Effect of Respiratory Muscle Training on Exercise Performance in Healthy Individuals

Effectiveness of Respiratory Muscles Training by Voluntary Isocapnic Hyperpnea Versus Inspiratory Threshold Loading on Intercostales and Vastus Lateralis Muscles Deoxygenation Induced by Exercise in Physically Active Adults

Respiratory muscle training (RMT) improves physical performance, although it is still debated whether this effect depends on the type of training. The purpose of this study was to compare the effects of two different types of RMT, i.e., voluntary isocapnic hyperpnea (VIH) and inspiratory threshold loading (ITL), on the deoxygenation of intercostal (ΔSmO₂-m. intercostales) and vastus lateralis (ΔSmO₂-m. vastus lateralis) muscles during exercise. Twenty-four participants performed eight weeks of RMT by: (i) VIH (3 days·week^-1 for 12 min at 60% maximal voluntary ventilation) or (ii) ITL (5 sets·week^-1 of 30 breaths·minute^-1 at 60% maximal inspiratory pressure). Cardiopulmonary exercise testing (CPET) included ΔSmO₂ (the change from baseline to end of test) of intercostal and vastus lateralis muscles. After RMT, both groups showed decreased ΔSmO₂-m. intercostales (VIH = 12.8 ± 14.6%, p = 0.04 (effect size, ES = 0.59), and ITL = 8.4 ± 9.8%, p = 0.04 (ES = 0.48)), without a coincident change of ∆SmO_2-m. vastus lateralis. ITL training induced higher V˙O_2-peak absolute values than VIH (mean Δ post-pre, ITL = 229 ± 254 mL·min^-1 [95% CI 67-391] vs. VIH, 39 ± 153 mL·min^-1 [95% CI -58-136.0], p = 0.01). In conclusion, both RMT improved the balance between supply and oxygen consumption levels of m. intercostales during CPET, with ITL also inducing an increase of aerobic capacity.

A short course of high-resistance, low-volume breathing exercise extends respiratory endurance and blunts cardiovascular responsiveness to constant load respiratory testing in healthy young adults

Our objective was to evaluate the effects of 6-weeks high-resistance, low-volume inspiratory muscle strength training (IMST) on respiratory endurance, blood pressure (BP) and heart rate (HR) responsiveness to high respiratory workloads. Ten healthy young adults completed two constant-load resistive breathing tests to exhaustion (T_lim) (target pressure =65 % maximal inspiratory pressure [PI_max]; duty cycle = 0.7; breathing frequency matched to eupnea) separated by 6-weeks high-resistance (75 % maximal inspiratory pressure, PI_max), low-volume (30 inspiratory efforts/day, 5 days/week) IMST. Throughout resistive breathing trials we measured beat-to-beat changes in BP and HR, mouth pressure, inspiratory muscle work and perceived exertion. POST resistive breathing tests revealed significant gains in endurance (PRE: 362.0 ± 46.6 s vs. POST: 663.8 ± 110.3 s, p = 0.003) and increases in respiratory muscle work (PRE: -9445 ± 1562 mmHg.s vs. POST: -16648 ± 3761 mmHg.s, p = 0.069). Conversely, systolic and diastolic BP responses, HR and ratings of perceived exertion all declined. Consistent with previous observations, 6 weeks high resistance, low volume IMST lowered casual resting SBP (p = 0.002), DBP (p = 0.007) and mean arterial pressure (p = 0.001) and improved static inspiratory pressure. High resistance, low volume inspiratory muscle strength training extends respiratory endurance and attenuates BP responsiveness in healthy, recreationally-active young adults. The outcomes have implications for improved athletic performance and for attaining and/or maintaining cardiorespiratory fitness.

Effect of a home-based inspiratory muscle training programme on functional capacity in postdischarged patients with long COVID: the InsCOVID trial

BACKGROUND

Fatigue and exercise intolerance are the most common symptoms in patients with long COVID.

AIMS

This study aimed to evaluate whether a home-based inspiratory muscle training (IMT) programme improves maximal functional capacity in patients' long COVID after a previous admission due to SARS-CoV-2 pneumonia.

METHODS

This study was a single-centre, blinded assessor, randomised controlled trial. Twenty-six patients with long COVID and a previous admission due to SARS-CoV-2 pneumonia were randomly assigned to receive either a 12-week IMT or usual care alone (NCT05279430). The physiotherapist and participants were not blinded. Patients allocated to the IMT arm were instructed to train at home twice daily using a threshold inspiratory muscle trainer and to maintain diaphragmatic breathing during the training session. The usual care arm received no intervention.The primary endpoint was the change in peak oxygen consumption (peakVO2). Secondary endpoints were changes in quality of life (QoL), ventilatory efficiency and chronotropic response during exercise (evaluated by chronotropic index-CI_x- formula). We used linear mixed regression analysis for evaluating changes in primary and secondary endpoints.

RESULTS

The mean age of the sample and time to first visit after discharge were 50.4±12.2 years and 362±105 days, respectively. A total of 11 (42.3%) were female. At baseline, the mean of peakVO₂, ventilatory efficiency and CIx were 18.9±5 mL/kg/min, 29.4±5.2 and 0.64±0.19, respectively. The IMT arm improved their peakVO₂ significantly compared with usual care (+Δ 4.46 mL/kg/min, 95% CI 3.10 to 5.81; p<0.001). Similar positive findings were found when evaluating changes for CI_x and some QoL dimensions. We did not find significant changes in ventilatory efficiency.

CONCLUSION

In long COVID patients with a previous admission due to SARS-CoV-2 pneumonia, IMT was associated with marked improvement in exercise capacity and QoL.

TRIAL REGISTRATION NUMBER

NCT05279430.

Effects of Inspiratory Muscle Training on Muscle Oxygenation during Vascular Occlusion Testing in Trained Healthy Adult Males

Inspiratory muscle training (IMT) may have an additional effect on cardiovascular autonomic modulation, which could improve the metabolism and vascular function of the muscles.

AIM

To determine the effects of IMT on vascular and metabolic muscle changes and their relationship to changes in physical performance.

METHODS

Physically active men were randomly placed into an experimental (IMTG; n = 8) or IMT placebo group (IMTPG; n = 6). For IMT, resistance load was set at 50% and 15% of the maximum dynamic inspiratory strength (S-Index), respectively. Only the IMTG's weekly load was increased by 5%. In addition, both groups carried out the same concurrent training. Besides the S-Index, a 1.5-mile running test, spirometry, and deoxyhemoglobin (HHb_AUC during occlusion) and reperfusion tissue saturation index (TSI_MB and TSI_MP: time from minimum to baseline and to peak, respectively) in a vascular occlusion test were measured before and after the 4-week training program. In addition, resting heart rate and blood pressure were registered.

RESULTS

IMTG improved compared to IMTPG in the S-Index (Δ = 28.23 ± 26.6 cmH₂O), maximal inspiratory flow (MIF: Δ = 0.91 ± 0.6 L/s), maximum oxygen uptake (Δ = 4.48 ± 1.1 mL/kg/min), 1.5-mile run time (Δ = -0.81 ± 0.2 s), TSI_MB (Δ = -3.38 ± 3.1 s) and TSI_MP (Δ = -5.88 ± 3.7 s) with p < 0.05. ΔVO_2max correlated with S-Index (r = 0.619) and MIF (r = 0.583) with p < 0.05. Both ΔTSI_MB and TSI_MP correlated with ΔHHb_AUC (r = 0.516 and 0.596, respectively) and with Δ1.5-mile run time (r = 0.669 and 0.686, respectively) with p < 0.05.

CONCLUSION

IMT improves vascular function, which is related to additional improvements in physical performance.

Acute psychophysiological responses during exercise while using resistive respiratory devices: A systematic review

Different studies have observed that respiratory muscle training (RMT) improve the endurance and strength of the respiratory muscles, having a positive impact on performance of endurance sports. Nevertheless, it remains to be clarified how to improve the efficiency of such training. The objective of this systematic review was to evaluate the acute physiological responses produced by training the respiratory muscles during exercise with flow resistive devices because such information may support us improve the efficiency of this type of training. A search in the Medline, Science Direct, Web of Science and Scopus databases was conducted, following the PRISMA guidelines. The methodological quality of the articles was assessed using the PEDro scale. Nineteen studies met the inclusion criteria and a total of 212 subjects were included in the studies. The RMT method used in all studies was flow resistive loading, whereas the constant load exercise was the most common type of exercise among the studies. The results obtained seem to indicate that the use of this type of training during exercise reduces the performance, the lactate (La^-) values and the ventilation, whereas the end - tidal partial pressure of carbon dioxide (P_CO2) is increased.

Resistance Training Combined With Cognitive Training Increases Brain Derived Neurotrophic Factor and Improves Cognitive Function in Healthy Older Adults

Background

The present study compared the effects of a traditional resistance training (TRT) and resistance training combined with cognitive task (RT + CT) on body composition, physical performance, cognitive function, and plasma brain-derived neurotrophic factor (BNDF) levels in older adults.

Methods

Thirty community-dwelling older adults were randomized into TRT (70.0 ± 8.1; 25% men) and RT + CT (66.3 ± 4.6; 31% men). Exercise groups performed a similar resistance training (RT) program, twice a week over 16 weeks. Cognitive Training involved performing verbal fluency simultaneously with RT. Exercise sessions (eight resistance exercises) were performed 2–3 sets, 8–15 repetitions at 60%–70% of 1-repetition maximum (1RM). Body composition, physical function, cognitive performance, and BDNF levels were assessed before and after intervention period.

Results

The physical performance was similarly improved in response to both TRT and RT + CT (p = 0.001). However, exclusive improvements on cognitive function (p < 0.001) and BDNF levels (p = 0.001) were observed only after RT + CT.

Conclusion

The RT program associated with a cognitive task, improved physical and cognitive performance in healthy older adults.

Effects of inspiratory muscle training in patients with obstructive sleep apnoea syndrome: a systematic review and meta-analysis

Obstructive sleep apnoea (OSA) is a common disorder marked by repetitive occurrence of breathing cessation during sleep due to partial or complete upper airway obstruction. An obstructive airway and the successive asphyxia chronically overload the inspiratory muscles resulting in an increased inspiratory effort. The present systematic review aimed to examine the effects of inspiratory muscle training (IMT) on inspiratory muscle strength [maximal inspiratory pressure (PImax)], severity of disease [apnea hypopnoea index (AHI)], sleep quality [Pittsburgh sleep quality index (PSQI)], day time sleepiness [Epworth sleepiness scale (ESS)], lung function [forced expiratory volume in 1 second (FEV1)] and exercise capacity [cardiopulmonary exercise testing, (CPET), 6 minute walk test, (6MWT)] in mild to severe OSA. Among 953 articles retrieved from various databases (PubMed, SCOPUS, Web of Science and Cochrane), 7 articles were found to be eligible for the present review. Randomized controlled trials reporting the effect of IMT in OSA were selected. The quality assessment was conducted using Cochrane risk-of-bias tool for randomized trials. All seven studies were meta-analyzed. The result depicted significant change in PImax, ES 1.73 (95%CI 0.54 to 2.92, p=0.004), PSQI -1.29 (95%CI -1.94 to -0.65, p<0.0001), ESS -1.08 (95% CI -1.79 to - 0.37, p=0.003) and FEV1 0.74 (95%CI 0.20 to 1.28, p=0.007). IMT may be considered as an effective treatment strategy in mild to severe OSA resulting in improved inspiratory muscle strength, sleep quality, daytime sleepiness, and lung function. However, there is still dearth evidence on repercussion of IMT on lung function and exercise capacity and warrants high quality evidence to reach definitive conclusions.

JD. RespiCo: A novel, flexible, and stand-alone electronic respiratory coaching device

Conscious respiratory pattern and rate control is desired by patients with some forms of pulmonary disease that are undergoing respiratory muscle conditioning and rehabilitation, by practitioners of meditation hoping to improve mindfulness and wellbeing, by athletes striving to obtain breathing control in order to increase competitiveness, and by engineers and scientists that wish to use the data from breathing subjects to test hypotheses and develop physiological monitoring systems. Although prerecorded audio sources and computer applications are available that guide breathing exercises, they often suffer from being inflexible and allow only limited customization of the breathing cues. Here we describe a small, lightweight, battery-powered, microprocessor-based respiratory coaching device (RespiCo), which through wireless or wired connections, can be easily customized to precisely guide subjects to breathe at desired respiratory rates using specific breathing patterns through visual, auditory, or haptic cues. Digital signals can also be captured from the device to document the breathing cues provided by the device for research purposes. It is anticipated that this device will have important utility for those who wish to be guided to breathe in a precise manner or in research and development of physiologic monitoring systems.

Respiratory muscle endurance training improves exercise performance but does not affect resting blood pressure and sleep in healthy active elderly

Purpose

Ageing is associated with increased blood pressure (BP), reduced sleep, decreased pulmonary function and exercise capacity. The main purpose of this study was to test whether respiratory muscle endurance training (RMET) improves these parameters.

Methods

Twenty-four active normotensive and prehypertensive participants (age: 65.8 years) were randomized and balanced to receive either RMET (N = 12) or placebo (PLA, N = 12). RMET consisted of 30 min of volitional normocapnic hyperpnea at 60% of maximal voluntary ventilation while PLA consisted of 1 inhalation day⁻¹ of a lactose powder. Both interventions were performed on 4–5 days week⁻¹ for 4–5 weeks. Before and after the intervention, resting BP, pulmonary function, time to exhaustion in an incremental respiratory muscle test (incRMET), an incremental treadmill test (IT) and in a constant-load treadmill test (CLT) at 80% of peak oxygen consumption, balance, sleep at home, and body composition were assessed. Data was analyzed with 2 × 2 mixed ANOVAs.

Results

Compared to PLA, there was no change in resting BP (independent of initial resting BP), pulmonary function, IT performance, sleep, body composition or balance (all p > 0.05). Performance significantly increased in the incRMET (+ 6.3 min) and the CLT (+ 3.2 min), resulting in significant interaction effects (p < 0.05).

Conclusion

In the elderly population, RMET might be used to improve respiratory and whole body endurance performance either as an adjunct to physical exercise training or as a replacement thereof for people not being able to intensively exercise even if no change in BP or sleep may be expected.

The rationale of applying inspiratory/expiratory muscle training within the same respiratory cycle in children with bronchial asthma: A placebo-controlled randomized clinical investigation

Objective: Even though positive implications of inspiratory muscle training (In-MT) have been established in children and adolescents with bronchial asthma (C/AwBA), the role of combined inspiratory and expiratory muscle training (Ex-MT) within the same respiratory cycle (In/Ex-SC) is still unknown. This study was, therefore, set out to explore the effect of In/Ex-SC on respiratory muscle strength, pulmonary functions, and control of asthma symptoms in C/AwBA.Methods: This was a placebo-controlled randomized clinical investigation that included 51 C/AwBA (12-18 years). Participants were assigned randomly into three groups: Placebo, In-MT only, or combined In/Ex-SC training (n = 17, each group). The training was conducted for ∼35 min, thrice/week over 12 weeks. The maximal inspiratory (IP_max) and expiratory (EP_max) pressure (indicating the strength of the inspiratory and expiratory muscles, respectively), pulmonary functions [forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), and FEV₁/FVC index], and asthma control test (ACT) were assessed before and after the intervention.Results: The In/Ex-SC yielded larger increases in IP_max and EP_max than either the Placebo training (P=.031 and P=.009 respectively) or the In-MT (P=.029 and P=.032 respectively). Further, In/Ex-SC produced favorable improvement in FEV₁, FVC, and FEV₁/FVC compared to the Placebo training (P=.001, P=.004, and P=.0005 respectively) or In-MT (P=.038, P=.037, and P=.025 respectively) training. Furthermore, In/Ex-SC led to better control of asthma symptoms than the Placebo (P<.001) or In-MT (P=.002) training.Conclusion: This study provides evidence that combined In/Ex-SC can considerably improve respiratory muscle strength, enhance pulmonary function, and promote control over asthma symptoms in C/AwBA.

Effects of different inspiratory muscle warm-up loads on mechanical, physiological and muscle oxygenation responses during high-intensity running and recovery

Inspiratory muscle warm-up (IMW) has been used as a resource to enhance exercises and sports performance. However, there is a lack of studies in the literature addressing the effects of different IMW loads (especially in combination with a shorter and applicable protocol) on high-intensity running and recovery phase. Thus, this study aimed to investigate the effects of three different IMW loads using a shorter protocol on mechanical, physiological and muscle oxygenation responses during and after high-intensity running exercise. Sixteen physically active men, randomly performed four trials 30 s all-out run, preceded by the shorter IMW protocol (2 × 15 breaths with a 1-min rest interval between sets, accomplished 2 min before the 30 s all-out run). Here, three IMW load conditions were used: 15%, 40%, and 60% of maximal inspiratory pressure (MIP), plus a control session (CON) without the IMW. The force, velocity and running power were measured (1000 Hz). Two near-infrared spectroscopy (NIRS) devices measured (10 Hz) the muscle’s oxygenation responses in biceps brachii (BB) and vastus lateralis (VL). Additionally, heart rate (HR) and blood lactate ([Lac]) were also monitored. IMW loads applied with a shorter protocol promoted a significant increase in mean and minimum running power as well as in peak and minimum force compared to CON. In addition, specific IMW loads led to higher values of peak power, mean velocity (60% of MIP) and mean force (40 and 60% of MIP) in relation to CON. Physiological responses (HR and muscles oxygenation) were not modified by any IMW during exercise, as well as HR and [Lac] in the recovery phase. On the other hand, 40% of MIP presented a higher tissue saturation index (TSI) for BB during recovery phase. In conclusion, the use of different loads of IMW may improve the performance of a physically active individual in a 30 s all-out run, as verified by the increased peak, mean and minimum mechanical values, but not in performance assessed second by second. In addition, 40% of the MIP improves TSI of the BB during the recovery phase, which can indicate greater availability of O₂ for lactate clearance.

Complex Network Model Reveals the Impact of Inspiratory Muscle Pre-Activation on Interactions among Physiological Responses and Muscle Oxygenation during Running and Passive Recovery

Simple Summary

Different warm-ups can be used to improve physical and sports performance. Among these strategies, we can include the pre-activation of the inspiratory muscles. Our study aimed to investigate this pre-activation model in high-intensity running performance and recovery using an integrative computational analysis called a complex network. The participants in this study underwent four sessions. The first and second sessions were performed to explain the procedures, characterize them and determine the individualized pre-activation intensity (40% of the maximum inspiratory pressure). Subsequently, on different days, the subjects were submitted to high-intensity tethered runs on a non-motorized treadmill with monitoring of the physiological responses during and after this effort. To understand the impacts of the pre-activation of inspiratory muscles on the organism, we studied the centrality metrics obtained by complex networks, which help in the interpretation of data in a more integrated way. Our results revealed that the graphs generated by this analysis were altered when inspiratory muscle pre-activation was applied, emphasizing muscle oxygenation responses in the leg and arm. Blood lactate also played an important role, especially after our inspiratory muscle strategy. Our findings confirm that the pre-activation of inspiratory muscles promotes modulations in the organism, better integrating physiological responses, which could increase performance and improve recovery.

Abstract

Although several studies have focused on the adaptations provided by inspiratory muscle (IM) training on physical demands, the warm-up or pre-activation (PA) of these muscles alone appears to generate positive effects on physiological responses and performance. This study aimed to understand the effects of inspiratory muscle pre-activation (IM_PA) on high-intensity running and passive recovery, as applied to active subjects. In an original and innovative investigation of the impacts of IM_PA on high-intensity running, we proposed the identification of the interactions among physical characteristics, physiological responses and muscle oxygenation in more and less active muscle to a running exercise using a complex network model. For this, fifteen male subjects were submitted to all-out 30 s tethered running efforts preceded or not preceded by IM_PA, composed of 2 × 15 repetitions (1 min interval between them) at 40% of the maximum individual inspiratory pressure using a respiratory exercise device. During running and recovery, we monitored the physiological responses (heart rate, blood lactate, oxygen saturation) and muscle oxygenation (in vastus lateralis and biceps brachii) by wearable near-infrared spectroscopy (NIRS). Thus, we investigated four scenarios: two in the tethered running exercise (with or without IM_PA) and two built into the recovery process (after the all-out 30 s), under the same conditions. Undirected weighted graphs were constructed, and four centrality metrics were analyzed (Degree, Betweenness, Eigenvector, and Pagerank). The IM_PA (40% of the maximum inspiratory pressure) was effective in increasing the peak and mean relative running power, and the analysis of the complex networks advanced the interpretation of the effects of physiological adjustments related to the IM_PA on exercise and recovery. Centrality metrics highlighted the nodes related to muscle oxygenation responses (in more and less active muscles) as significant to all scenarios, and systemic physiological responses mediated this impact, especially after IM_PA application. Our results suggest that this respiratory strategy enhances exercise, recovery and the multidimensional approach to understanding the effects of physiological adjustments on these conditions.

Stimulation of both inspiratory and expiratory muscles versus diaphragm-only paradigm for rehabilitation in severe chronic obstructive pulmonary disease patients: a randomized controlled pilot study

BACKGROUND

Chronic obstructive pulmonary disease (COPD), a progressive lung disease, might improve with neuromuscular electrical stimulation. No trials on inspiratory plus expiratory neuromuscular electrical stimulation have been conducted yet.

AIM

The aim of this study was to evaluate the safety and effectiveness of inspiratory plus expiratory neuromuscular electrical stimulation in subjects with severe COPD.

DESIGN

This was a multicenter, prospective, randomized controlled trial.

SETTING

The subjects were outpatients enrolled from Beijing Chao-Yang Hospital affiliated with Capital Medical University, Tianjin Chest Hospital, and the First Hospital of Hebei Medical University.

POPULATION

Subjects had stable COPD with severe respiratory impairment.

METHODS

Using a computer statistical software, 120 stable subjects were randomly allocated (1:1) to receive inspiratory plus expiratory neuromuscular electrical stimulation (study group) and diaphragm pacing (control group). Demographic and clinical data were collected before, and after 2, and 4 weeks of the trial. The intention-to-treat analysis was conducted. The primary outcome was to analyze the changes in functional exercise capacity, estimated as six-minute walk distance (6MWD), following electrical stimulation for 4 weeks. The secondary outcomes were changes in modified Medical Research Council score, forced expiratory volume in 1 second (FEV<inf>1</inf>), FEV<inf>1</inf>% predicted, and FEV<inf>1</inf> ratio forced vital capacity (FEV<inf>1</inf>/FVC) following electrical stimulation for 4 weeks.

RESULTS

The change in 6MWD was greater in the study group (65.53±39.45 m) than in the control group (26.66±32.65 m). The mean between-group difference at the fourth week was 29.07 m (95% confidence interval, 16.098-42.035; P<0.001). There were no significant between-group differences in the secondary outcomes after 4 weeks of electrical stimulation. For GOLD-4 COPD subjects, FEV<inf>1</inf> and FEV<inf>1</inf>/FVC improved in the study group (P<0.05). No electrical stimulation-related serious adverse events were observed in either group.

CONCLUSIONS

6MWD were increased significantly, without adverse events, after four weeks of treatment of inspiratory plus expiratory neuromuscular electrical stimulation in stable patients with severe COPD, suggesting that this protocol benefits COPD rehabilitation.

CLINICAL REHABILITATION IMPACT

The results of this study suggest that the simultaneous use of inspiratory plus expiratory neuromuscular electrical stimulation as an adjunct therapy may improve the functional exercise capacity of severe stable COPD subjects.

Outcome of survivors of COVID-19 in the intermediate phase of recovery: A case report

Introduction

Coronavirus disease 2019 (COVID-19) is a viral respiratory disease and is associated with significant morbidity in the intermediate and chronic phases of recovery from the disease. The health benefits of respiratory and extremity muscle strengthening exercise therapy are well-described for those with cardiac failure and interstitial lung disease and are suggested to improve functional ability for patients recovering from COVID-19. The aim of this case report is to share the effects of standard physiotherapy management on exercise endurance, respiratory function and return to work, implemented for patients with COVID-19 in the intermediate phase of their recovery.

Patient presentation

Two cases of COVID-19 were admitted to a private healthcare facility in Johannesburg. They presented with shortness of breath and decreased endurance. One had COVID-19 myocarditis and the other chronic post-COVID-19 organising pneumonia with pulmonary fibrosis.

Management and outcome

Both patients were admitted to ICU, provided oxygen therapy and supportive care as well as physiotherapy management in hospital and after hospital discharge. Physiotherapy management included inspiratory muscle training therapy, and cardiovascular and resistance exercise therapy. Improvements in peak expiratory flow rate and six-minute walk distance were observed for both cases at 6- and 7-months follow-up, respectively.

Conclusion

Our case report illustrates the value of ongoing physiotherapy management, utilising progressive exercise therapy prescription, to aid the return to optimal functioning for survivors of COVID-19 in the intermediate phase of their recovery.

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.

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.

A new variety of chondrocoracoideus muscle, or an additional head of pectoralis major muscle

The pectoralis major and pectoralis minor muscles are located in the anterior chest wall. This region is characterized by high morphological variability. During dissection an additional muscle was found, originating from the lateral border of the pectoralis major muscle. After fusion it passed into the tendinous part coursing under the insertion of the pectoralis major muscle, then formed a common junction with the short head of the biceps brachii muscle, the distal attachment of which is on the coracoid process. Such an accessory structure could lead to neurovascular compression and cause thoracic outlet syndrome, of which pain is usually the first symptom. This muscle has not been described in the literature so far and for that reason we can name the present case as an unique structure.

Effect of Threshold Inspiratory Muscle Training on Functional Fitness and Respiratory Muscle Strength Compared to Incentive Spirometry in Children and Adolescents With Obesity: A Randomized Controlled Trial

BACKGROUND

To determine the effect of threshold inspiratory muscle training (IMT) on functional fitness and respiratory muscle strength (RMS) compared to incentive spirometry (IS) in children/adolescents with obesity.

METHODS

A total of 60 obese children/adolescents aged 8-15 years were randomized into the threshold IMT group (n = 20), the IS group (n = 20), or the control group (n = 20). The IMT group performed 30 inspiratory breaths with the intensity set at 40% of baseline maximal inspiratory pressure (MIP) twice daily for 8 weeks; the IS group performed 30 breaths with sustained maximum inspiration twice daily for 8 weeks; and, the control group was assigned no training device for 8 weeks. Six-min walk test (6-MWT), RMS, and spirometry were compared between baseline and 8 weeks.

RESULTS

Six-MWT distance (528.5 ± 36.2 vs. 561.5 ± 35.2 m, p = 0.002) and MIP (121.2 ± 26.8 vs. 135.3 ± 32.1%Predicted, p = 0.03) were significantly improved after 8 weeks of IMT training. There was no significant difference in any evaluated pulmonary function parameters between baseline and 8 weeks in the IS or control groups; however, 6-MWT distance demonstrated a trend toward significant improvement in the IS group (526.9 ± 59.1 vs.549.0 ± 50.6 m, p = 0.10). No significant difference among groups was found for any variable relative to change from baseline to post-training.

CONCLUSION

Eight weeks of threshold IMT training significantly improved both inspiratory muscle strength (MIP) and functional fitness (6-MWT) in children/adolescents with obesity. Eight weeks of IS training yielded a trend toward significantly improved functional fitness.

Stroke and breathing

Stroke remains a leading cause of neurologic disability with wide ranging effects, including a variety of respiratory abnormalities. Stroke may influence the central control of the respiratory drive and breathing pattern, airway protection and maintenance, and the respiratory mechanics of inspiration and expiration. In the acute phase of stroke, the central control of breathing is affected by changes in consciousness, cerebral edema, and direct damage to brainstem respiratory centers, resulting in abnormalities in respiratory pattern and loss of airway protection. Common acute complications related to respiratory dysfunction include dysphagia, aspiration, and pneumonia. Respiratory control centers are located in the brainstem, and brainstem stroke causes specific patterns of respiratory dysfunction. Depending on the exact location and extent of stroke, respiratory failure may occur. While major respiratory abnormalities often improve over time, sleep-disordered breathing remains common in the subacute and chronic phases and worsens outcomes. Respiratory mechanics are impaired in hemiplegic or hemiparetic stroke, contributing to worse cardiopulmonary health in stroke survivors. Interventions to address the respiratory complications are under researched, and further investigation in this area is critical to improving outcomes among stroke survivors.

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.

Influence of Imagery Training on Adjusting the Pressure of Fin Swimmers, Improving Sports Performance and Stabilizing Psychological Quality

This study analyzed the effects of imagery training on athletes' imagery ability, physical anxiety and athletic performance. This study employed a mixed research approach. Snowball sampling was used to select 55 fin swimmers with imagery training experience and formal competition participation. Basic statistics were obtained, and Pearson product-moment correlation coefficient (PPMCC) analysis was performed using IBM SPSS Statistics for Windows, Version 26.0, and the results were compared with the opinions of three experts and were tested using multivariate validation methods. The results revealed that although imagery training can help athletes improve their performance and significantly reduce their anxiety during the competition, athletes can still make mistakes due to internal and environmental factors and even have negative thoughts that lead to their reduced likelihood of competition participation. By strengthening strategic and technical imagery training, we can help our fin swimmers perform at a higher level, achieve their goals, and improve overall satisfaction with their competition process and performance.

Effects of the Elevation Training Mask® 2.0 on dyspnea and respiratory muscle mechanics, electromyography, and fatigue during exhaustive cycling in healthy humans

OBJECTIVES

Examine the effects of the Elevation Training Mask® 2.0 (ETM) on dyspnea, and respiratory muscle function and fatigue during exercise.

DESIGN

Randomized crossover.

METHODS

10 healthy participants completed 2 time-to-exhaustion (TTE) cycling tests while wearing the ETM or under a sham control condition. During the sham, participants were told they were breathing air equivalent to "9000 ft" (matched to the selected resistance valves on the ETM according to the manufacturer), but they were breathing room air. Dyspnea and leg discomfort were assessed using the modified 0-10 category-ratio Borg scale. Qualitative dyspnea descriptors at peak exercise were selected from a list of 15. Crural diaphragmatic electromyography (EMG_di) and transdiaphragmatic pressure (P_di) were measured via a multipair esophageal electrode balloon catheter. Participants performed maximal respiratory maneuvers before and after exercise to estimate the degree of respiratory muscle fatigue.

RESULTS

Exercise with the ETM resulted in a significant decrease in TTE (p = 0.015), as well as increased dyspnea at baseline (p = 0.032) and during the highest equivalent submaximal exercise time (p = 0.0001). The increase in dyspnea with the ETM was significantly correlated with the decrease in exercise time (r = 0.73, p = 0.020). EMG_di and P_di were significantly increased with the ETM at all time points (all p < 0.05). There was a significant increase in the selection frequency of "my breath does not go in all the way" at peak exercise with the ETM (p = 0.02). The ETM did not induce respiratory muscle fatigue.

CONCLUSIONS

Exercising with the ETM appears to decrease exercise performance, in part, by increasing the sensation of dyspnea.

Sex-Specific Effects of Respiratory Muscle Endurance Training on Cycling Time Trial Performance in Normoxia and Hypoxia

Objectives: We tested the hypotheses that respiratory muscle endurance training (RMET) improves endurance cycling performance differently in women and men and more so in hypoxia than in normoxia. Design: A prospective pre-post cross-over study with two testing conditions. Methods: Healthy and active women (seven, 24 ± 4 years, mean ± standard deviation [SD]) and men (seven, 27 ± 5 years) performed incremental cycling to determine maximum oxygen consumption (VO_2peak) and power output (W_peak) and on different days two 10-km cycling time trials (TTs) in normoxia and normobaric hypoxia (FiO₂, 0.135, ~3,500 m equivalent), in a balanced randomized order. Next they performed supervised RMET in normoxia (4 weeks, 5 days/week, 30 min/day eucapnic hyperpnea at ~60% predicted maximum voluntary ventilation) followed by identical post-tests. During TTs, heart rate, ear oximetry reading, and W_peak were recorded. Results: The VO_2peak and W_peak values were unchanged after RMET. The TT was improved by 7 ± 6% (p < 0.001) in normoxia and 16 ± 6% (p < 0.001) in hypoxia. The difference between normoxic and hypoxic TT was smaller after RMET as compared with that before RMET (14% vs. 21%, respectively, p < 0.001). All effects were greater in women (p < 0.001). The RMET did not change the heart rate or ear oximetry reading during TTs. Conclusion: We found a greater effect of RMET on cycling TT performance in women than in men, an effect more pronounced in hypoxia. These findings are congruent with the contention of a more pronounced performance-limiting role of the respiratory system during endurance exercise in hypoxia compared with normoxia and more so in women whose respiratory system is undersized compared with that of men.

Effects of respiratory muscle training in soccer players: a systematic review with a meta-analysis

Respiratory muscle training can improve strength and reduce respiratory muscle fatigue during high-intensity exercise. Little is known about the existing evidence in soccer players. A systematic review with a meta-analysis was performed to analyse the existing evidence on the effects of respiratory muscle training in soccer players. Two independent researchers reviewed 17 databases until July 2019. Inclusion criteria were controlled clinical trials (randomised or not), soccer players (professional or recreational), females and/or males, and respiratory muscle training compared with simulated or regular training groups. The methodological quality and quality of evidence were evaluated with the Cochrane Collaboration Tool and GRADE score, respectively. Statistical analysis was performed using the integral meta-analysis 3.3.070. Nine studies met the eligibility criteria. The meta-analysis was performed for eight variables related to respiratory muscle function, lung function and sports performance. Respiratory muscle training provided a significant improvement compared with simulated or regular training in maximal inspiratory buccal pressure (6 studies, SDM = 0.89; 95 % CI = 0.42, 1.35) and maximum consumption of oxygen (3 studies, SDM = 0.92; 95 % CI = 0.24; 1.61). No significant improvements were observed for other variables. The quality of the evidence was rated as low or very low.

Effects of respiratory training on pulmonary function, bad mood, and quality of life in patients with COVID-19: A protocol for systematic review and meta-analysis

BACKGROUND

At present, whether respiratory training can improve the lung function, quality of life, and mental health of patients with Coronavirus Disease 2019 (COVID-19) is still controversial. Therefore, in order to provide new evidence-based medicine for clinical treatment, we conducted a systematic review and meta-analysis to evaluate the effects of respiratory training in improving lung function, quality of life, and mental health of patients with COVID-19.

METHODS

Relevant publications were searched from clinical trials. Computer was used to retrieve Cochrane Central Register of Controlled Trials Repositories, PubMed, Embase, and Web of Science databases. The retrieval time limit was from the establishment of the database to April 2021. Two researchers independently carried out data extraction and literature quality evaluation on the quality and meta-analysis of the included literature was performed with Revman 5.3 software.

RESULTS

The results of this meta-analysis will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This study will provide reliable evidence-based evidence on the effects of breathing training on lung function, bad mood, and quality of life in patients with COVID-19.

ETHICS AND DISSEMINATION

Ethical approval was not required for this study. The systematic review will be published in a peer-reviewed journal, presented at conferences, and shared on social media platforms.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/ZQTGY.

Effects of physical therapy on lung function in children with asthma: a systematic review and meta-analysis

BACKGROUND

Asthma is a common chronic respiratory disease in children. In addition to medications, physical therapy is considered as a treatment strategy for asthma. We conducted this study to investigate the effects of physical therapy on lung function in children with asthma.

METHODS

Three databases were searched. We conducted the meta-analysis for the forced expiratory volume in the first second in percent predicted values [FEV1(%pred)], the forced vital capacity in percent predicted values [FVC(%pred)], and the peak expiratory flow in percent predicted values [PEF(%pred)] by using a random effect model.

RESULTS

Of the 6474 identified studies, 18 studies (16 in physical training, 2 in breathing exercise or inspiratory muscle training) were included in the systematic review and 11 studies (all in physical training) were included in the meta-analysis. The meta-analysis showed a significantly improved FVC(%pred) in the experimental group.

CONCLUSIONS

Physical training improved FVC(%pred) significantly in children with asthma. Further study is needed, especially on the effects of breathing exercise and inspiratory muscle training in children with asthma.

IMPACT

Our study reviewed the physical therapies for children with asthma and clarified whether and how these therapies affect them. Our study found that physical training improved the forced vital capacity in percent predicted values [FVC(%pred)] significantly in asthmatic children. Our study provided evidence that physical training could improve lung function in children with asthma, which is not identical to the Global Initiative for Asthma (GINA) guidelines.

The Effect of Inspiratory Muscle Warm-Up on VO2 Kinetics during Submaximal Rowing

The aim of the study was to investigate the effect of an inspiratory muscle warm-up on the VO₂ kinetics during submaximal intensity ergometer rowing. Ten competitive male rowers (age 23.1 ± 3.8 years; height 188.1 ± 6.3 cm; body mass 85.6 ± 6.6 kg) took part in this investigation. A submaximal constant intensity (90% P_VO2max) rowing test to volitional exhaustion was carried out twice with the standard rowing warm-up (Test 1) and with the standard rowing warm-up with additional specific inspiratory muscle warm-up of two sets of 30 repetitions at 40% maximal inspiratory pressure (Test 2). We found a significant correlation between time constant (τ₁) and the VO₂ value at 400 s in Test 1 (r = 0.78; p < 0.05); however, no correlation was found between those parameters in Test 2. In addition, we found a positive association between VO_2max from the incremental rowing test and τ₁ from Test 1 (r = 0.71; p < 0.05), whereas VO₂ did not correlate with τ₁ from Test 2. Adding inspiratory muscle warm-up of 40% maximal inspiratory pressure to regular rowing warm-up had no significant effect on oxygen consumption kinetics during submaximal rowing tests.

Respiratory Muscle Strength and Ventilatory Function Outcome: Differences Between Trained Athletes and Healthy Untrained Persons

It is known that the maximum mouth inspiratory pressure (MIP) and expiratory pressure (MEP) vary with age, weight, height, and skeletal muscle mass. However, the influence of physical training on ventilatory function outcomes is an area of limited understanding. The aim of this study was to investigate the respiratory muscle strength and its relation to spirometry variables in untrained healthy persons versus trained athletes. MIP and MEP were assessed in 22 power athletes and 28 endurance athletes, and in 24 age- and sex-matched normal healthy subjects (control group). The measurement was done with a mouth pressure meter. We found that respiratory muscle strength and ventilatory function in endurance athletes were outstandingly superior to that in power athletes; the latter's muscle strength was better than that of healthy untrained controls. Both MIP and MEP significantly correlated with the maximum voluntary ventilation (MVV) in both power athletes and controls, but not so in endurance athletes. The corollary is that the intensive endurance training could result in the improvement of respiratory muscle strength, meeting the maximum upper limit of functional reserve of respiratory muscles and the corresponding ventilation. On the other hand, targeted training of respiratory muscle strength may be an effective strategy to increase ventilatory function in power athletes, particularly those having a low maximum inspiratory and expiratory pressure, and in less physically fit healthy persons.

Chronic Effects of a Training Program Using a Nasal Inspiratory Restriction Device on Elite Cyclists

This study compared the response of a 9-week cycling training on ventilatory efficiency under two conditions: (i) Combined with respiratory muscle training (RMT) using a new nasal restriction device (FeelBreathe) (FB group) and (ii) without RMT (Control group). Eighteen healthy elite cyclists were randomly separated into the FB group (n = 10) or Control group (n = 8). Gas exchange was measured breath by breath to measure ventilatory efficiency during an incremental test on a cycloergometer before (Pre) and after (Post) the nine weeks of training. The FB group showed higher peak power (Δ (95%HDI) (0.82 W/kg (0.49, 1.17)), VO₂max (5.27 mL/kg/min (0.69, 10.83)) and VT₁ (29.3 W (1.8, 56.7)) compared to Control at Post_FINAL. The FB group showed lower values from Pre to Post_PRE in minute ventilation (VE) (−21.0 L/min (−29.7, −11.5)), Breathing frequency (BF) (−5.1 breaths/min (−9.4, −0.9)), carbon dioxide output (VCO₂) (−0.5 L/min (−0.7, −0.2)), respiratory equivalents for oxygen (EqO₂) (−0.8 L/min (−2.4, 0.8)), heart rate (HR) (−5.9 beats/min (−9.2, −2.5)), respiratory exchange ratio (RER) (−0.1 (−0.1, −0.0) and a higher value in inspiratory time (Tin) (0.05 s (0.00, 0.10)), expiratory time (Tex) (0.11 s (0.05, 0.17)) and end-tidal partial pressure of CO₂ (PETCO₂) (0.3 mmHg (0.1, 0.6)). In conclusion, RMT using FB seems to be a new and easy alternative ergogenic tool which can be used at the same time as day-to-day training for performance enhancement.

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.

Exercise Related Respiratory Problems in the Young-Is It Exercise-Induced Bronchoconstriction or Laryngeal Obstruction?

Complaints of breathlessness during heavy exercise is common in children and adolescents, and represent expressions of a subjective feeling that may be difficult to verify and to link with specific diagnoses through objective tests. Exercise-induced asthma and exercise-induced laryngeal obstruction are two common medical causes of breathing difficulities in children and adolescents that can be challenging to distinguish between, based only on the complaints presented by patients. However, by applying a systematic clinical approach that includes rational use of tests, both conditions can usually be diagnosed reliably. In this invited mini-review, we suggest an approach we find feasible in our everyday clinical work.

Differences in Respiratory Muscle Responses to Hyperpnea or Loaded Breathing in COPD

INTRODUCTION

We aimed to compare acute mechanical and metabolic responses of the diaphragm and rib cage inspiratory muscles during two different types of respiratory loading in patients with chronic obstructive pulmonary disease.

METHODS

In 16 patients (age, 65 ± 13 yr; 56% male; forced expiratory volume in the first second, 60 ± 6%pred; maximum inspiratory pressure, 82 ± 5%pred), assessments of respiratory muscle EMG, esophageal pressure (Pes) and gastric pressures, breathing pattern, and noninvasive assessments of systemic (V˙O2, cardiac output, oxygen delivery and extraction) and respiratory muscle hemodynamic and oxygenation responses (blood flow index, oxygen delivery index, deoxyhemoglobin concentration, and tissues oxygen saturation [StiO2]), were performed during hyperpnea and loaded breathing.

RESULTS

During hyperpnea, breathing frequency, minute ventilation, esophageal and diaphragm pressure-time product per minute, cardiac output, and V˙O2 were higher than during loaded breathing (P < 0.05). Average inspiratory Pes and transdiaphragmatic pressure per breath, scalene (SCA), sternocleidomastoid, and intercostal muscle activation were higher during loading breathing compared with hyperpnea (P < 0.05). Higher transdiaphragmatic pressure during loaded breathing compared with hyperpnea was mostly due to higher inspiratory Pes (P < 0.05). Diaphragm activation, inspiratory and expiratory gastric pressures, and rectus abdominis muscle activation did not differ between the two conditions (P > 0.05). SCA-blood flow index and oxygen delivery index were lower, and SCA-deoxyhemoglobin concentration was higher during loaded breathing compared with hyperpnea. Furthermore, SCA and intercostal muscle StiO2 were lower during loaded breathing compared with hyperpnea (P < 0.05).

CONCLUSION

Greater inspiratory muscle effort during loaded breathing evoked larger rib cage and neck muscle activation compared with hyperpnea. In addition, lower SCA and intercostal muscle StiO2 during loaded breathing compared with hyperpnea indicates a mismatch between inspiratory muscle oxygen delivery and utilization induced by the former condition.

Training Specificity of Inspiratory Muscle Training Methods: A Randomized Trial

Introduction

Inspiratory muscle training (IMT) protocols are typically performed using pressure threshold loading with inspirations initiated from residual volume (RV). We aimed to compare effects of three different IMT protocols on maximal inspiratory pressures (PImax) and maximal inspiratory flow (V̇Imax) at three different lung volumes. We hypothesized that threshold loading performed from functional residual capacity (FRC) or tapered flow resistive loading (initiated from RV) would improve inspiratory muscle function over a larger range of lung volumes in comparison with the standard protocol.

Methods

48 healthy volunteers (42% male, age: 48 ± 9 years, PImax: 110 ± 28%pred, [mean ± SD]) were randomly assigned to perform three daily IMT sessions of pressure threshold loading (either initiated from RV or from FRC) or tapered flow resistive loading (initiated from RV) for 4 weeks. Sessions consisted of 30 breaths against the highest tolerable load. Before and after the training period, PImax was measured at RV, FRC, and midway between FRC and total lung capacity (1/2 IC). V̇Imax was measured at the same lung volumes against a range of external threshold loads.

Results

While PImax increased significantly at RV and at FRC in the group performing the standard training protocol (pressure threshold loading from RV), it increased significantly at all lung volumes in the two other training groups (all p < 0.05). No significant changes in V̇Imax were observed in the group performing the standard protocol. Increases of V̇Imax were significantly larger at all lung volumes after tapered flow resistive loading, and at higher lung volumes (i.e., FRC and 1/2 IC) after pressure threshold loading from FRC in comparison with the standard protocol (all p < 0.05).

Conclusion

Only training with tapered flow resistive loading and pressure threshold loading from functional residual capacity resulted in consistent improvements in respiratory muscle function at higher lung volumes, whereas improvements after the standard protocol (pressure threshold loading from residual volume) were restricted to gains in PImax at lower lung volumes. Further research is warranted to investigate whether these results can be confirmed in larger samples of both healthy subjects and patients.

Acute Effects of Using Added Respiratory Dead Space Volume in a Cycling Sprint Interval Exercise Protocol: A Cross-Over Study

Background: The aim of the study was to compare acute physiological, biochemical, and perceptual responses during sprint interval exercise (SIE) with breathing through a device increasing added respiratory dead space volume (ARDS_V) and without the device. Methods: The study involved 11 healthy, physically active men (mean maximal oxygen uptake: 52.6 ± 8.2 mL∙kg¹∙min^-1). During four visits to a laboratory with a minimum interval of 72 h, they participated in (1) an incremental test on a cycle ergometer; (2) a familiarization session; (3) and (4) cross-over SIE sessions. SIE consisted of 6 × 10-s all-out bouts with 4-min active recovery. During one of the sessions the participants breathed through a 1200-mL ARDSv (SIE_ARDS). Results: The work performed was significantly higher by 4.4% during SIE_ARDS, with no differences in the fatigue index. The mean respiratory ventilation was significantly higher by 13.2%, and the mean oxygen uptake was higher by 31.3% during SIE_ARDS. Respiratory muscle strength did not change after the two SIE sessions. In SIE_ARDS, the mean pH turned out significantly lower (7.26 vs. 7.29), and the mean HCO₃^- concentration was higher by 7.6%. Average La^- and rating of perceived exertion (RPE) did not differ between the sessions. Conclusions: Using ARDS_V during SIE provokes respiratory acidosis, causes stronger acute physiological responses, and does not increase RPE.

No Evidence That Hyperpnea-Based Respiratory Muscle Training Affects Indexes of Cardiovascular Health in Young Healthy Adults

Introduction

The chronic effects of respiratory muscle training (RMT) on the cardiovascular system remain unclear. This investigation tested to which degree a single sessions of RMT with or without added vibration, which could enhance peripheral blood flow and vascular response, or a 4-week RMT program could result in changes in pulse wave velocity (PWV), blood pressure (systolic, SBP; diastolic, DBP) and other markers of cardiovascular health.

Methods

Sixteen young and healthy participants (8 m/8f) performed 15 min of either continuous normocapnic hyperpnea (RMET), sprint-interval-type hyperpnea (RMSIT) or a control session (quiet sitting). Sessions were performed once with and once without passive vibration of the lower limbs. To assess training-induced adaptations, thirty-four young and healthy participants (17 m/17f) were measured before and after 4 weeks (three weekly sessions) of RMET (n = 13, 30-min sessions of normocapnic hyperpnea), RMSIT [n = 11, 6 × 1 min (1 min break) normocapnic hyperpnea with added resistance] or placebo (n = 10).

Results

SBP was elevated from baseline at 5 min after each RMT session, but returned to baseline levels after 15 min, whereas DBP was unchanged from baseline following RMT. Carotid-femoral PWV (PWV_CF) was elevated at 5 and 15 min after RMT compared to baseline (main effect of time, P = 0.001), whereas no changes were seen for carotid-radial PWV (PWV_CR) or the PWV_CF/PWV_CR ratio. Vibration had no effects in any of the interventions. Following the 4-week training period, no differences from the placebo group were seen for SBP (P = 0.686), DBP (P = 0.233), PWV_CF (P = 0.844), PWV_CR (P = 0.815) or the PWV_CF/PWV_CR ratio (P = 0.389).

Discussion/Conclusion

Although 15 min of RMT sessions elicited transient increases in PWV_CF and SBP, no changes were detected following 4 weeks of either RMET or RMSIT. Adding passive vibration of the lower limbs during RMT sessions did not provide additional value to the session with regards to vascular responses.

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.

The interest of rehabilitation of respiratory disorders in athletes: Myth or reality?

BACKGROUND

Healthy trained athletes generally have an "overbuilt" respiratory system in order to face the huge ventilation and gas-exchange demand imposed by strenuous exercise. Athletes frequently complain of respiratory symptoms regardless of whether they have a diagnosed respiratory disease, therefore evoking a kind of respiratory limitation during exercise. Some respiratory pathologies athletes present are closely linked to exercise and include asthma, exercise-induced bronchoconstriction (EIB) or exercise-induced laryngeal obstruction. Management of asthma and EIB are mainly based on pharmacological treatments. However, many athletes still complain of respiratory symptoms despite optimal pharmacological treatments, which highlights the need for non-pharmacological approaches including breathing retraining, inspiratory muscle training and/or laryngeal exercise performed under the guidance of a physiotherapist in this specific population.

OBJECTIVES

With this literature overview, we aimed to report evidence supporting the interest of rehabilitation for athletes with respiratory disorders and discuss whether inspiratory muscle training programs can improve performance in healthy athletes.

METHODS

We searched MEDLINE and Cochrane databases for trials, reviews and meta-analyses assessing respiratory rehabilitation and muscle training programs in athletes by using the MesH terms "athletes", "asthma", "dyspnea", "rehabilitation" and "education" published from January 2010 to March 2020. The selection of articles was based on the author's expertise to elaborate this review of the literature.

RESULTS

Major findings suggest that breathing retraining may help asthmatic athletes better control their respiratory symptoms and that inspiratory muscle training may improve respiratory symptoms of exercise-induced laryngeal obstruction in athletes. Improvement of performance by respiratory muscle training still remains controversial.

CONCLUSIONS

Respiratory rehabilitation could be of interest in the specific population of athletes but should be further evaluated to improve the level of evidence of such strategies.

No Decrease in Blood Pressure After an Acute Bout of Intermittent Hyperpnea and Hypoxia in Prehypertensive Elderly

Prevalence of hypertension, subjective sleep complaints and snoring increases with age. Worse sleep and snoring, in turn, are independent risk factors to develop hypertension. Both respiratory muscle training (RMT) and intermittent hypoxia (IH) are suggested to have positive effects on these physiological and behavioral variables. This study therefore aimed to test the acute effects of a single bout of RMT, with and without IH, on resting blood pressure (BP) and sleep. Fourteen prehypertensive elderly performed a 60-min session of (a) intermittent voluntary normocapnic hyperpnea (HYP) alone, (b) HYP in combination with IH (HYP&IH) and (c) a sham intervention in randomized order. BP, hemodynamics, heart rate variability (HRV), cardiac baroreflex sensitivity (BRS) and pulse wave velocity (PWV) were assessed before and 15, 30 and 45 min after each intervention. Variables of sleep were assessed with actigraphy, pulse oximetry and with questionnaires during and after the night following each intervention. Neither HYP nor HYP&IH resulted in a decrease in BP. Repeated measures ANOVA revealed no significant interaction effect for systolic BP (p = 0.090), diastolic BP (p = 0.151), HRV parameters, BRS and PWV (all p > 0.095). Fragmentation index was lower after both HYP (−6.5 units) and HYP&IH (−8.4 units) compared to sham, p(ANOVA) = 0.046, although pairwise comparisons reveal no significant differences. There were no other significant effects for the remaining sleep variables. We conclude that one bout of intermittent hyperpnea, alone or in combination with IH, is not effective in lowering blood pressure or improving sleep in prehypertensive elderly.

Endurance and Resistance Respiratory Muscle Training and Aerobic Exercise Performance in Hypobaric Hypoxia

INTRODUCTION: Hypoxia-induced hyperventilation is an effect of acute altitude exposure, which may lead to respiratory muscle fatigue and secondary locomotor muscle fatigue. The purpose of this study was to determine if resistive and/or endurance respiratory muscle training (RRMT and ERMT, respectively) vs. placebo respiratory muscle training (PRMT) improve cycling performance at altitude.METHODS: There were 24 subjects who were assigned to PRMT (N 8), RRMT (N 8), or ERMT (N 8). Subjects cycled to exhaustion in a hypobaric chamber decompressed to 3657 m (12,000 ft) at an intensity of 55% sea level maximal oxygen consumption (Vo_2max) before and after respiratory muscle training (RMT). Additionally, subjects completed a Vo_2max, pulmonary function, and respiratory endurance test (RET) before and after RMT. All RMT protocols consisted of three 30-min training sessions per week for 4 wk.RESULTS: The RRMT group increased maximum inspiratory (P_Imax) and expiratory (P_Emax) mouth pressure after RMT (P_Imax: 117.7 11.6 vs. 162.6 20.0; P_Emax: 164.0 33.2 vs. 216.5 44.1 cmH₂O). The ERMT group increased RET after RMT (5.2 5.2 vs.18.6 16.9 min). RMT did not improve Vo_2max in any group. Both RRMT and ERMT groups increased cycling time to exhaustion (RRMT: 35.9 17.2 vs. 45.6 22.2 min and ERMT: 33.8 9.6 vs. 42.9 27.0 min).CONCLUSION: Despite different improvements in pulmonary function, 4 wk of RRMT and ERMT both improved cycle time to exhaustion at altitude.Wheelock CE, Hess HW, Johnson BD, Schlader ZJ, Clemency BM, St. James E, Hostler D. Endurance and resistance respiratory muscle training and aerobic exercise performance in hypobaric hypoxia. Aerosp Med Hum Perform. 2020; 91(10):776784.

Impacts of Respiratory Muscle Training on Respiratory Functions, Maximal Exercise Capacity, Functional Performance, and Quality of Life in School-Aged Children with Postoperative Congenital Diaphragmatic Hernia

Objectives

Congenital diaphragmatic hernia (CDH) is a birth defect affecting the respiratory functions, functional performance, and quality of life (QOL) in school-aged children. Rarely have studies been conducted to evaluate the impacts of respiratory muscle training on school-aged children with postoperative CDH. The current study was designed to evaluate the impacts of respiratory muscle training on respiratory function, maximal exercise capacity, functional performance, and QOL in these children.

Methods

This study is a randomized control study. 40 children with CDH (age: 9-11 years) were assigned randomly into two groups. The first group conducted an incentive spirometer exercise combined with inspiratory muscle training (study group, n = 20), whereas the second group conducted only incentive spirometer exercise (control group, n = 20), thrice weekly for twelve consecutive weeks. Respiratory functions, maximal exercise capacity, functional performance, and pediatric quality of life inventory (PedsQL) were assessed before and after the treatment program. Results. Regarding the posttreatment analysis, the study group showed significant improvements in all outcome measures (FVC%, p < 0.001; FEV1%, p = 0.002; VO₂max, p = 0.008; VE/VCO₂ slope, p = 0.002; 6-MWT, p < 0.001; and PedsQL, p < 0.001), whereas the control group did not show significant changes (p > 0.05).

Conclusion

Respiratory muscle training may improve respiratory functions, maximal exercise capacities, functional performance, and QOL in children with postoperative CDH. Clinical commendations have to be considered to include respiratory muscle training in pulmonary rehabilitation programs in children with a history of CDH.

Restoration of cough via spinal cord stimulation improves pulmonary function in tetraplegics

Background: Spinal cord injury (SCI) results in significant loss in pulmonary function secondary to respiratory muscle paralysis. Retention of secretions and atelectasis and, recurrent respiratory tract infections may also impact pulmonary function. Objective: To determine whether usage of lower thoracic spinal cord stimulation (SCS) to restore cough may improve spontaneous pulmonary function in individuals with chronic SCI. Design/Methods: 10 tetraplegics utilized SCS system on a regular daily basis. Spontaneous inspiratory capacity (IC), maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) were measured at baseline prior to usage of the device and repeated every 4-5 weeks over a 20-week period. Maximum airway pressure generation (P) during SCS (40 V, 50 Hz, 0.2 ms) at total lung capacity (TLC) with subject maximal expiratory effort, at the same timepoints were determined, as well. Results: Following daily use of SCS, mean IC improved from 1636 ± 229 to 1932 ± 239 ml (127 ± 8% of baseline values) after 20 weeks (P < 0.05). Mean MIP increased from 40 ± 7, to 50 ± 8 cmH2O (127 ± 6% of baseline values) after 20 weeks, respectively (P < 0.05). MEP also improved from 27 ± 3.7 to 33 ± 5 (127 ± 14% of baseline values) (NS). During SCS, P increased from baseline in all participants from mean 87 ± 8 cmH2O to 117 ± 14 cmH2O at weeks 20, during TLC with subject maximal expiratory effort, respectively (P < 0.05). Each subject stated that they experienced much greater ease in raising secretions with use of SCS. Conclusion: Our findings indicate that use of SCS not only improves expiratory muscle function to restore cough but also results in improvement inspiratory function, as well.

Respiratory Muscle Performance Screening for Infectious Disease Management Following COVID-19: A Highly Pressurized Situation

The 2019-2020 coronavirus pandemic elucidated how a single highly infectious virus can overburden health care systems of even highly economically developed nations. A leading contributor to these concerning outcomes is a lack of available intensive care unit (ICU) beds and mechanical ventilation support. Poorer health is associated with a higher risk for severe respiratory complications from the coronavirus. We hypothesize that impaired respiratory muscle performance is an underappreciated factor contributing to poor outcomes unfolding during the coronavirus pandemic. Although impaired respiratory muscle performance is considered to be rare, it is more frequently encountered in patients with poorer health, in particular obesity. However, measures of respiratory muscle performance are not routinely performed in clinical practice, including those with symptoms such as dyspnea. The purpose of this article is to discuss the potential role of respiratory muscle performance from the perspective of the coronavirus pandemic. We also provide a theoretical patient management model to screen for impaired respiratory muscle performance and intervention, if identified, with the goal of unburdening health care systems during future pandemic crises.

Pattern of respiratory muscle activity during exercise tests in children born prematurely

INTRODUCTION

Preterm children display only slightly lower exercise capacity than term children do during their development, despite their previous cardiopulmonary impairments. This raises doubts about the role of the respiratory muscles' influence on exercise capacity. This study aimed to compare respiratory muscle activity in preterm and term children using an exercise test.

METHODS

This cross-sectional study involved comparison of 35 term children and 39 matched preterm children aged 6-9 years, who were born prematurely with a birth weight <1500 g. An adapted treadmill incremental test was utilized and surface electromyography of the sternocleidomastoid (SCM), upper trapezius (UT), and rectus abdominis (RA) muscles was performed. The root mean square was calculated every minute and compared between and within groups. A Monte Carlo simulation was also applied, and the area under the curve was calculated to evaluate the differences between groups.

RESULTS

During the entire exercise, the SCM muscle activity was higher in preterm children with a larger area under the curve than in the term children. There was no difference in the RA and UT muscle activity between groups throughout the test.

CONCLUSION

The results suggest a greater contribution of the SCM muscle sin preterm children's performance than in term children's performance during high-intensity exercises.

TRIAL REGISTRATION

Brazilian Clinical Trial Registry (ReBec) - RBR-89hr2h.

The effect of an airflow restriction mask (ARM) on metabolic, ventilatory, and electromyographic responses to continuous cycling exercise

This study analyzed the physiological adjustments caused by the use of the Elevation training mask® (2.0), an airflow restriction mask (ARM) during continuous exercise. Eighteen physically active participants (12 men and 6 women) were randomized to two protocols: continuous exercise with mask (CE-ARM) and continuous exercise without mask (CE). Exercise consisted of cycling for 20 minutes at 60% of maximum power. Metabolic variables, lactate, and gas concentration were obtained from arterialized blood samples at pre and post exercise. Continuous expired gases and myoelectric activity of the quadriceps were performed at rest and during the test. We observed no reduction in oxygen saturation in CE-ARM, leading to lower pH, higher carbon dioxide, and greater hematocrit (all p <0.05). The expired gas analysis shows that the CE-ARM condition presented higher oxygen uptake and expired carbon dioxide concentrations (p <0.05). The CE-ARM condition also presented lower ventilatory volume, ventilatory frequency, and expired oxygen pressure (p <0.05). No changes in electromyography activity and lactate concentrations were identified. We conclude that using ARM does not induce hypoxia and represents an additional challenge for the control of acid-base balance, and we suggest the use of ARM as being suitable for respiratory muscle training.

Influence of a Six-Week Swimming Training with Added Respiratory Dead Space on Respiratory Muscle Strength and Pulmonary Function in Recreational Swimmers

The avoidance of respiratory muscle fatigue and its repercussions may play an important role in swimmers' health and physical performance. Thus, the aim of this study was to investigate whether a six-week moderate-intensity swimming intervention with added respiratory dead space (ARDS) resulted in any differences in respiratory muscle variables and pulmonary function in recreational swimmers. A sample of 22 individuals (recreational swimmers) were divided into an experimental (E) and a control (C) group, observed for maximal oxygen uptake (VO2max). The intervention involved 50 min of front crawl swimming performed at 60% VO2max twice weekly for six weeks. Added respiratory dead space was induced via tube breathing (1000 mL) in group E during each intervention session. Respiratory muscle strength variables and pulmonary and respiratory variables were measured before and after the intervention. The training did not increase the inspiratory or expiratory muscle strength or improve spirometric parameters in any group. Only in group E, maximal tidal volume increased by 6.3% (p = 0.01). The ARDS volume of 1000 mL with the diameter of 2.5 cm applied in moderate-intensity swimming training constituted too weak a stimulus to develop respiratory muscles and lung function measured in the spirometry test.

The Effect of Vitamin D3 Supplementation on Physical Capacity among Active College-Aged Males

Vitamin D₃ supplementation can affect strength and power; however, the effect on both aerobic and anaerobic performance remains unclear. Here, we investigate the effects of eight weeks of a high dose of vitamin D₃ supplementation and its impact on circulating 25-hydroxyvitamin D (25-OH-D₃) concentrations and selected indicators of physical capacity. Subjects (n = 28, age 21.1 ± 1.6) were divided into two groups: supplemented (SUP), which was given 6000 IU of vitamin D₃ daily for eight weeks; and placebo group (PLA). Serum 25-OH-D₃ concentrations were determined in pre- and post-intervention. Aerobic (V.O_2max test) and anaerobic (Wingate Anaerobic Test) capacity were determined before and after the supplementation. The mean baseline concentration of 25-OH-D₃ was recognized as deficient (20 ng/mL) and significantly increased over time in the supplemented group (p < 0.01, η² = 0.86), whilst it remained unchanged in the placebo group. Moreover, the supplementation caused a significant improvement in maximal aerobic (p < 0.05, η² = 0.27) and anaerobic power (p < 0.01, η² = 0.51) whereas no changes were observed in PLA group. The V.O_2max differences were also significant in the supplemented group (p < 0.05). In summary, the changes in aerobic and anaerobic capacity observed in this study were associated with a serum concentration of 25-OH-D₃. Our data imply that vitamin D₃ supplementation with a dose of 6000 IU daily for eight weeks is sufficient to improve physical capacity and vitamin D₃ status.

Inspiratory Muscle Training in Intermittent Sports Modalities: A Systematic Review

The fatigue of the respiratory muscles causes the so-called metabolic reflex or metaboreflex, resulting in vasoconstriction of the blood vessels in the peripheral muscles, which leads to a decrease in respiratory performance. Training the respiratory muscles is a possible solution to avoid this type of impairment in intermittent sports. The objective of this systematic review was to evaluate the results obtained with inspiratory muscle training (IMT) in intermittent sports modalities, intending to determine whether its implementation would be adequate and useful in intermittent sports. A search in the Web of Science (WOS) and Scopus databases was conducted, following the Preferred Reporting Elements for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The methodological quality of the articles was assessed using the PEDro (Physiotherapy Evidence Database) scale. In conclusion, the introduction of specific devices of IMT seems to be a suitable method to improve performance in intermittent sports, mainly due to a reduction of the metaboreflex, fatigue sensation, and dyspnea. The ideal protocol would consist of a combination of acute and chronic treatment, and, even if IMT is done daily, the duration will not exceed one hour per week.