Inspiratory Muscle Training Protocol Research Articles

Effects of different inspiratory muscle training protocols on functional exercise capacity and respiratory and peripheral muscle strength in patients with chronic kidney disease: a randomized study

BackgroundPathological changes were observed in the diaphragm due to abnormal renal function in chronic kidney disease (CKD). Inspiratory muscle training (IMT) has been suggested for patients with CKD; however, the most appropriate intensity for IMT has not been determined. Therefore, this study aimed to investigate the effects of different IMT protocols on respiratory muscle strength, quadriceps femoris muscle strength (QMS), handgrip muscle strength (HGS), functional exercise capacity, quality of life (QoL), pulmonary function, dyspnoea, fatigue, balance, and physical activity (PA) levels in patients with CKD.MethodsThis randomized, controlled, single-blind study included 47 patients and they were divided into three groups: Group 1 (n = 15, IMT with 10% maximal inspiratory pressure (MIP)), Group 2 (n = 16, IMT with 30% MIP), and Group 3(n = 16; IMT with 60% MIP). MIP, maximal expiratory pressure (MEP), 6-min walking test (6-MWT), QMS, HGS, QoL, pulmonary function, dyspnoea, fatigue, balance, and PA levels were assessed before and after eight weeks of IMT.ResultsIncreases in MIP, %MIP, 6-MWT distance, and %6-MWT were significantly higher in Groups 2 and 3 than in Group 1 after IMT (p < 0.05). MEP, %MEP, FEF25-75%, QMS, HGS, and QoL significantly increased; dyspnoea and fatigue decreased in all groups (p < 0.05). FVC, PEF, and PA improved only in Group 2, and balance improved in Groups 1 and 2 (p < 0.05).ConclusionsIMT with 30% and 60% MIP similarly improves inspiratory muscle strength and functional exercise capacity. IMT with 30% is more effective in increasing PA. IMT is a beneficial method to enhance peripheral and expiratory muscle strength, respiratory function, QoL and balance, and reduce dyspnoea and fatigue. IMT with %30 could be an option for patients with CKD who do not tolerate higher intensities.Trial registrationThis study was retrospectively registered (NCT06401135, 06/05/2024).

Comparison of two inspiratory muscle training protocols in people with spinal cord injury: a secondary analysis

Study design/settingSecondary analysis.ObjectivesTo compare the change in maximal inspiratory pressure (PImax) over the first 4 weeks of two different inspiratory muscle training (IMT) protocols and explore if either method is more effective for people with spinal cord injury.MethodsData originated from two published studies. Participants completed flow-resistive IMT (F-IMT) at 80% daily PImax, 7 days/week (supervised weekly), or threshold IMT (T-IMT) at 30–80% weekly PImax, twice-daily, 5 days/week (supervised every session). Seven participants from each trial were matched by training adherence, level of spinal cord injury, impairment grade (A–C), and height. Differences between F-IMT and T-IMT groups in training intensity, breaths taken, inspiratory work, and the change in the PImax from baseline at the end of week four were analysed.ResultsOver 4 weeks, there was no difference in the change in PImax between groups (Absolute change in PImax (cmH2O): p = 0.456, Percent change in PImax relative to baseline: p = 0.128). F-IMT participants trained at a higher intensity (median: 77 vs 22 cmH2O, p = 0.001 and 80% baseline vs 61% baseline, p = 0.038) but took fewer breaths (840 vs 1404 breaths, p = 0.017) than T-IMT participants. Inspiratory work was similar between groups (64,789 vs 65,910 (% PImax × number of breaths), p = 0.535).ConclusionsOur findings support both methods of IMT as the change in PImax and inspiratory work were similar between groups. However, daily high-intensity F-IMT with intermittent supervision, required fewer breaths and less participant and therapist time. Future studies should examine optimal dosage and supervision required to achieve increased PImax.

Characterization of Multiple Regimes of Cardiorespiratory Phase Synchronization in Athletes Undergoing Inspiratory Muscle Training.

Cardiorespiratory phase synchronization (CRPS) is defined as the stable occurrence of n heartbeats within m respiratory cycles according to the n:m phase locking ratio (PLR). Since CRPS is an intermittent phenomenon where different phase synchronization regimes and epochs of phase unlocking can alternate within the same recording, an index of CRPS ideally should assess all potential PLRs present in the recording. However, traditional approaches compute the synchronization index (SYNC%) over a single n:m PLR, namely the one that maximizes CRPS. In the present work, we tested a synchronization index assessing the total percentage of heartbeats coupled to the inspiratory onset regardless of phase locking regimes (SYNC%sum) and we compared its efficacy to the more traditional SYNC%. Analysis was carried out in a cohort of 25 male amateur cyclists (age: 20-40 yrs) undergoing inspiratory muscle training (IMT) at different intensities. CRPS was assessed before and after the IMT protocol, during an experimental condition known to modify CRPS, namely active standing (STAND). We found that after a moderate intensity IMT at 60% of the maximal inspiratory pressure, SYNC%sum could detect the decrease in CRPS following STAND. This result was not visible using the more traditional SYNC%. Therefore, we stress the significant presence of different phase locking regimes in athletes and the importance of accounting for multiple PLRs in CRPS analysis.Clinical Relevance- Multiple phase locking regimes contribute significantly to cardiorespiratory control in amateur cyclists especially after inspiratory muscle training of moderate intensity.

Effects of high intensity interval-based inspiratory muscle training in patients with heart failure: A single-blind randomized controlled trial

BackgroundGiven the promising effects of inspiratory muscle training (IMT), determining the most appropriate IMT protocol will optimize the training benefits. ObjectivesThe objective of this study was to determine the effects of high intensity interval-based inspiratory muscle training (H-IMT) on cardiovascular, pulmonary, physical, and psychosocial functions in patients with heart failure and reduced ejection fraction (HFrEF). MethodsThirty-four patients with HFrEF were randomly assigned to the H-IMT or control group for 3 days/week, 8 weeks training period. The H-IMT group performed IMT at least 70% of the maximal inspiratory pressure, whereas the control group performed unloaded IMT. Each session occurred 7 sets with a total of 21 min consisting of 2-min training and 1-min interval. Heart rate variability (HRV), arterial stiffness, respiratory muscle strength and endurance, diaphragm thickness, quadriceps strength, functional capacity, frailty, dyspnea, fatigue, disease-specific health-related quality of life (HRQoL), and generic HRQoL were evaluated at baseline and after 8 weeks training period by blinded assessors. ResultsStatistically significant between-group differences were observed in the time domain parameters of HRV, arterial stiffness, inspiratory and quadriceps muscle strength, respiratory muscle endurance, diaphragm thickness, functional capacity, frailty, dyspnea, fatigue, and disease-specific HRQoL in favor of the H-IMT group (p<0.05). ConclusionsH-IMT is an effective protocol for improving cardiac autonomic function, arterial stiffness, inspiratory and quadriceps muscle strength, respiratory muscle endurance, diaphragm thickness, functional capacity, frailty, dyspnea, fatigue, and disease-specific quality of life in patients with HFrEF. Clinical trial registrationNCT04839211

Inspiratory muscle training on quality of life and functional capacity after hospital discharge in patients submitted to coronary artery bypass grafting: A controlled clinical trial

IntroductionThere is a gap in knowledge about functional capacity and quality of life in patients undergoing coronary artery bypass grafting (CABG) after hospital discharge and the contribution of inspiratory muscle training (IMT). ObjectiveTo evaluate the influence of IMT on functional capacity and quality of life after hospital discharge of patients undergoing CABG. MethodologyClinical trial. In the preoperative period, patients assessed maximum inspiratory pressure (MIP), quality of life using the SF-36 and functional capacity using the Six-Minute Walk Test (6MWT). On the first postoperative day, they were randomized into: control group (CG) receiving routine assistance from the hospital; intervention group(IG) in addition to conventional physical therapy and submitted to an IMT protocol based on the glycemic threshold. Being reevaluated on the day of hospital discharge and post-discharge month. Results41 patients were included. In the preoperative period of the MIP assessment of the CG, it was 104 ± 14 cmH2O already in GI it was 103 ± 19cmH2O (p = 0.78) CG at discharge 80 ± 13 cmH2O already in GI it was 92 ± 15cmH2O(p < 0.01), revaluation CG 91 ± 11 cmH2O versus 98 ± 12 cmH2O (p < 0.01) of the IG. In the 6MWT the preoperative of the GC group was 420 ± 70 m already in GI it was 429 ± 71 m (p = 0,89), CG at discharge 326 ± 79 m versus 373 ± 55 m and revaluation of the CG 377 ± 75 m and IG 410 ± 57 m (p < 0.01). Functional capacity, general health status, emotional aspects and limitations due to physical aspects were significant when the three moments were compared. ConclusionIMT increases functional capacity, inspiratory muscle strength and quality of life after discharge from patients undergoing CABG.

Inspiratory muscle training, with or without concomitant pulmonary rehabilitation, for chronic obstructive pulmonary disease (COPD).

Inspiratory muscle training, with or without concomitant pulmonary rehabilitation, for chronic obstructive pulmonary disease (COPD).

Effects of inspiratory muscle training on physical performance during backpack carrying

Purpose: Restricting chest movement when carrying a loaded backpack reduces efficiency and increases the work of the respiratory muscles. The aim of the present study was to investigate the effects of six weeks of inspiratory muscle training (IMT) on respiratory muscle strength and endurance and on physical performance when carrying a load. Methods: Twenty male (age: 32.2 ± 3.4 years) members of the Special Operations Unit of the Slovenian Army volunteered to participate. The experimental group (n=10) trained their respiratory muscles for six weeks against an incremental inspiratory resistance with a breathing apparatus. The placebo group (n=10) performed the same IMT protocol but with a sham inspiratory resistance. Assessment of the subjects before and after IMT included measurements of the maximal inspiratory and expiratory pressures, heart rate measurements, and ratings of perceived physical and respiratory exertion before and after a 60-min walk test with a 25-kg backpack. Results: After six weeks of IMT, the maximum inspiratory pressure measured before and after the 60-minute walk test increased significantly (p &lt; 0.001) in the experimental group by 47 ± 13% and 58 ± 20%, respectively. Inspiratory fatigue was also significantly lower in the experimental group. No changes were observed in the heart rate and the rating of perceived exertion during the walking test. In the placebo group, no significant changes were observed in the measured parameters after IMT.Conclusion: Six weeks of IMT with progressive breathing resistance improves strength and reduces fatigue of the respiratory muscles. Individuals who perform tasks that require them to carry a heavy backpack for extended periods of time may benefit from IMT.

Long-Term Effects of Inspiratory Muscle Training in Institutionalized Elderly Women: A Double-Blind Randomized Controlled Trial

Background: Inspiratory muscle training (IMT) has been applied to different populations, but evidence in elderly women and maintenance of improvements achieved during training is scarce. The objective of the study was to evaluate the effectiveness of IMT 6 months after finishing the training period in elderly women. Methods: A controlled, randomized, double-blind trial was conducted, with allocation concealment performed on 26 institutionalized elderly women distributed into 2 groups: high loads and low loads. Over an 8-week period, an IMT protocol was followed; later, elderly women continued for 6 months with their daily normal activities. Inspiratory strength, expiratory strength, and functional capacity were measured pre-IMT, post-IMT, and 6 months after intervention. Results: After an 8-week training, respiratory strength and functional capacity increased in both groups. Six months after finishing the intervention, these benefits were lost. Inspiratory strength decreased in the high-loads group but was 32% higher than initial values (p = 0.007); in the low-loads group, patients lost 41% (p = 0.015). Improvements were higher in the high-loads group after training (p = 0.000) and follow-up (p = 0.002). Functional capacity was similar to initial values in both groups. Conclusion: The improvements achieved with IMT in elderly women disappeared 6 months after the end of training. High loads were more effective to keep inspiratory strength than low loads.

Effects of two different inspiratory muscle training devices on respiratory muscle strength, cardiopulmonary functional capacity, and quality of life of COPD patients

Inspiratory muscle weakness is one of the complications of chronic obstructive pulmonary disease (COPD). This condition has been minimized by inspiratory muscle training (IMT). Still, different IMT devices need to be compared to identify the best option. Objective: To evaluate the effects of two IMT devices on respiratory muscle strength, cardiorespiratory functional capacity, and life quality of COPD patients. Method: Before and after the IMT protocol, 17 patients were submitted to manovacuometry, six-minute walk test (6MWT), and questionnaire from the Saint George Hospital in Respiratory Disease (SGRQ) for inspiratory muscle strength, cardiorespiratory functional capacity, and life quality assessments, respectively. Afterwards, they were divided into two groups to perform IMT for four weeks, one by Threshold® IMT (IMTG) and the other by POWERbreathe® Classic (PG). Results: Maximal inspiratory pressure increased significantly from -62.00±16.03 to -75.55±22.84 cmH2O in IMTG, and from -56.00±22.01 to -71.25±27.67 cmH2O in PG. The distance covered in the 6MWT clinically increased with both IMTG and PG. The SGRQ answers showed improvements in all domains evaluated for both groups. However, the intergroup results showed no statistically significant differences. Conclusion: Both IMT devices increased inspiratory muscle strength, improved life quality, and optimized cardiorespiratory functionality in COPD patients. None was superior to the other for the analyzed parameters.

Efetividade de diferentes protocolos e cargas utilizadas no treinamento muscular inspiratório de indivíduos com DPOC: uma revisão sistemática

ABSTRACT Chronic obstructive pulmonary disease (COPD) changes the musculoskeletal system, including the respiratory muscles, which are responsible for increasing dyspnea and reducing functional capacity. Several studies have already showed the effectiveness of inspiratory muscle training (IMT); therefore, it should be part of the pulmonary rehabilitation program. However, assessing the best way to do it is still necessary. Thus, this study aimed to evaluate, by a systematic review, the effectiveness of different IMT protocols and loads on the outcomes of inspiratory muscle strength and endurance, functional capacity, and dyspnea reduction. This systematic review was performed in accordance with the PRISMA protocol. Studies were searched in February 2021 in the PubMed, SciELO, PEDro. For the search, the following keywords were used: “COPD” and “breathing exercises, resistive training, respiratory muscle training.” A total of 398 individuals previously diagnosed with COPD were included in the 10 selected studies. Different IMT devices were used and protocols varied in relation to loads and progression. Threshold was the most used IMT device. Its load was established according to the percentage of maximal inspiratory pressure (MIP) (30-80%) and readjusted according to new measurements taken every one or two weeks. Respiratory muscle training with both low loads and high loads presented positive results, however, establishing which is the best IMT protocol for individuals with COPD is not possible yet. Inspiratory muscle strength, functional capacity, and dyspnea get better with IMT.

Training the equine respiratory muscles: Inspiratory muscle strength.

Little is known about the response of the equine respiratory muscles to training. To measure an index of inspiratory muscle strength (IMSi) before and after a period of conventional exercise training (phase 1) and inspiratory muscle training (IMT), comparing high-load (treatment) and low-load (control) groups (phase 2). Prospective randomised controlled trial. Phase 1: Twenty National Hunt Thoroughbred racehorses performed an inspiratory muscle strength test (IMST) twice on two occasions; when unfit at timepoint A (July), and when race fit at timepoint B (October). Phase 2: Thirty-five Thoroughbred racehorses at race fitness were randomly assigned into a high-load (treatment, n=20) or low-load (control, n=15) IMT group. The high-load group followed an IMT protocol that gradually increased the inspiratory pressure applied every 4 days. The low-load group underwent sham IMT with a low training load. The IMT was performed 5 days/week for 10 weeks. The IMST was performed twice on two occasions, timepoint B (October) and timepoint C (January). Conventional exercise training and racing continued during the study period. The peak IMSi values obtained from the different groups at timepoints A, B and C were compared using a Wilcoxon Signed Rank Test. Phase 1: There was a significant increase in IMSi from timepoint A: 22.5 cmH2 O (21-25) to timepoint B: 26 cmH2 O (24-30) (p =0.015). Phase 2: From timepoint B to C there was a significant increase in IMSi for the high-load group 34 cmH2 O (28-36) (p =0.001) but not the low-load group 26 cmH2 O (24-30) (p =0.929). The peak IMSi at timepoint C was significantly higher for the high-load than low-load group (p =0.019). Single centre study with only National Hunt horses undergoing race-training included. In horses undergoing race training there is a significant increase in IMSi in response to conventional exercise training and high-load IMT.

Effects of two different inspiratory muscle training devices on respiratory muscle strength, cardiopulmonary functional capacity, and quality of life of COPD patients

Introduction: Inspiratory muscle weakness is one of the complications of chronic obstructive pulmonary disease (COPD). This condition has been minimized by inspiratory muscle training (IMT). Still, different IMT devices need to be compared to identify the best option. Objective: To evaluate the effects of two IMT devices on respiratory muscle strength, cardiorespiratory functional capacity, and life quality of COPD patients. Method: Before and after the IMT protocol, 17 patients were submitted to manovacuometry, six-minute walk test (6MWT), and questionnaire from the Saint George Hospital in Respiratory Disease (SGRQ) for inspiratory muscle strength, cardiorespiratory functional capacity, and life quality assessments, respectively. Afterwards, they were divided into two groups to perform IMT for four weeks, one by Threshold® IMT (IMTG) and the other by POWERbreathe® Classic (PG). Results: Maximal inspiratory pressure increased significantly from -62.00±16.03 to -75.55±22.84 cmH2O in IMTG, and from -56.00±22.01 to -71.25±27.67 cmH2O in PG. The distance covered in the 6MWT clinically increased with both IMTG and PG. The SGRQ answers showed improvements in all domains evaluated for both groups. However, the intergroup results showed no statistically significant differences. Conclusion: Both IMT devices increased inspiratory muscle strength, improved life quality, and optimized cardiorespiratory functionality in COPD patients. None was superior to the other for the analyzed parameters.

Postoperative Pulmonary Complications in Patients With Transcatheter Tricuspid Valve Implantation-Implications for Physiotherapists.

ObjectivesTo investigate the incidence of postoperative pulmonary complications (PPCs) and short-term recovery after transcatheter tricuspid valve implantation (TTVI).MethodsA total of 17 patients diagnosed with severe tricuspid regurgitation who received a LuX-valve TTVI were included in this study. Spirometry lung function, maximal inspiratory pressure (MIP), and 6-min walk test distance (6MWD) were recorded. Prior to surgery, patients were stratified into high or low pulmonary risk groups based on published predefined criteria. A physiotherapist provided all patients with education on thoracic expansion exercises, effective cough and an inspiratory muscle training protocol at 50% of MIP for 3 days preoperatively. All patients received standard post-operative physiotherapy intervention including positioning, thoracic expansion exercises, secretion removal techniques and mobilization. Patients were assessed for PPCs as defined by the Melbourne-Group Score-version 2. Clinical characteristics and hospital stay, cost, functional capacity, and Kansas City Cardiomyopathy Questionnaire (KCCQ) heart failure score were recorded at admission, 1-week, and 30-days post-op.ResultsThe mean (SD) age of the 17 patients was 68.4 (8.0) years and 15 (88%) were female. Pre-surgical assessment identified 8 patients (47%) at high risk of PPCs. A total of 9 patients (53%) developed PPCs between the 1st and 3rd day post-surgery, and 7 of these 9 patients were amongst the 8 predicted as “high risk” prior to surgery. One patient died before the 30 day follow up. Pre-operative pulmonary risk assessment score, diabetes mellitus, a low baseline MIP and 6MWD were associated with a high incidence of PPCs. Compared to those without PPCs, patients with PPCs had longer ICU and hospital stay, and higher hospitalization cost. At 30 days post-surgery, patients without PPCs maintained higher MIP and 6MWD compared to those with PPCs, but there were no significant between-group differences in other lung function parameters nor KCCQ.ConclusionThis is the first study to report the incidence of PPCs post TTVI. Despite a 3-day prehabilitation protocol and standard post-operative physiotherapy, PPCs were common among patients after TTVI and significantly impacted on hospital and short-term recovery and outcomes. In the majority of patients, PPCs could be accurately predicted before surgery. A comprehensive prehabilitation program should be considered for patients prior to TTVI.Clinical Trial Registration[www.ClinicalTrials.gov], identifier [ChiCTR2000039671].

Time to Move Beyond a "One-Size Fits All" Approach to Inspiratory Muscle Training.

Inspiratory muscle training (IMT) has been studied as a rehabilitation tool and ergogenic aid in clinical, athletic, and healthy populations. This technique aims to improve respiratory muscle strength and endurance, which has been seen to enhance respiratory pressure generation, respiratory muscle weakness, exercise capacity, and quality of life. However, the effects of IMT have been discrepant between populations, with some studies showing improvements with IMT and others not. This may be due to the use of standardized IMT protocols which are uniformly applied to all study participants without considering individual characteristics and training needs. As such, we suggest that research on IMT veer away from a standardized, one-size-fits-all intervention, and instead utilize specific IMT training protocols. In particular, a more personalized approach to an individual’s training prescription based upon goals, needs, and desired outcomes of the patient or athlete. In order for the coach or practitioner to adjust and personalize a given IMT prescription for an individual, factors, such as frequency, duration, and modality will be influenced, thus inevitably affecting overall training load and adaptations for a projected outcome. Therefore, by integrating specific methods based on optimization, periodization, and personalization, further studies may overcome previous discrepancies within IMT research.

Inspiratory Muscle Training for Obstructive Sleep Apnea: Protocol Development and Feasibility of Home Practice by Sedentary Adults

Background: Inspiratory muscle training (IMT) may improve respiratory and cardiovascular functions in obstructive sleep apnea (OSA) and is a potential alternative or adjunct treatment to continuous positive airway pressure (CPAP). IMT protocols were originally designed for athletes, however, we found some OSA patients could not perform the exercise, so we aimed for a more OSA-friendly protocol. Our feasibility criteria included (1) participants successfully managing the technique at home; (2) participants completing daily practice sessions and recording data logs; and (3) capturing performance plateaus to determine an optimal length of the intervention.Methods: Five sedentary OSA patients participated in this feasibility study (three men, mean age = 61.6 years, SD = 10.2). Using a digital POWERbreathe K4 or K5 device, participants performed 30 daily inhalations against a resistance set at a percentage of maximum, recalculated weekly. Participants were willing to perform one but not two daily practice sessions. Intervention parameters from common IMT protocols were adapted according to ability and subjective feedback. Some were unable to perform the typically used 75% of maximum inspiratory resistance so we lowered the target to 65%. The technique required some practice; therefore, we introduced a practice week with a 50% target. After an initial 8 weeks, the intervention was open-ended and training continued until all participants demonstrated at least one plateau of inspiratory strength (2 weeks without strength gain). Weekly email and phone reminders ensured that participants completed all daily sessions and logged data in their online surveys. Weekly measures of inspiratory resistance, strength, volume, and flow were recorded.Results: Participants successfully completed the practice and subsequent 65% IMT resistance targets daily for 13 weeks. Inspiratory strength gains showed plateaus in all subjects by the end of 10 weeks of training, suggesting 12 weeks plus practice would be sufficient to achieve and capture maximum gains. Participants reported no adverse effects.Conclusion: We developed and tested a 13-week IMT protocol in a small group of sedentary, untreated OSA patients. Relative to other IMT protocols, we successfully implemented reduced performance requirements, a practice week, and an extended timeframe. This feasibility study provides the basis for a protocol for clinical trials on IMT in OSA.

Inspiratory muscle training for the treatment of dynamic upper airway collapse in racehorses: A preliminary investigation

Exercise-induced upper airway collapse (UAC) probably occurs when the stabilising muscles of the upper airway are unable to withstand the dramatic changes in airflow and pressure that occurs during exercise. In racehorses, the mainstay of treatment is surgical intervention. In human athletes, exercise-induced laryngeal obstruction has been treated successfully with inspiratory muscle training (IMT). The aims of this study were: (1) to assess the feasibility of IMT in racehorses; and (2) describe the exercising endoscopy findings pre- and post-IMT in racehorses diagnosed with dynamic UAC. Horses undergoing IMT wore a mask with an attached threshold-valve to apply an additional load during inspiration, creating a training stimulus with the purpose of increasing upper airway muscle strength. Each horse underwent IMT once daily, while standing in the stable, 5–6 days/week for 10 weeks. Endoscopy recordings were analysed in a blinded manner using an objective grading scheme and subjective pairwise analysis.Seventeen horses successfully completed the IMT protocol, with full information available for 10 horses. Objective grading analysis showed a lower grade of vocal fold collapse (6/9 horses), palatal instability (7/10 horses) and intermittent dorsal displacement of the soft palate (5/7 horses) post-IMT. Pairwise subjective analysis suggested better overall airway function post-IMT in 3/10 horses. The main limitations of this preliminary investigation were the low number of horses examined and lack of a control population. Further research is required to investigate the effects of IMT on upper airway muscle strength and to evaluate its efficacy for prevention and treatment of UAC.

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.

Efficacy of inspiratory muscle training on inspiratory muscle function, functional capacity, and quality of life in patients with asthma: A randomized controlled trial

Objective: To evaluate the efficacy of an inspiratory muscle training protocol on inspiratory muscle function, functional capacity, and quality of life in patients with asthma. Design: A single-blind, randomized controlled clinical trial. Setting: Community-based. Subjects: Patients with asthma, aged between 20 and 70 years old, non-smokers. Interventions: Participants were randomized into two groups: inspiratory muscle training group performed inspiratory muscle training 5 days a week for 8 weeks, consisting of six sets of 30 breaths per day with a training load ⩾50% of maximal inspiratory pressure, plus an educational program; the control group only received the educational program. Main measurements: Maximal inspiratory pressure, inspiratory muscle endurance, and the distance performed on the incremental shuttle walking test were assessed pre-intervention, post-intervention and at follow-up (3 months after the end of the intervention). The asthma quality of life questionnaire was applied pre and post-intervention. Results: Data from 39 participants were analyzed. Maximal inspiratory pressure in percentage of predicted and endurance test duration were significantly higher post-intervention in the inspiratory muscle training group (∆ post–pre: 50.8% vs 7.3% of predicted – P < 0.001 and ∆ post–pre: 207.9 seconds vs 2.7 seconds – P < 0.001, respectively). There was no significant difference in the incremental shuttle walking distance between groups (∆ post–pre: 30.9 m vs −8.1 m, P = 0.165). Quality of life was perceived as significantly better, without a difference between groups (P > 0.05). Conclusions: About 8 weeks of inspiratory muscle training in patients with controlled asthma significantly increased inspiratory muscle strength and endurance.

Comparison between Two Inspiratory Muscle Training Protocols, Low Loads versus High Loads, in Institutionalized Elderly Women: A Double-Blind Randomized Controlled Trial

Background: Aging results in a decline in the function of the respiratory muscles. Inspiratory muscle training is presented as a possible solution to attenuate the loss of respiratory function in the elderly. The objective of the study was to evaluate and compare the efficacy of 2 protocols with inspiratory muscle training (IMT), low loads and high loads, to improve respiratory strength, functional capacity and dyspnea in institutionalized elderly women, over 65 years. Methods: The study was a controlled, randomized, double-blind trial and with allocation concealment performed on 26 institutionalized elderly women distributed in 2 groups, the high-intensity group (HIG) and low-intensity group (LIG). Over an 8-week period an IMT protocol was followed 5 days/week, 15 min/day. The HIG trained with a load of 40% of the maximum inspiratory pressure (MIP) and the LIG with 20%. MIP, maximum expiratory pressure (MEP), functional capacity and dyspnea were evaluated. Results: After training, in the HIG MIP, MEP and functional capacity increased 52, 16 and 7%, respectively (p = 0.000, p = 0.001, p = 0.001) and in the LIG 30, 18 and 9%, respectively (p = 0.002, p = 0.014, p = 0.001). The improvement in MIP was significantly higher in the HIG than in the LIG (p = 0.042). Conclusion: IMT with low and high loads improves respiratory muscle strength and functional capacity in institutionalized elderly women. In addition, high loads were significantly more effective to improve MIP.

Inspiratory Muscle Training Improves Aerobic Capacity in Amateur Indoor Football Players.

Inspiratory muscle training represents a recommended clinical practice to improve physical performance of healthy individuals, athletes, and those with chronic diseases. This study aimed to evaluate whether high- and low-intensity inspiratory muscle training interferes with the aerobic capacity of indoor soccer players. Volunteers were equally and randomly divided into CON (control group, no inspiratory muscle training); HIG (high-intensity group, inspiratory muscle training at 80% of maximal inspiratory pressure, 3 sets of 12 repetitions); and LIG (low-intensity group, inspiratory muscle training at 50% of maximal inspiratory pressure, 2 sets of 20 repetitions). Before and after inspiratory muscle training, maximal inspiratory and expiratory pressures, the incremental shuttle run test, and the 3-min step test were evaluated. Both inspiratory muscle training protocols improved maximal inspiratory and expiratory pressures, and indirect maximal oxygen consumption and distance traveled in the shuttle test compared to CON. However, only HIG achieved significant increases of indirect oxygen consumption and frequency of step rise in the 3-min step test (p<0.05). Inspiratory muscle training is an important tool to enhance maximal inspiratory pressure and exercise tolerance with potential benefits on submaximal aerobic capacity. However, high-intensity inspiratory muscle training improved aerobic capacity in amateur indoor soccer players in both submaximal tests.