Inspiratory Resistive Training Research Articles

Similar effects on exercise performance following different respiratory muscle training programs in healthy young men

Both respiratory muscle endurance training (RMET) and inspiratory resistive training (IMT) seem to increase whole-body exercise performance, but direct comparisons between the two are scarce. We hypothesized that the similarity of RMET to exercise-induced ventilation would induce larger improvements compared to IMT. Twenty-six moderately-trained men performed either 4 weeks of RMET, IMT or SHAM training. Before and after the interventions, respiratory muscle endurance, 3-km running time-trial performance and leg muscle fatigue after intense constant-load cycling (assessed with femoral nerve magnetic stimulation) were measured. Both RMET (+ 59%) and IMT (+ 38%) increased respiratory muscle endurance (both p < 0.01 vs. SHAM) but only IMT increased inspiratory strength (+ 32%, p < 0.001 vs. SHAM). 3-km time improved showing a main effect of training (p = 0.026), however with no differences between groups. Leg fatigue after cycling was not attenuated with training (p = 0.088 for group-training interaction). All groups showed a significant (~ 0.3 l) increase in average tidal volume during cycling exercise combined with a concomitant reduction in respiratory exertion. While RMET and IMT improved specific aspects of respiratory muscles performance, no benefits beyond SHAM were seen during whole-body exercise. Changes in respiratory sensations might be a result of altered breathing pattern.

Clinical aspects and targeted inspiratory muscle training in children and adolescents with Fontan circulation: a randomized controlled trial.

Since 1968, thousands of patients with a morphologically or functionally univentricular heart have been treated with a total cavopulmonary connection/Fontan operation. Because of the resulting passive pulmonary perfusion, blood flow is assisted by the pressure shift during respiration. Respiratory training is known to improve exercise capacity and cardiopulmonary function. However, there are limited data on whether respiratory training can also improve physical performance after Fontan surgery. The aim of the present study was to clarify the effects of six months of daily home-based inspiratory muscle training (IMT) aimed at increasing physical performance by strengthening respiratory muscles, improving lung function and peripheral oxygenation. In this non-blinded randomized controlled trial, the effects of IMT on lung capacity and exercise capacity were measured in a large cohort of 40 Fontan patients (25% female; 12.3±2.2 years) who were under regular follow-up by the outpatient clinic of the Department of Congenital Heart Defects and Pediatric Cardiology of the German Heart Center Munich. After a lung function test and a cardiopulmonary exercise test, patients were randomly assigned in a parallel arm design to either an intervention group (IG) or a control group (CG) via stratified and computer-generated letter randomization from May 2014 to May 2015. The IG completed a daily, telephone-monitored IMT of three sets of 30 repetitions for six months with an inspiratory resistive training device (POWERbreathe medic®), the CG continued their usual daily activities without an IMT until the second examination within the timeframe of November 2014 until November 2015. After six months of IMT, lung capacity values in the IG (n=18) did not increase significantly compared to the CG [n=19; ΔFVC: IG: 0.21±0.16 l vs. CG 0.22±0.31 l; P=0.946 (CI: -0.16, 0.17); ΔFEV1: CG: 0.14±0.30 vs. IG: 0.17±0.20 P=0.707 (CI: -0.20, 0.14)]. Exercise capacity did not improve significantly, yet the maximum workload achieved trended to improve with an increase of 14% in the IG vs. 6.5% in the CG [P=0.113 (CI: -15.8, 1.76)]. There was a significant increase of oxygen saturation at rest in the IG compared to the CG [IG: 3.31%±4.09% vs. CG: 0.17%±2.92%, P=0.014 (CI: -5.60, -0.68)]. Compared to the CG, the mean oxygen saturation at peak exercise no longer dropped below 90% in the IG. This observation is thus not statistically significant, yet of clinical relevance. The results of this study show benefits of an IMT in young Fontan patients. Even if some data are not statistically significant, they may still be clinically relevant and may contribute to a multidisciplinary approach in patient care. IMT should therefore be an additional target and integrated into the training program to improve the prognosis of Fontan patients. German Clinical Trials Register; DRKS.de; registration ID: DRKS00030340.

The Comparison Effect of Two Pulmonary Rehabilitation Protocols on spirometer indexes and physical performance in patients with COPD.

Background and Objective: Respiratory exercise training based on pulmonary Rehabilitation can lead to improvement of physical function and pulmonary function in COPD patients. The aim of this study was to compare the effects of different protocols of inspiratory pressure threshold loading on some spirometery indexes, physical function and dyspnea in COPD patients. Subjects and Methods: In present semi-experimental research thirty patients with moderate to severe intensity of COPD were selected targetly, and divided randomly in three groups: control (n=10), moderate intensity of inspiratory resistive training (n=10), height intensity of inspiratory resistive training (n=10). Spirometer indexes, dyspnea, and physical function base on 6MWD test were measured before and after pulmonary rehabilitation protocols. Two way ANOVA used for statistical analysis (p 0.05). After pulmonary rehabilitation periods there were no significant differences between FEV1، MVV، FEV1/FVC، VT، 6MWD, and dyspnea levels among control and intervention groups (P>0.05). Conclusion: pulmonary rehabilitation programs based on inspiratory pressure

Effect of inspiratory resistive training on diaphragm shear modulus and accessory inspiratory muscle activation.

This study aimed to elucidate changes in diaphragm and accessory inspiratory muscle (sternocleidomastoid (SCM) muscle and intercostal muscle (IC)) function after a 6-week training program. Nineteen male elite collegiate swimmers were assigned to either a control group (n = 9) or training group (n = 10). The subjects in the training group performed 30 maximum inspirations at a load resistance of 50% of maximum inspiratory mouth pressure (PImax) using an inspiratory muscle training device. These were conducted twice per day and 6 days per week. At baseline and after 6 weeks, PImax, shear modulus of the diaphragm, and electromyograms (EMG) of the SCM and IC during a maximal inspiratory maneuver were evaluated. Relative change in PImax was greater in the training group than in controls. The shear modulus during a PImax maneuver had increased significantly in both groups after 6 weeks. EMG amplitudes of the SCM increased in the training group after 6 weeks, but not in the control group. EMG amplitudes of the IC did not change after 6 weeks in either group. These results suggest that 6-week inspiratory resistive training significantly improves the activation of the SCM, which could be one of the major mechanisms behind increases in inspiratory muscle strength after resistive training. Novelty Six-week inspiratory resistive training increased diaphragm stiffness during maximal inspiration maneuver. Six-week inspiratory resistive training increased electromyogram amplitudes of the sternocleidomastoid during maximal inspiration maneuver.

Transdiaphragmatic pressure and neural respiratory drive measured during inspiratory muscle training in stable patients with chronic obstructive pulmonary disease.

PurposeInspiratory muscle training (IMT) is a rehabilitation therapy for stable patients with COPD. However, its therapeutic effect remains undefined due to the unclear nature of diaphragmatic mobilization during IMT. Diaphragmatic mobilization, represented by transdiaphragmatic pressure (Pdi), and neural respiratory drive, expressed as the corrected root mean square (RMS) of the diaphragmatic electromyogram (EMGdi), both provide vital information to select the proper IMT device and loads in COPD, therefore contributing to the curative effect of IMT. Pdi and RMS of EMGdi (RMSdi%) were measured and compared during inspiratory resistive training and threshold load training in stable patients with COPD.Patients and methodsPdi and neural respiratory drive were measured continuously during inspiratory resistive training and threshold load training in 12 stable patients with COPD (forced expiratory volume in 1 s ± SD was 26.1%±10.2% predicted).ResultsPdi was significantly higher during high-intensity threshold load training (91.46±17.24 cmH2O) than during inspiratory resistive training (27.24±6.13 cmH2O) in stable patients with COPD, with P<0.01 for each. Significant difference was also found in RMSdi% between high-intensity threshold load training and inspiratory resistive training (69.98%±16.78% vs 17.26%±14.65%, P<0.01).ConclusionWe concluded that threshold load training shows greater mobilization of Pdi and neural respiratory drive than inspiratory resistive training in stable patients with COPD.

Comparing Inspiratory Resistive Muscle Training with Incentive Spirometry on Rehabilitation of COPD Patients

To examine the effect of incentive spirometry in pulmonary rehabilitation of chronic obstructive pulmonary disease (COPD) patients and compare its efficacy with inspiratory resistive muscle training (IMT) technique. Randomized controlled trial. Thirty patients with COPD, from a general hospital in Mashhad, Iran, were randomly assigned to two study groups. All subjects trained daily in two 15-minute sessions, 4 days a week, for 4 weeks. Respiratory function tests were compared before interventions and at the end of weeks 2 and 4. Both techniques improved the mean values of all respiratory function tests (p≤.01). The IMT technique was more effective to improve MVV and PImax (p≤.05). PEFR was better improved in the incentive spirometry group (p≤.05). There was no significant difference for other spirometric parameters between two groups. Incentive spirometry can be considered as an effective component for pulmonary rehabilitation in COPD patients.

Effects of different respiratory muscle training regimes on fatigue-related variables during volitional hyperpnoea

We compared the effects of the most commonly used respiratory muscle (RM) training regimes: RM endurance training (RMET; normocapnic hyperpnoea) and inspiratory resistive training (IMT), on RM performance. Twenty-six healthy men were randomized into 3 groups performing 4 weeks of RMET, IMT or sham-training. Lung function, RM strength and endurance were tested before and after training. RM fatigue during intermittent hyperpnoea was assessed by twitch oesophageal (P(oes,tw)) and gastric pressures with cervical and thoracic magnetic stimulation. Respiratory sensations (visual analogue scale, 0-10) and blood lactate concentrations ([La]) were assessed during hyperpnoea. RMET increased maximal voluntary ventilation while IMT increased maximal inspiratory pressure. Both RMET and IMT increased vital capacity and RM endurance, but only RMET improved the development of inspiratory muscle fatigue (from -31% to -21% P(oes,tw)), perception of respiratory exertion (4.2+/-0.1 to 2.3+/-2.3 points) and [La] (1.8+/-0.4 to 1.3+/-0.3 mmol l(-1)) during hyperpnoea. Whether these specific RMET-induced adaptations observed during hyperpnoea would translate into greater improvements in exercise performance compared to IMT remains to be investigated.

Inspiratory Muscle Training: Integrative Review

This article provides a critical review of inspiratory muscle training (IMT) in chronic obstructive pulmonary disease (COPD). Although extensive research on IMT has accumulated, its benefits have been debated, primarily because of methodological limitations of studies. Using relevant key words, multiple databases were searched from 1966. Selected studies used PImax (maximal inspiratory pressure) as an outcome variable. Overall, research demonstrated that a standard protocol of 30% or higher for a duration of 20 to 30 minutes per day for 10 to 12 weeks improves dyspnea and inspiratory strength and endurance with either inspiratory resistive or inspiratory threshold training. Regardless of method, IMT protocols for people with COPD and inspiratory muscle weakness and dyspnea are generally safe, feasible, and effective. Patient selectivity and study of subgroups are recommended.

Weaning from mechanical ventilation

We used inspiratory resistive training (IRT) in an effort to improve the respiratory muscle endurance of 27 patients with respiratory failure who had failed repeated weaning attempts using standard techniques. Seven patients had primary neuromuscular diseases; the other 20 had primary lung diseases. All patients had stable respiratory failure, without gross malnutrition or electrolyte disorders. Their best initial T-piece duration averaged 6.4 +/- 8.4 (SD) h, with pHa 7.33 +/- 0.09 and PCO2 63 +/- 4 torr at the end of the T-piece trial. We provided a mean of five weekly training sessions of spontaneous breathing through an adjustable nonlinear resistor, with gradually increasing duration and resistance. When initial T-piece tolerance was less than 2 h, two to ten breaths of mechanical ventilation were provided during IRT sessions. No training session exceeded 30 min, and mechanical ventilation was provided between IRT sessions. Under this regimen, maximal inspiratory pressure improved from -37 +/- 15 to -46 +/- 15 cm H2O (p less than .001) and vital capacity improved from 561 +/- 325 to 901 +/- 480 ml (p less than .001). Twelve of the 27 patients were successfully weaned after 10 to 46 days; five more were weaned to nocturnal ventilation, for a total of 63%. We conclude that IRT can improve respiratory muscle strength and endurance in patients with respiratory failure, and can allow many of them to be weaned from mechanical ventilation.

Weaning from mechanical ventilation

An 18-yr-old man with Duchenne muscular dystrophy and ventilatory failure could not be weaned from mechanical ventilation using a T-piece method, despite repeated attempts over 3 months. Subsequently, we weaned the patient using inspiratory muscle resistive training (IRT), modified by the concurrent delivery of intermittent mandatory ventilation (IMV). During the training program, the sessions were gradually prolonged from 5 min to a maximum of 30 min, the IMV rate was gradually decreased, and the magnitude of the resistive load was gradually increased. After 45 days of training, his vital capacity had increased from 380 to 850 ml, his maximal inspiratory airway pressure from -28 to -50 cm H2O, and his tolerance of T-piece breathing, from less than 10 min to over 16 h. After an additional 2 wk of nocturnal mechanical ventilation, he was successfully weaned. We conclude that IRT with IMV can be an effective method of weaning patients who have severe ventilatory failure.

The effects of inspiratory resistive training on respiratory muscle function in patients with muscular dystrophy

The effects of inspiratory resistive training on respiratory muscle function was evaluated in 11 patients with Duchenne, limb-girdle, and facio-scapulo-humeral (FSH) type muscular dystrophy. Muscle training consisted of breathing against an inspiratory resistance for two 15-minute sessions each day while at home. Following 6 weeks of training, there were significant increases in the maximum resistance that could be tolerated for at least 5 minutes (P < 0.01) and also in the maximum duration that ventilations equal to 30%, 50%, 70%, and 90% of the maximum voluntary ventilation could be sustained (P < 0.05). In six patients who trained for an additional 6-week period, respiratory muscle endurance increased even further. The degree of improvement in respiratory muscle endurance was positively correlated with baseline vital capacity (r = 0.84, P < 0.05) and maximal inspiratory pressure (r = 0.76, P < 0.05). Spirometry, functional residual capacity, and maximal inspiratory and expiratory pressures were not affected by training. We conclude that inspiratory resistive training improves respiratory muscle endurance in muscular dystrophy patients. Improvement in respiratory muscle function may serve to delay the onset of respiratory complications in patients with muscular dystrophy.

Increased Exercise Performance in Patients with Severe COPD Following Inspiratory Resistive Training

Six patients with severe chronic obstructive pulmonary disease underwent a six-week outpatient program to train their respiratory muscles with an inspiratory resistive device. Exercise performance was measured using a cycle ergometer. Maximum exercise capacity, represented by VO2 max, increased 15 percent. The maximum work rate increased 37 percent, and the minute ventilation attained during exercise increased 17 percent after training. Respiratory muscle endurance increased 56 percent. All patients reported an increased ability to perform the activities of daily living. No changes were reported in three patients who underwent sham training.