The Association Between Preoperative Inspiratory Muscle Training Variables and Postoperative Pulmonary Complications in Subjects With Esophageal Cancer.

BACKGROUND: Preoperative inspiratory muscle training (IMT) is frequently used in patients waiting for major surgery to improve respiratory muscle function and to reduce the risk of postoperative pulmonary complications (PPCs). Currently, the mechanism of action of IMT in reducing PPCs is still unclear. Therefore, we investigated the associations between preoperative IMT variables and the occurrence of PPCs in patients with esophageal cancer. METHODS: A multi-center cohort study was conducted in subjects scheduled for esophagectomy, who followed IMT as part of a prehabilitation program. IMT variables included maximum inspiratory pressure (PImax) before and after IMT and IMT intensity variables including training load, frequency, and duration. Associations between PImax and IMT intensity variables and PPCs were analyzed using independent samples t tests and logistic regression analyses, corrected for age and pulmonary comorbidities and stratified for the occurrence of anastomotic leakages. RESULTS: Eighty-seven subjects were included (69 males; mean age 66.7 ± 7.3 y). A higher PImax (odds ratio 1.016, P = .07) or increase in PImax during IMT (odds ratio 1.020, P = .066) was not associated with a reduced risk of PPCs after esophagectomy. Intensity variables of IMT were also not associated (P ranging from .16 to .95) with PPCs after esophagectomy. Analyses stratified for the occurrence of anastomotic leakages showed no associations between IMT variables and PPCs. CONCLUSIONS: This study shows that an improvement in preoperative inspiratory muscle strength during IMT and training intensity of IMT were not associated with a reduced risk on PPCs after esophagectomy. Further research is needed to investigate other possible factors explaining the mechanism of action of preoperative IMT in patients undergoing major surgery, such as the awareness of patients related to respiratory muscle function and a diaphragmatic breathing pattern.

Phrenic Nerve Stimulation for Acute Respiratory Failure.

Diaphragm inactivity during invasive mechanical ventilation leads to diaphragm atrophy and weakness, hemodynamic instability, and ventilatory heterogeneity. Absent respiratory drive and effort can, therefore, worsen injury to both lung and diaphragm and is a major cause of failure to wean. Phrenic nerve stimulation (PNS) can maintain controlled levels of diaphragm activity independent of intrinsic drive and as such may offer a promising approach to achieving lung and diaphragm protective ventilatory targets. Whereas PNS has an established role in the management of chronic respiratory failure, there is emerging interest in how its multisystem putative benefits may be temporarily harnessed in the management of invasively ventilated patients with acute respiratory failure.

Determination of the minimal important difference for inspiratory muscle strength in people with severe and very severe COPD.

OBJECTIVE: Inspiratory muscle training is recommended for people with chronic obstructive pulmonary disease (COPD) with inspiratory muscle weakness. Clinical interpretation of changes in inspiratory muscle strength could be helped by the determination of cut-off values. The aim of this study was to estimate the minimal important difference for inspiratory muscle strength assessed with maximal inspiratory pressure (MIP) in people with COPD. DESIGN: Post hoc analysis of a randomized controlled trial (EMI2 study) including people with severe to very severe COPD undergoing a pulmonary rehabilitation program was conducted. The determination of the minimal important difference was realized using both anchor-based and distribution-based methods. SETTING: The study includes patients admitted to the rehabilitation program unit of the Centre Hospitalier des Pays de Morlaix (Morlaix, France) between March 5, 2014 and September 8, 2016. PARTICIPANTS: Seventy-three people with severe to very severe COPD (age 62.2 ± 8.0 years, forced expiratory volume in 1 s 36.4 ± 9.5% of theoretical) were analyzed. INTERVENTION: Patients followed a standardized pulmonary rehabilitation program 5 days a week for 4 weeks. The program included aerobic training, ground-based outdoor walking training, and strengthening of lower and upper limb muscles. MAIN MEASURES: At the end of the pulmonary rehabilitation program, MIP improved by 14.8 ± 14.9 cmH2O (p < 0.05). Regarding the anchor-based method, only the modified Medical Research Council was selected as an appropriate anchor. The receiver operating characteristic curve analysis reported a minimal important difference of 13.5 cmH2O (sensibility: 75% specificity: 67.5%). Using distribution-based methods, the estimate of minimal important difference was 7.9 cmH2O (standard error of measurement method) and 10.9 cmH2O (size effect method). RESULTS: The estimations proposed by this study ranged from 7.9 to 13.5 cmH2O. CONCLUSIONS: The measurement of minimal important difference is a simple tool for assessing the changes of inspiratory muscle strength during a pulmonary rehabilitation program. We propose a minimal important difference of 13.5 cmH2O for the improvement of MIP. Further studies are needed to confirm this estimation.ClinicalTrials.gov identifier: NCT02074813.

Short-Term L-Citrulline Supplementation Does Not Affect Inspiratory Muscle Oxygenation and Respiratory Performance in Older Adults.

In sports nutrition, nitric oxide (NO•) precursors such as L-citrulline are widely used to enhance NO• bioavailability, which is considered an ergogenic aid. Our study aimed to examine the effect of short-term L-citrulline supplementation on respiratory muscles' performance, fatigue, and oxygenation in older adults. Fourteen healthy older males took 6 g of L-citrulline or a placebo for seven days in a double-blind crossover design. Pulmonary function via spirometry (i.e., forced expired volume in 1 s (FEV1), forced vital capacity (FVC), and their ratio)), fractional exhaled nitric oxide (NO•), maximal inspiratory pressure (MIP), rate of perceived exertion, and sternocleidomastoid muscle oxygenation (i.e., oxyhemoglobin (Δ[O2Hb]) and de-oxyhemoglobin (Δ[HHb]), total hemoglobin concentration (Δ[tHb]), and tissue saturation index (TSI%)) were evaluated at baseline, after seven days of L-citrulline supplementation, and after incremental resistive breathing to task failure of the respiratory muscles. The exhaled NO• value was only significantly increased after the supplementation (26% p < 0.001) in the L-citrulline condition. Pulmonary function, MIP, rate of perceived exertion, and sternocleidomastoid muscle oxygenation were not affected by the L-citrulline supplementation. In the present study, although short-term L-citrulline supplementation increased exhaled NO•, no ergogenic aids were found on the examined parameters at rest and after resistive breathing to task failure in older adults.

Inspiratory-Expiratory Muscle Training Improved Respiratory Muscle Strength in Dialysis Patients: A Pilot Randomised Trial.

End-stage kidney disease (ESKD) exposes patients to progressive physical deconditioning involving the respiratory muscles. The aim of this pilot randomized controlled trial was to determine the feasibility and effectiveness of low-intensity respiratory muscle training (RMT) learned at the hospital and performed at home. A group of ESKD patients (n = 22) were randomized into RMT or usual care (control group, CON) in a 1:1 ratio. The respiratory training was performed at home with an inspiratory-expiratory system for a total of 5 min of breathing exercises in a precise rhythm (8 breaths per minute) interspersed with 1 min of rest, two times per day on nondialysis days for a total of 4 weeks, with the air resistance progressively increasing. Outcome measures were carried out every 4 weeks for 3 consecutive months, with the training executed from the 5th to the 8th week. Primary outcomes were maximal inspiratory and expiratory pressure (MIP, MEP), while secondary outcomes were lung capacity (FEV1, FVC, MVV). Nineteen patients without baseline between-group differences completed the trial (T: n = 10; Age: 63 ± 10; Males: n = 12). Both MIP and MEP significantly improved at the end of training in the T group only, with a significant difference of MEP of 23 cmH2O in favor of the RMT group (p = 0.008). No significant variations were obtained for FVC, FEV1 or MVV in either group, but there was a greater decreasing trend over time for the CON group, particularly for FVC (t = -2.00; p = 0.046). Low-fatiguing home-based RMT, with a simple device involving both inspiratory and expiratory muscles, may significantly increase respiratory muscle strength.

The effect of inspiratory muscle training and detraining on the respiratory metaboreflex.

NEW FINDINGS: What is the central question of this study? Is the attenuation of the respiratory muscle metaboreflex preserved after detraining? What is the main finding and its importance? Inspiratory muscle training increased respiratory muscle strength and attenuated the respiratory muscle metaboreflex as evident by lower heart rate and blood pressure. After 5 weeks of no inspiratory muscle training (detraining), respiratory muscle strength was still elevated and the metaboreflex was still attenuated. The benefits of inspiratory muscle training persist after cessation of training, and attenuation of the respiratory metaboreflex follows changes in respiratory muscle strength. ABSTRACT: Respiratory muscle training (RMT) improves respiratory muscle (RM) strength and attenuates the RM metaboreflex. However, the time course of muscle function loss after the absence of training or 'detraining' is less known and some evidence suggest the respiratory muscles atrophy faster than other muscles. We sought to determine the RM metaboreflex in response to 5 weeks of RMT and 5 weeks of detraining. An experimental group (2F, 6M; 26 ± 4years) completed 5 weeks of RMT and tibialis anterior (TA) training (each 5 days/week at 50% of maximal inspiratory pressure (MIP) and 50% maximal isometric force, respectively) followed by 5 weeks of no training (detraining) while a control group (1F, 7M; 24 ± 1years) underwent no intervention. Prior to training (PRE), post-training (POST) and post-detraining (DETR), all participants underwent a loaded breathing task (LBT) to failure (60% MIP) while heart rate and mean arterial blood pressure (MAP) were measured. Five weeks of training increased RM (18 ± 9%, P < 0.001) and TA (+34 ± 19%, P < 0.001) strength and both remained elevated after 5 weeks of detraining (MIP-POST vs. MIP-DETR: 154 ± 31 vs. 153 ± 28 cmH2O, respectively, P = 0.853; TA-POST vs. TA-DETR: 86 ± 19 vs. 85 ± 16 N, respectively, P = 0.982). However, the rise in MAP during LBT was attenuated POST (-11 ± 17%, P = 0.003) and DETR (-9 ± 9%, P = 0.007) during the iso-time LBT. The control group had no change in MIP (P = 0.33), TA strength (P = 0.385), or iso-time MAP (P = 0.867) during LBT across all time points. In conclusion, RM and TA have similar temporal strength gains and the attenuation of the respiratory muscle metaboreflex remains after 5 weeks of detraining.

Respiratory dysfunction in patients with chronic neck pain: systematic review and meta-analysis.

PURPOSE: To determine the differences in respiratory muscle strength and pulmonary function between patients with chronic neck pain (CNP) and asymptomatic individuals. METHODS: Databases were MEDLINE, CINAHL, Scopus, Web of Science and EMBASE up to the end of September 2021. Studies with cross-sectional and longitudinal design were selected, with adult patients with CNP and asymptomatic individuals with reports respiratory function. RESULTS: 11 studies met the inclusion criteria and 10 were included in the meta-analysis showing a statistically significant reduction in inspiratory/expiratory muscle strength (MIP/MEP) in the patients with CNP compared with the asymptomatic individuals (mean difference (MD) for MIP, -11.67 [-14.57 to -8.77]; MD for MEP, -11.80 [-14.99 to -8.60]) and pulmonary function: vital capacity (standardized mean difference (SMD), -0.31 [-0.56 to -0.06]); maximum voluntary ventilation (SMD, -0.36 [-0.59 to -0.14]); forced vital capacity (SMD, -0.53 [-0.99 to -0.06]); peak expiratory flow (SMD, -0.58 [-1.03 to -0.12]); and forced expiratory volume in the first second (SMD, -0.28 [-0.51 to -0.05]). CONCLUSIONS: Patients with CNP have reduced respiratory muscle strength and pulmonary function compared with asymptomatic individuals, and this difference could be clinically meaningful. However, more studies of high methodological quality and longitudinal studies are needed to strengthen the results of this meta-analysis. IMPLICATIONS FOR REHABILITATIONRespiratory dysfunction has been observed in patients with chronic neck pain.Patients with chronic neck pain present a decrease in respiratory muscle strength and pulmonary function compared with asymptomatic individuals.Respiratory pattern disorders should be considered in the clinical context of chronic neck pain.Interventions focused on respiratory muscle training could be helpful for this population.

Inspiratory muscle training in addition to conventional physical rehabilitation in hospitalized patients undergoing hematopoietic stem cell transplantation: a randomized controlled trial.

PURPOSE: To investigate the effect of inspiratory muscle training (IMT) in addition to conventional physical rehabilitation on muscle strength, functional capacity, mobility, hemodynamics, fatigue, and quality of life in hospitalized patients undergoing hematopoietic stem cell transplantation (HSCT). METHODS: We conducted a randomized controlled trial in 57 inpatients with hematological diseases undergoing HSCT. Conventional inpatient physical rehabilitation was delivered to the IMT (n = 27) and control (CON; n = 30) groups according to usual care, and the first group additionally performed IMT. The IMT was prescribed according to clinical and laboratory parameters at 40% of maximal inspiratory pressure (MIP), 5 days/week throughout the hospitalization, in sessions of 10-20 min. The primary outcome was MIP and the secondary outcomes were maximal expiratory pressure (MEP), peripheral muscle strength (handgrip and sit-to-stand tests), functional capacity (6-min step test), mobility (timed up and go test), blood pressure, quality of life (EORTC-QLQ-C30), and fatigue (FACT-F) at admission and hospital discharge. RESULTS: The population was predominately autologous HSCT. The IMT group significantly increased the MIP (P < 0.01) and decreased both fatigue (P = 0.01) and blood pressure (P < 0.01) compared with control. No differences were found between admission and hospital discharge in peripheral and expiratory muscle strength, functional capacity, mobility, and quality of life in both groups (P > 0.05). CONCLUSIONS: Our results support the effectiveness of IMT as part of rehabilitation for HSCT inpatients, improving inspiratory muscle strength, and reducing fatigue and blood pressure. TRIAL REGISTRATION: NCT03373526 (clinicaltrials.gov).

Effects of a new respiratory muscle training device in community-dwelling elderly men: an open-label, randomized, non-inferiority trial.

BACKGROUND: Respiratory muscle training (RMT) has various clinical benefits in older adults; however, the low adherence to training remains a challenging issue. The present study aimed to confirm the efficacy of a new device that combines inspiratory muscle training and a positive expiratory pressure (IMT/PEP) compared to that of a Threshold IMT device (Philips Respironics Inc), and to determine whether home-based training differed from rehabilitation center training. METHODS: This four-arm, multicenter, parallel, non-inferiority trial randomized 80 active community-dwelling older men (mean age = 72.93 ± 5.02 years) to center-based groups (new IMT/PEP device or Threshold IMT device; 16 supervised sessions) or home-based groups (new IMT/PEP device or Threshold IMT device; 2 supervised sessions and individual sessions). Participants in all groups performed RMT twice a day for 8 weeks. Assessments were performed at baseline and post-training. The primary outcomes were maximum inspiratory pressure and maximal expiratory pressure. The secondary outcomes included forced vital capacity and forced expiratory volume in the first second, peak cough flow, diaphragm thickness, VO2 peak, the International Physical Activity Questionnaire score, electromyographic activities of the sternocleidomastoid muscle, and skeletal muscle mass and phase angle as measured by bioimpedance analysis. In addition, rates of adherence to each protocol were also compared. RESULTS: Among all groups, the maximal inspiratory pressure was improved post-training, while the maximal expiratory pressure showed improvement only in the IMT/PEP groups. The overall non-inferiority of the IMT/PEP device was thus validated. A statistically significant improvement in diaphragm thickness was found. However, no consistent improvement was shown in other secondary outcomes. No significant difference in training adherence rate between protocols was observed (mean adherence rate of 91-99%). CONCLUSION: Compared to the Threshold IMT, the new IMT/PEP device did not result in a significant difference in maximal inspiratory pressure but did improve maximal expiratory pressure in older men. The IMT/PEP device's improved usability, which is associated with exercise adherence, provided distinct advantages in this cohort. If proper education is first provided, home-based RMT alone may provide sufficient effects in older individuals. TRIAL REGISTRATION: This trial was registered in the database cris.nih.go.kr (registration number KCT0003901 ) on 10/05/2019.

Effects of Cough Training and Inspiratory Muscle Training on Cough Strength in Older Adults: A Randomized Controlled Trial.

PURPOSE: While the need for preventive strategies to reduce the incidence of aspiration pneumonia has been indicated, it is also important to investigate effective training methods to improve cough function, which is associated with the development of aspiration pneumonia. This study aimed to investigate whether a 4-week home-based unsupervised cough training (CT) or inspiratory muscle training (IMT) program was effective in improving cough strength in older adults. METHODS: Fifty-three ambulatory older adults without airflow limitations were randomly assigned to one of three groups: a CT group (n = 18), an IMT group (n = 18), or a control group (n = 17). The CT and IMT groups performed home-based unsupervised training with a device for 4 weeks. Cough strength (cough peak flow), forced vital capacity, and respiratory muscle strength were assessed at the 4-week and 16-week follow-up. Intention-to-treat analyses were performed to investigate differences between the three groups using linear mixed models. RESULTS: At the 4-week follow-up, the CT group showed significant increases in cough peak flow and forced vital capacity compared with the control group, while the IMT group showed significant increases in inspiratory muscle strength compared with the cough training and control groups. At the 16-week follow-up, the CT group showed a significant increase in cough peak flow compared with the IMT group. CONCLUSION: These preliminary results suggest that a 4-week home-based CT program may have short-term effectiveness in improving cough peak flow in ambulatory older adults. TRIAL REGISTRATION: This trial was registered on UMIN-CTR on 01/05/2018 (UMIN000031656).

Randomised controlled trial to investigate the use of high-frequency airway oscillations as training to improve dyspnoea (TIDe) in COPD.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterised by symptomatic dyspnoea and reduced exercise tolerance, in part as a result muscle weakness, for which inspiratory muscle training (IMT) may be useful. Excess mucus hypersecretion commonly coexists in COPD and may lead to reduce ventilation, further impacting on breathlessness. Devices for sputum clearance may be employed to aid mucus expectoration. This trial aimed to explore the effectiveness of a combined IMT and high-frequency airway oscillating (HFAO) device in the management of dyspnoea. METHODS: This was a double-blinded, randomised sham-controlled trial which recruited symptomatic patients with COPD. Patients were randomised to either a HFAO device (Aerosure) or sham device for 8 weeks, three times a day. The primary outcome was the Chronic Respiratory Questionnaire dyspnoea (CRQ-D) domain. Pre-specified subgroup analyses were performed including those with respiratory muscle weakness, excessive sputum and frequent exacerbators. RESULTS: 104 participants (68% men, mean (SD) age 69.75 years (7.41), forced expiratory volume in 1 s per cent predicted 48.22% (18.75)) were recruited to this study with 96 participants completing. No difference in CRQ-D was seen between groups (0·28, 95% CI -0.19 to 0.75, p=0.24), though meaningful improvements were seen over time in both groups (mean (SD) HFAO 0.45 (0.78), p<0.01; sham 0.73 (1.09), p<0.01). Maximal inspiratory pressure significantly improved in the HFAO group over sham (5.26, 95% CI 0.34 to 10.19, p=0.05). Similar patterns were seen in the subgroup analysis. CONCLUSION: There were no statistical differences between the HFAO and the sham group in improving dyspnoea measured by the CRQ-D. TRIAL REGISTRATION NUMBER: ISRCTN45695543.

Respiratory muscle training improves exercise tolerance and respiratory muscle function/structure post-stroke at short term: A systematic review and meta-analysis.

BACKGROUND: Previous reviews relating to the effects of respiratory muscle training (RMT) after stroke tend to focus on only one type of training (inspiratory or expiratory muscles) and most based the results on poor-quality studies (PEDro score ≤4). OBJECTIVES: With this systematic review and meta-analysis, we aimed to determine the effects of RMT (inspiratory or expiratory muscle training, or mixed) on exercise tolerance, respiratory muscle function and pulmonary function and also the effects depending on the type of training performed at short- and medium-term in post-stroke. METHODS: Databases searched were MEDLINE, PEDro, CINAHL, EMBASE and Web of Science up to the end of April 2020. The quality and risk of bias for each included study was examined by the PEDro scale (including only high-quality studies) and Cochrane Risk of Bias tool. RESULTS: Nine studies (463 patients) were included. The meta-analysis showed a significant increase in exercise tolerance [4 studies; n = 111; standardized mean difference [SMD] = 0.65 (95% confidence interval 0.27-1.04)]; inspiratory muscle strength [9 studies; n = 344; SMD = 0.65 (0.17-1.13)]; inspiratory muscle endurance [3 studies; n = 81; SMD = 1.19 (0.71-1.66)]; diaphragm thickness [3 studies; n = 79; SMD = 0.9 (0.43-1.37)]; and peak expiratory flow [3 studies; n = 84; SMD = 0.55 (0.03-1.08)] in the short-term. There were no benefits on expiratory muscle strength and pulmonary function variables (forced expiratory volume in 1 s) in the short-term. CONCLUSIONS: The meta-analysis provided moderate-quality evidence that RMT improves exercise tolerance, diaphragm thickness and pulmonary function (i.e., peak expiratory flow) and low-quality evidence for the effects on inspiratory muscle strength and endurance in stroke survivors in the short-term. None of these effects are retained in the medium-term. Combined inspiratory and expiratory muscle training seems to promote greater respiratory changes than inspiratory muscle training alone.

Respiratory muscle weakness and its association with exercise capacity in patients with chronic obstructive pulmonary disease.

INTRODUCTION: Although COPD patients commonly present respiratory complaints despite pharmacological treatment, dyspnea does not correlate directly and linearly with spirometric data, a fact that makes it difficult to select patients for pulmonary rehabilitation. Thus, seems logical that the measurement of respiratory muscle strength could help in this initial assessment if it presents a good correlation with exercise capacity. The aim of this study is to assess whether patients with muscle weakness, characterized as a reduction in maximal inspiratory pressure (PImax) below 70% of predicted value, have a good relationship between the assessed respiratory muscle strength and the exercise capacity measured by the 6-min walk test (6MWT) in patients with COPD. METHODS: Patients diagnosed with COPD according to the 2019 Global Initiative for Chronic Obstructive Lung Disease (GOLD) on regular use of their medications, without exacerbations for 3 months or more and with respiratory muscle weakness (PImax < 70% of predicted) performed 6MWT in a 30-m-long flat corridor. RESULTS: Data from 81 patients were analyzed. There was a strong correlation between the distance of the 6MWD with the PImax (r = 0.764, p < 0.0001). When separating the sample by the 350-m cut in the 6MWD, we found that the patients with the worst performance in the test are those who present the greatest respiratory muscle weakness. CONCLUSION: PImax correlates well with exercise capacity, and patients with respiratory muscle weakness could be referred to a pulmonary rehabilitation protocol tied to inspiratory muscle training.

Effect of inspiratory muscle training associated or not to physical rehabilitation in preoperative anatomic pulmonary resection: a systematic review and meta-analysis.

OBJECTIVE: The aim of this study is to systematically review the effect of inspiratory muscle training (IMT) associated or not with physical rehabilitation in the preoperative period of anatomical pulmonary resection. METHODS: Search in the databases: MEDLINE, Cochrane CENTRAL, EMBASE, LILACS and PEDro up to November 2019. Randomized clinical trials (RCTs) were included in adults in the preoperative period of pulmonary resection. The selection of studies and data extraction was performed by two independent reviewers. The risk of bias assessed with RoB 2.0 and the quality of evidence with GRADE. PROSPERO: CRD42018105859. RESULTS: Six RCTs were included; patients who underwent IMT in the preoperative period showed a significant improvement in functional capacity assessed by the 6-min walk test (6WT) (MD 28,93 [IC 95% 0,28; 57,58], p = 0,04, I2 = 0%) and significantly reduced the length of hospital stay (MD -3,63 [IC 95% -4,96; -2,29], p = 0,00, I2 = 0%). There was no significant difference between groups regarding pulmonary function, in postoperative complications such as pneumonia (RR 0,56 [IC 95% 0,29; 1,10], p = 0,09, I2 = 0%), atelectasis (RR 0,81 [IC 95% 0,24; 2,69], p = 0,72, I2 = 0%), mechanical ventilation > 48 h (RR 0,43 [IC 95% 0,12; 1,58], p = 0,20, I2 = 0%), in mortality (RR 0,33 [IC 95% 0,04; 3,12], p = 0,33, I2 = 0%), and quality of life. CONCLUSION: IMT associated with physical exercise in the preoperative period of pulmonary resection improves functional capacity and reduces the length of hospital stay in the postoperative period.

The physiology of singing and implications for 'Singing for Lung Health' as a therapy for individuals with chronic obstructive pulmonary disease.

Singing is an increasingly popular activity for people with chronic obstructive pulmonary disease (COPD). Research to date suggests that 'Singing for Lung Health' may improve various health measures, including health-related quality-of-life. Singing and breathing are closely linked processes affecting one another. In this narrative review, we explore the physiological rationale for 'Singing for Lung Health' as an intervention, focusing on the abnormalities of pulmonary mechanics seen in COPD and how these might be impacted by singing. The potential beneficial physiological mechanisms outlined here require further in-depth evaluation.

Acute L-Citrulline Supplementation Increases Nitric Oxide Bioavailability but Not Inspiratory Muscle Oxygenation and Respiratory Performance.

The present study aimed to investigate whether acute L-citrulline supplementation would affect inspiratory muscle oxygenation and respiratory performance. Twelve healthy males received 6 g of L-citrulline or placebo in a double-blind crossover design. Pulmonary function (i.e., forced expired volume in 1 s, forced vital capacity and their ratio), maximal inspiratory pressure (MIP), fractional exhaled nitric oxide (NO•), and sternocleidomastoid muscle oxygenation were measured at baseline, one hour post supplementation, and after an incremental resistive breathing protocol to task failure of the respiratory muscles. The resistive breathing task consisted of 30 inspirations at 70% and 80% of MIP followed by continuous inspirations at 90% of MIP until task failure. Sternocleidomastoid muscle oxygenation was assessed using near-infrared spectroscopy. One-hour post-L-citrulline supplementation, exhaled NO• was significantly increased (19.2%; p < 0.05), and this increase was preserved until the end of the resistive breathing (16.4%; p < 0.05). In contrast, no difference was observed in the placebo condition. Pulmonary function and MIP were not affected by the L-citrulline supplementation. During resistive breathing, sternocleidomastoid muscle oxygenation was significantly reduced, with no difference noted between the two supplementation conditions. In conclusion, a single ingestion of 6 g L-citrulline increased NO• bioavailability but not the respiratory performance and inspiratory muscle oxygenation.

Functionally relevant threshold of inspiratory muscle strength in patients with chronic obstructive pulmonary disease.

OBJECTIVES: We aimed to identify the inspiratory muscle strength thresholds below which exercise capacity is compromised in men with chronic obstructive pulmonary disease (COPD). METHODS: We measured the maximum static inspiratory mouth pressure (PImax) and the percentage of predicted values (%PImax) in 113 patients with COPD. Six-minute walk distance (6-MWD) was measured as an indicator of functional exercise capacity, and a 6-MWD of <350 m was defined as functional exercise intolerance. Thresholds were determined as values with high specificity (>0.90) and maximal sensitivity. Statistical significance was set at P < 0.01. RESULTS: The data of 96 patients (74 ± 6 years old; forced expiratory volume in 1-s [FEV1], 56.5 ± 26.2% predicted) were analyzed; three women and 14 participants with missing data were excluded. Multivariate logistic regression models identified significant associations of PImax (odds ratio at 99% confidence interval [CI]: 0.95 [0.92-0.98]) and %PImax (odds ratio at 99% CI: 0.97 [0.95-0.99]) with 6-MWD, after adjustments for height and FEV1. C-statistics showed that the area under the curves (99% CI) of PImax and %PImax were comparable (0.87 [0.77-0.96] and 0.83 [0.72-0.94]). The thresholds of PImax and %PImax were 45.1 cmH2O and 66%; PImax and %PImax also had moderate positive likelihood ratios of 4.44 and 5.00. CONCLUSIONS: Thresholds of inspiratory muscle strength in men with COPD could help clinicians evaluate whether their patient's inspiratory muscle strength is inadequate to achieve a 6-MWD of ≥350 m, and identify patients who should be targeted for inspiratory muscle training.

The control of respiratory pressures and neuromuscular activation to increase force production in trained martial arts practitioners.

PURPOSE: The mechanisms that explain the ability of trained martial arts practitioners to produce and resist greater forces than untrained individuals to aid combat performance are not fully understood. We investigated whether the greater ability of trained martial arts practitioners to produce and resist forces was associated with an enhanced control of respiratory pressures and neuromuscular activation of the respiratory, abdominal, and pelvic floor musculature. METHODS: Nine trained martial arts practitioners and nine untrained controls were instrumented with skin-surface electromyography (EMG) on the sternocleidomastoid, rectus abdominis, and the group formed by the transverse abdominal and internal oblique muscles (EMGtra/io). A multipair oesophageal EMG electrode catheter measured gastric (Pg), transdiaphragmatic (Pdi), and oesophageal (Pe) pressures and EMG of the crural diaphragm (EMGdi). Participants performed Standing Isometric Unilateral Chest Press (1) and Standing Posture Control (2) tasks. RESULTS: The trained group produced higher forces normalised to body mass2/3 (0.033 ± 0.01 vs. 0.025 ± 0.007 N/kg2/3 mean force in Task 1), lower Pe, and higher Pdi in both tasks. Additionally, they produced higher Pg (73 ± 42 vs. 49 ± 19 cmH2O mean Pg) and EMGtra/io in Task 1 and higher EMGdi in Task 2. The onset of Pg with respect to the onset of force production was earlier, and the relative contributions of Pg/Pe and Pdi/Pe were higher in the trained group in both tasks. CONCLUSION: Our findings demonstrate that trained martial arts practitioners utilised a greater contribution of abdominal and diaphragm musculature to chest wall recruitment and higher Pdi to produce and resist higher forces.

Inspiratory Muscle Training Program Using the PowerBreath®: Does It Have Ergogenic Potential for Respiratory and/or Athletic Performance? A Systematic Review with Meta-Analysis.

This systematic review and meta-analysis aim to provide scientific evidence regarding the effects of training on respiratory muscle training's impact with the PowerBreath®. A systematic analysis based on the PRISMA guides and a conducted research structured around the bases of Web of Science, Scopus, Medline/PubMed, SciELO y Cochrane Library Plus. Six articles published before January 2021 were included. The documentation and quantification of heterogeneity in every meta-analysis were directed through Cochran's Q test and the statistic I2; additionally, a biased publication analysis was made using funnel plots, whose asymmetry was quantified Egger's regression. The methodological quality was assessed through McMaster's. PowerBreath® administering a ≥ 15% resistive load of the maximum inspiratory pressure (PIM) achieves significant improvements (54%) in said pressure within 4 weeks of commencing the inspiratory muscle training. The maximal volume of oxygen (VO2max) considerable enhancements was achieved from the 6 weeks associated with the maximum inspiratory pressure ≥ 21.5% post inspiratory muscle training onwards. Conversely, a significant blood lactate concentration decrement occurred from the 4th week of inspiratory muscle training, after a maximum inspiratory pressure ≥ 6.8% increment. PowerBreath® is a useful device to stimulate sport performance and increase pulmonary function.

Inspiratory muscle training improves breathing pattern and sympatho-vagal balance but not spontaneous baroreflex sensitivity in older women.

Even though recent studies reported a positive inspiratory muscle training (IMT) effect on cardiovascular autonomic modulation, its underlying mechanisms as the breathing pattern remain unclear. The study aimed to investigate the IMT effects on resting heart rate variability (HRV), spontaneous baroreflex sensitivity (BRS), and spontaneous breathing pattern in older women. Fourteen healthy older women participated in this study, allocated in IMT (50 % MIP; n = 8) or Sham (5% MIP; n = 6) protocols for four weeks. Blood pressure, heart rate, and ventilatory data were continuously recorded before and after interventions. After four weeks, IMT-group increased maximal inspiratory pressure and vagal-mediated HRV, following by the reduction of sympatho-mediated HRV and the inspiratory time during the spontaneous breathing cycle compared to Sham-group, but did not change BRS. Therefore, the shorter inspiratory time suggests a putative mechanism behind improved vagal-mediated HRV post-IMT in older women.