiratory frequency in the resting measurement occurring immediately after SPB. Specifically, respiratory frequency appears to decrease with session duration, thus potentially contributing to additional relaxing effects.

Psychophysiological effects of slow-paced breathing at six cycles per minute with or without heart rate variability biofeedback

Heart rate variability (HRV) biofeedback, referring to slow-paced breathing (SPB) realized while visualizing a heart rate, HRV, and/or respiratory signal, has become an adjunct treatment for a large range of psychologic and medical conditions. However, the underlying mechanisms explaining the effectiveness of HRV biofeedback still need to be uncovered. This study aimed to disentangle the specific effects of HRV biofeedback from the effects of SPB realized alone. In total, 112 participants took part in the study. The parameters assessed were emotional (valence, arousal, and control) and perceived stress intensity as self-report variables and the root mean square of the successive differences (RMSSD) as a physiologic variable. A main effect of condition was found for emotional valence only, valence being more positive overall in the SPB-HRVB condition. A main effect of time was observed for all dependent variables. However, no main effects for the condition or time x condition interaction effects were observed. Results showed that for PRE and POST comparisons (referring, respectively, to before and after SPB), both SPB-HRVB and SPB-NoHRVB conditions resulted in a more negative emotional valence, lower emotional arousal, higher emotional control, and higher RMSSD. Future research might investigate psychophysiological differences between SPB-HRVB and SPB-NoHRVB across different time periods (e.g., long-term interventions), and in response to diverse psychophysiological stressors.

Slow-Paced Breathing: Influence of Inhalation/Exhalation Ratio and of Respiratory Pauses on Cardiac Vagal Activity

Slow-paced breathing has been shown to enhance the self-regulation abilities of athletes via its influence on cardiac vagal activity. However, the role of certain respiratory parameters (i.e., inhalation/exhalation ratio and presence of a respiratory pause between respiratory phases) still needs to be clarified. The aim of this experiment was to investigate the influence of these respiratory parameters on the effects of slow-paced breathing on cardiac vagal activity. A total of 64 athletes (27 female; Mage = 22, age range = 18–30 years old) participated in a within-subject experimental design. Participants performed six breathing conditions within one session, with a 5 min washout period between each condition. Each condition lasted 5 min, with 30 respiratory cycles, and each respiratory cycle lasted 10 s (six cycles per minute), with inhalation/exhalation ratios of 0.8, 1.0, 1.2; and with or without respiratory pauses (0.4 s) between respiratory phases. Results indicated that the root mean square of successive differences (RMSSD), a marker of cardiac vagal activity, was higher when exhalation was longer than inhalation. The presence of a brief (0.4 s) post-inhalation and post-exhalation respiratory pause did not further influence RMSSD. Athletes practicing slow-paced breathing are recommended to use an inhalation/exhalation ratio in which the exhalation phase is longer than the inhalation phase.

Reciprocal Relationships between Sleep Problems and Problematic Smartphone Use in Taiwan: Cross-Lagged Panel Study

Prior studies have suggested a link between sleep problems and problematic smartphone use. However, the causal relationships between these two variables have not been identified, particularly in adolescence. Utilizing longitudinal panel data from Taiwan, this report examined the temporal relationships between sleep problems and problematic smartphone use among adolescents. One thousand and thirty-nine students (Grades 7-12) were surveyed at two-time points with a 6-month interval. The results of cross-lagged panel analysis showed that sleep problems at Time 1 significantly predicted problematic smartphone use at Time 2. Problematic smartphone use at Time 1 also significantly predicted sleep problems at Time 2. These findings applied to boys and girls and suggested that temporal relationships between sleep problems and problematic smartphone use among teenagers are reciprocal. Accordingly, increasing sleep quality may prevent future problematic smartphone use, while reducing problematic smartphone use may prevent sleep problems in adolescents.

Transcutaneous Auricular Vagus Nerve Stimulation Combined With Slow Breathing: Speculations on Potential Applications and Technical Considerations

OBJECTIVES

Transcutaneous auricular vagus nerve stimulation (taVNS) is a relatively novel noninvasive neurostimulation method that is believed to mimic the effects of invasive cervical VNS. It has recently been suggested that the effectiveness of taVNS can be enhanced by combining it with controlled slow breathing. Slow breathing modulates the activity of the vagus nerve and is used in behavioral medicine to decrease psychophysiological arousal. Based on studies that examine the effects of taVNS and slow breathing separately, this article speculates on some of the conditions in which this combination treatment may prove effective. Furthermore, based on findings from studies on the optimization of taVNS and slow breathing, this article provides guidance on how to combine taVNS with slow breathing.

MATERIALS AND METHODS

A nonsystematic review.

RESULTS

Both taVNS and slow breathing are considered promising add-on therapeutic approaches for anxiety and depressive disorders, chronic pain, cardiovascular diseases, and insomnia. Therefore, taVNS combined with slow breathing may produce additive or even synergistic beneficial effects in these conditions. Studies on respiratory-gated taVNS during spontaneous breathing suggest that taVNS should be delivered during expiration. Therefore, this article proposes to use taVNS as a breathing pacer to indicate when and for how long to exhale during slow breathing exercises.

CONCLUSIONS

Combining taVNS with slow breathing seems to be a promising hybrid neurostimulation and behavioral intervention.

Emotional Intelligence Training: Influence of a Brief Slow-Paced Breathing Exercise on Psychophysiological Variables Linked to Emotion Regulation

Designing emotional intelligence training programs requires first testing the effectiveness of techniques targeting its main dimensions. The aim of this study was to investigate the effects of a brief slow-paced breathing (SPB) exercise on psychophysiological variables linked to emotion regulation, namely cardiac vagal activity (CVA), as well as perceived stress intensity, emotional arousal, and emotional valence. A total of 61 participants completed a 5-min SPB exercise and a control condition of a 5-min rest measurement. CVA was indexed with the root mean square of successive differences (RMSSD). Participants were also asked to rate their perceived stress intensity, emotional arousal, and emotional valence. Results showed that CVA was higher during SPB in comparison to the control condition. Contrary to our hypothesis, perceived stress intensity and emotional arousal increased after SPB, and perceived emotional valence was less positive after SPB. This could be explained by experiencing dyspnea (i.e., breathing discomfort), and the need to get acclimatized to SPB. Consequently, we may conclude that although physiological benefits of SPB on CVA are immediate, training may be required in order to perceive psychological benefits.

Symptom Management Among Cancer Survivors: Randomized Pilot Intervention Trial of Heart Rate Variability Biofeedback

Chronic cancer-related symptoms (stress, fatigue, pain, depression, insomnia) may be linked with sympathetic nervous system over-activation and autonomic imbalance. Decreased heart rate variability (HRV) is an indicator of autonomic dysregulation that is commonly observed among cancer survivors. HRV biofeedback (HRVB) training induces HRV coherence, which maximizes HRV and facilitates autonomic and cardiorespiratory homeostasis. This randomized, wait-list-controlled, pilot intervention trial tested the hypothesis that HRVB can improve HRV coherence and alleviate cancer-related symptoms. The intervention group (n = 17) received 4-6 weekly HRVB training sessions until participants demonstrated skill acquisition. Controls (n = 17) received usual care. Outcomes assessed at baseline and follow-up included 15-min HRV recordings (HRV Coherence Ratio), and symptoms of: stress, distress, post-traumatic stress disorder (PTSD), pain, depression, fatigue, and sleep disturbance. Linear mixed models for repeated measures were used to assess Group-by-Time interactions, pre- versus post-treatment differences in mean symptom scores, and group differences at follow-up. Mean HRV Coherence Ratios (± standard error) improved in the HRVB group at follow-up (baseline: 0.37 ± 0.05, post-intervention: 0.84 ± 0.18, p = 0.01), indicating intervention validity. Statistically significant Group-by-Time interactions indicated treatment-related improvements in HRV Coherence Ratios (p = 0.03, Pre-vs. post-treatment effect size [Cohen's d]: 0.98), sleep symptoms (p = 0.001, d = 1.19), and sleep-related daytime impairment (p = 0.005, d = 0.86). Relative to controls, the intervention group experienced trends toward improvements in stress, distress, fatigue, PTSD, and depression, although no other statistically significant Group-by-Time interactions were observed. This pilot intervention found that HRVB training reduced symptoms of sleep disturbance among cancer survivors. Larger-scale interventions are warranted to further evaluate the role of HRVB for managing symptoms in this population. Registration: NCT03692624 www.clinicaltrials.gov.

Using Slow-Paced Breathing to Foster Endurance, Well-Being, and Sleep Quality in Athletes During the COVID-19 Pandemic

The coronavirus disease 2019 (COVID-19) has been causing major disruptions in the sporting world. Negative physiological and psychological effects on athletes have been reported, such as respiratory issues and increased stress. Therefore, it is timely to support this population by presenting cost-effective and accessible intervention techniques to reduce this impact. Slow-paced breathing (SPB) has the potential to counteract many of the detrimental effects of COVID-19 that can directly affect sports performance. In this article, we present and justify the use of SPB in athletes by focusing on three key outcomes, namely aerobic endurance performance, emotional well-being, and sleep quality. We examine the physiological mechanisms that underpin these three outcomes and review literature showing that SPB can activate anti-inflammatory pathways, increase lung capacity and, in turn, improve aerobic endurance, emotional well-being, and sleep quality. We conclude that interventions using SPB can have preventive and rehabilitative properties for athletes. Future studies should empirically test the potential of SPB to help this specific population.

The Influence of Slow-Paced Breathing on Executive Function

Abstract. The aim of this experiment was to test the immediate effects of slow-paced breathing on executive function. Slow-paced breathing is suggested to increase cardiac vagal activity, and the neurovisceral integration model predicts that higher cardiac vagal activity leads to better executive functioning. In total, 78 participants (41 men, 37 women; Mage = 23.22 years) took part in two counterbalanced experimental conditions: a 3 × 5 min slow-paced breathing condition and a television viewing control condition. After each condition, heart rate variability was measured and participants performed three executive function tasks: the color-word match Stroop (inhibition), the automated operation span task (working memory), and the modified card sorting task (cognitive flexibility). Results showed that performance on executive function tasks was better after slow-paced breathing compared to control, with higher scores observed for Stroop interference accuracy, automated operation span score, and perseverative errors, but not Stroop interference reaction times. This difference in executive function between experimental conditions was not mediated by cardiac vagal activity. Therefore, findings only partially align with predictions of the neurovisceral integration model. Slow-paced breathing appears a promising technique to improve immediate executive function performance. Further studies are recommended that address possible alternative underlying mechanisms and long-term effects.

Brain Functional Mechanisms Determining the Efficacy of Transcutaneous Auricular Vagus Nerve Stimulation in Primary Insomnia

Transcutaneous auricular vagus nerve stimulation (taVNS) has been reported to be effective in the treatment of primary insomnia (PI); however, its efficacy varies considerably across individuals for reasons that are unclear. In order to clarify the underlying mechanisms, this study investigated the effects of taVNS on spontaneous neuronal activity and autonomic nervous system function by functional magnetic resonance imaging (fMRI) and measurement of heart rate variability (HRV), respectively, in patients with PI. Forty patients with PI were divided into effective (group A) and ineffective (group B) groups based on their response to taVNS as determined by Pittsburgh Sleep Quality Index score reduction rate (group A ≥ 25% and group B < 25%). Spontaneous neuronal activity was measured by fractional amplitude of low-frequency fluctuations (fALFF) and HRV values and was compared between the two groups as well as before vs after taVNS. We then analyzed the correlations among efficacy of taVNS for 4 weeks, the fALFF and HRV values during continuous taVNS state. The results showed that the HRV parameter values (i.e., root mean square of successive differences, percentage of adjacent NN intervals differing by >50 ms, and high frequency) of group A were higher than those of group B during continuous taVNS state. In the fMRI scan, the fALFF values of the right cerebellum, right medial superior frontal gyrus, and bilateral supplementary motor area—which belong to the sensorimotor network (SMN)—were lower in group A than in group B during continuous taVNS state. The correlation analysis revealed that the efficacy of continuous taVNS and HRV and fALFF values were interrelated. These findings demonstrate that differential regulation of the SMN by the autonomic nervous system may be responsible for inter-individual variations in the efficacy of taVNS and suggest that HRV and fALFF are potential biomarkers for predicting PI patients’ response to taVNS treatment.

The Effects of Presleep Slow Breathing and Music Listening on Polysomnographic Sleep Measures - a pilot trial

Knowledge on efficient ways to reduce presleep arousal and, therefore, improve sleep, is scanty. We explored the effects of presleep slow breathing and music listening conditions on sleep quality and EEG power spectral density in young adults in a randomized, controlled trial with a crossover design. Participants’ (N = 20, 50% females) sleep was measured on two consecutive nights with polysomnography (40 nights), the other night serving as the control condition. The intervention condition was either a 30-minute slow breathing exercise or music listening (music by Max Richter: Sleep). The intervention and control conditions were placed in a random order. We measured heart rate variability prior to, during and after the intervention condition, and found that both interventions increased immediate heart rate variability. Music listening resulted in decreased N2 sleep, increased frontal beta1 power spectral density, and a trend towards increased N3 sleep was detected. In the slow breathing condition higher central delta power during N3 was observed. While some indices pointed to improved sleep quality in both intervention groups, neither condition had robust effects on sleep quality. These explorative findings warrant further replication in different populations.

Influence of Slow-Paced Breathing on Inhibition After Physical Exertion

This research aims to investigate whether slow-paced breathing (SPB) improves adaptation to psychological stress, and specifically inhibition, when it is performed before or after physical exertion (PE). According to the resonance model, SPB is expected to increase cardiac vagal activity (CVA). Further, according to the neurovisceral integration model, CVA is positively linked to executive cognitive performance, and would thus play a role in the adaptation to psychological stress. We hypothesized that SPB, in comparison to a control condition, will induce a better adaptation to psychological stress, measured via better inhibitory performance. Two within-subject experiments were conducted with athletes: in the first experiment (N = 60) SPB (or control – neutral TV documentary) was realized before PE (“relax before PE”), and in the second experiment (N = 60) SPB (or the watching TV control) was realized after PE (“relax after PE”). PE consisted of 5 min Burpees, a physical exercise involving the whole body. In both experiments the adaptation to psychological stress was investigated with a Stroop task, a measure of inhibition, which followed PE. Perceived stress increased during PE (partial η² = 0.63) and during the Stroop task (partial η² = 0.08), and decreased during relaxation (partial η² = 0.15), however, no effect of condition was found. At the physiological level PE significantly increased HR, RF, and decreased CVA [operationalized in this research via the root mean square of successive differences (RMSSD)] in both experiments. Further, the number of errors in the incongruent category (Stroop interference accuracy) was found to be lower in the SPB condition in comparison to the control condition, however, these results were not mediated by RMSSD. Additionally, the Stroop interference [reaction times (RTs)] was found to be lower overall in “relax before PE,” however, no effect was found regarding SPB and Stroop interference (RTs). Overall, our results suggest that SPB realized before or after PE has a positive effect regarding adaptation to psychological stress and specifically inhibition, however, the underlying mechanisms require further investigation.

Training of paced breathing at 0.1 Hz improves CO2 homeostasis and relaxation during a paced breathing task

Volitional control of breathing often leads to excessive ventilation (hyperventilation) among untrained individuals, which disrupts CO2 homeostasis and may elicit a set of undesirable symptoms. The present study investigated whether seven days of training without any anti-hyperventilation instructions improves CO2 homeostasis during paced breathing at a frequency of 0.1 Hz (6 breaths/minute). Furthermore, the present study investigated the effects of training on breathing-related changes in affective state to examine the hypothesis that training improves the influence of slow paced breathing on affect. A total of 16 participants performed ten minutes of paced breathing every day for seven days. Partial pressure of end-tidal CO2 (PetCO2), symptoms of hyperventilation, affective state (before and after breathing), and pleasantness of the task were measured on the first, fourth, and seventh days of training. Results showed that the drop in PetCO2 significantly decreased with training and none of the participants experienced a drop in PetCO2 below 30 mmHg by day seven of training (except one participant who already had PetCO2 below 30 mmHg during baseline), in comparison to 37.5% of participants on the first day. Paced breathing produced hyperventilation symptoms of mild intensity which did not decrease with training. This suggests that some participants still experienced a drop of PetCO2 that was deep enough to produce noticeable symptoms. Affective state was shifted towards calmness and relaxation during the second and third laboratory measurements, but not during the first measurement. Additionally, the breathing task was perceived as more pleasant during subsequent laboratory measurements. The obtained results showed that training paced breathing at 0.1 Hz led to decrease in hyperventilation. Furthermore, the present study suggests that training paced breathing is necessary to make the task more pleasant and relaxing.