Weeks Of Respiratory Muscle Training Research Articles

Incremental Load Respiratory Muscle Training Improves Respiratory Muscle Strength and Pulmonary Function in Children with Bronchiectasis.

Participants underwent respiratory muscle training for 24 weeks. The main results were changes in respiratory muscle strength and pulmonary function indices (forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, peak expiratory flow rate (PEF), forced expiratory flow 25-75% (FEF25-75%), and maximal midexpiratory flow 75/25 (MMEF75/25)) before, 12 weeks after, and 24 weeks after the intervention. The secondary outcomes were changes in the exercise load and work rate, exercise work, Leicester Cough Questionnaire (LCQ) scale, and Fatigue Severity Scale (FSS). Compared with before the intervention, after 24 weeks of respiratory muscle training, the maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were significantly enhanced (P < 0.05), while FVC, FEV1, and PEF were significantly increased (P < 0.01). FEF25-75 and MMEF75/25 values showed significant improvement compared to those before training (P < 0.05). The exercise loading, work, and exercise work rate of expiratory muscle training were significantly improved compared to those before intervention (P < 0.05). The LCQ score increased significantly (P < 0.001), and the FSS score decreased significantly (P < 0.001). Incremental load respiratory muscle training effectively improved children's lung function over the long term, improved the strength of their inspiratory and expiratory muscles, and improved their quality of life.

Impact of Respiratory Muscle Training on Exercise Tolerance in Hypobaric Hypoxia

Hypoxia and certain chronic diseases can intensify the work of breathing, potentially impacting the muscle hyperemic response during exercise and overall exercise performance. Respiratory muscle training (RMT) has been observed to decrease perceived effort under hypoxic conditions; however, it remains unclear if RMT boosts exercise performance in acute hypoxia. We investigated whether 4 weeks of RMT could enhance maximal and submaximal exercise performance in hypoxia (PB=425 mmHg, ~4876 m). Seven adult males underwent a 250 kJ submaximal (RPE 15-17) cycling trial in hypoxia, followed by an incremental test to maximal exertion. After 4 weeks of RMT under normoxic conditions, these tests were repeated in hypoxia. Although six of the participants displayed improvements in submaximal exercise performance, these numerical differences failed to reach statistical significance. However, RMT did raise VO2max peak power (Pre-RMT: 242.62 ± 35, Post-RMT: 251.85 ± 38 W, p=0.04). Moreover, even with an increased HR during the submaximal exercise trial after RMT (Pre-RMT:154.14 ± 16, Post-RMT: 160.86 ± 12, p&lt;0.05), the RPE showed no significant difference during the test (Pre-RMT: 17.43 ± 0.79, Post-RMT: 17.43 ± 0.53, P&gt;0.05). Despite this, no substantial increase in hypoxic submaximal exercise performance was observed, likely due to the small sample size. These findings suggest RMT might increase hypoxic exercise tolerance by reducing perceived exertion for a given HR. This work was supported by funding from the United States Special Operations Command (USSOCOM) and the National Institutes of Health (2L30HL134123-03). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

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 ∆SmO2-m. vastus lateralis. ITL training induced higher V˙O2-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.

Effect of eight weeks respiratory muscle training on respiratory capacity, functional capacity and quality of life on subjects with mild to moderate relapsing-remitting multiple sclerosis: A single-blinded randomized controlled trial

BackgroundMultiple Sclerosis (MS) is a chronic inflammatory disease of the nervous system leading to muscle weakness, including the respiratory muscles that cause pulmonary complications, impair functional capacity, increased fatigue, and as a result decreases the quality of life. AimThe purpose of the present study is to examine the influence of 8 weeks of respiratory muscle training (RMT) on pulmonary function and respiratory muscle strength in MS patients. MethodsThe present study was a single-blind, randomized controlled trial that was conducted on 36 (27 Female, 9 Male) relapsing-remitting MS patients who were definitively diagnosed by a neurologist and randomly were divided into intervention and control groups. Both groups were educated on lifestyle modification with an emphasis on regular physical activity. In addition, the intervention group was prescribed eight weeks of respiratory muscle training with a threshold resistance device, daily, twice a day for three sets of 15 repetitions per set. Maximal expiratory pressure (PImax), maximal expiratory pressure (PEmax), spirometric indices, functional tests (six-minute walk test, timed up and go test), fatigue questionnaire, and questionnaire of quality of life were assessed before and after trials. ResultsA total of 36 patients (75% female; mean age 38.00(8.86) years; BMI 26.56(2.64) kg/m2) were included in the study. The strength of inspiratory and expiratory muscles, respiratory function, fatigue, and quality of life were significantly improved in the intervention group (p<0.005). In addition, there was a significant improvement in the rate of fatigue and quality of life in all their dimensions (p<0.005). Only in the six-minute walk test, no significant improvement was seen in the intervention group compared to the control group (p = 0.262). ConclusionFindings could help therapists to provide MS patients with more effective respiratory muscle training protocols to maximize the benefits of rehabilitation.

Effects of respiratory muscle training on respiratory efficiency and health-related quality of life in sedentary women with fibromyalgia: a randomised controlled trial

Fibromyalgia syndrome (FM) is a complex disease that is mainly characterised by chronic pain, fatigue, and sleep disturbances and may be precipitated or worsened by many stressors. The aim of this study was to examine the effects of respiratory muscle training (RMT) on respiratory efficiency and health-related quality of life (HRQoL) in women with FM. A total of 30 women with FM were included in the intention to treat analyses: 15 were assigned to the RMT group and 15 to the control group. The intervention consisted of 12 weeks of RMT. The primary outcome was the change in pulmonary function assessed by global body plethysmography at 12 weeks compared with baseline. Secondary outcomes included changes of scores in HRQoL assessed by the Short Form 36 Health Survey-Portuguese version. The maximal inspiratory pressure (MIP) improved by 17.5% (p-value = .033), maximal expiratory pressure (MEP) improved 21.6% (p-value = 0.045) and maximum occlusion pressure (P0.1 max) increased 27.7% (p-value = 0.007). HRQoL improved in the dimensions of physical function, physical role, bodily pain and vitality (p-value <0.05). RMT results in a significant improvement of respiratory efficiency and HRQoL after 12 weeks. RMT could be an effective therapy to enhance respiratory function and quality of life in women with FM.

The Effects Of Respiratory Muscle Training On Lung Function And Step Index Of College Students

PURPOSE: To observe the effects of short respiratory muscle training on lung function and step index of college students. METHODS: Fifteen students were recruited from Beijing Sport University, including 9 males (n = 9, age: 22.9 ± 1.14y, height: 174 ± 4.54 cm, weight: 70.1 ± 6.33 kg, BMI: 23.3 ± 1.46 kg/m2) and 6 females (n = 6, age: 22.4 ± 1.18y, height: 164 ± 2.1 cm, weight: 56 ± 7.03 kg, BMI: 20.2 ± 1.34 kg/m2). Respiratory muscle training consisted of 10 respiratory breaths per set using Lung Fitness equipment for 4 weeks (6 sets.d-1, three sets in the morning and evening respectively; 7 d.wk-1). The exhalation and inhalation resistance load are second and third gear according to the Lung Fitness equipment respectively. At baseline and after 4 weeks, lung function, heart rate, step index, RPE and RPB were evaluated. Paired t-tests were used to compare pre- and post-variables. RESULTS: 1. Forced vital capacity (3.47 ± 0.85 L) and forced expiratory volume in 1 second (3.27 ± 0.74 L) were significantly increased (P < 0.05). 2. RPE (13.53 ± 1.84) was significantly decreased after completion of step test (P < 0.05). 3. The step index (54.20 ± 9.22) was significantly increased (P < 0.05). CONCLUSIONS: Four weeks of respiratory muscle training alone can significantly improve the cardiopulmonary function of college students.

The Effect of Respiratory Muscle Training on Aerobic Power and Respiratory Parameters in Swimmers

Aim: The purpose of this study was to investigate the effect of 6 weeks respiratory muscle training on aerobic power (VO 2 max) and respiratory parameters in swimmers. Material and Methods: A total of 20 male swimmers between 18 and 23 years of age were included in the study as volunteers and randomly divided into two groups as control (n: 10) and control (n: 10) groups. Respiratory muscle training was applied to the experimental group 5 days a week for 6 weeks. Respiratory muscle training device (POWER®breathe, UK) and maximal inspiratory pressure (MIP) value of 30% of the respiratory muscle training 30 times twice a day was built. Body mass index, VO 2 max, vital capacity (VC), forced vital capacity (FVC), forced expiratory volume (FEV1) and forced expiratory rate (FEV1/FVC) were measured before and after training. Respiratory parameters were measured by spirometry. VO 2 max measurements were measured by cardiopulmonary exercise test on bicycle ergometer. Respiratory muscle strength was used to determine the respiratory pressure gauge. The data were analyzed in SPSS 22.0 program. Independent Samples T Test was used to assess the significance between the experimental and control groups. Paired Samples T Test was applied for intra-group comparisons. Results: As a result of the statistical analysis, there was a significant difference in the respiratory parameters of the experimental group (p<0.05). Aerobic power values were not significant (p>0.05). In the comparison between groups, there was a significant difference in the values of the respiratory parameters in favor of the experimental group. Conclusion: As a result, it can be said that 6 weeks of respiratory muscle training affects the respiratory parameters positively in swimmers. It is thought that regular respiratory muscle training improves respiratory parameters.

Respiratory muscle training in athletes with cervical spinal cord injury: effects on cardiopulmonary function and exercise capacity.

The effect of combined inspiratory and expiratory muscle training on resting and reflexive cardiac function, as well as exercise capacity, in individuals with cervical spinal cord injury (SCI) is presently unknown. Six weeks of combined inspiratory and expiratory muscle training enhances both inspiratory and expiratory muscle strength in highly-trained athletes with cervical SCI with no significant effect on lung function. There was a significant decrease in left-ventricular filling and stroke volume at rest in response to 45° head-up tilt, which is irreversible by respiratory muscle training. Combined inspiratory and expiratory muscle training increased peak aerobic work rate and reduced end-expiratory lung volumes during exercise, which may have implications for left-ventricular filling during exercise. To investigate the pulmonary, cardiovascular and exercise responses to combined inspiratory and expiratory respiratory muscle training (RMT) in athletes with tetraplegia, six wheelchair rugby athletes (five males and one female, aged 33±5years) completed 6weeks of pressure threshold RMT, 2 sessionsday-1 on 5daysweek-1 . Resting pulmonary and cardiac function, exercise capacity, exercising lung volumes and field-based exercise performance were assessed at pre-RMT, post-RMT and after a 6-week no RMT period. RMT enhanced maximal inspiratory (pre- vs. post-RMT: -76±15 to -106±23cmH2 O, P=0.002) and expiratory (59±26 to 73±32cmH2 O, P=0.007) mouth pressures, as well as peak expiratory flow (6.74±1.51vs. 7.32±1.60L/s, P<0.04). Compared to pre-RMT, peak work rate was higher at post-RMT (60±23 to 68±22W, P=0.003), whereas exercising end-expiratory lung volumes were reduced (P<0.017). Peak oxygen uptake increased in all athletes at post-RMT (1.24±0.40vs. 1.40±0.50lmin-1 , P=0.12). After 6weeks of no RMT all indices returned towards baseline, with peak work rate (P=0.037), peak oxygen uptake (P=0.041) and end-expiratory lung volume (P<0.034) being significantly lower at follow-up than at post-RMT. There was a significant decrease in left-ventricular end-diastolic volume and stroke volume in response to 45° head-up tilt (P=0.030 and 0.021, respectively); however, all cardiac indices in both supine and tilted positions were unchanged by RMT. Our findings demonstrate the efficacy of RMT with respect to enhancing respiratory muscle strength, lowering exercising lung volumes and increasing exercise capacity. Although the precise mechanisms by which RMT may enhance exercise capacity remain unclear, our data suggest that it is probably not the result of a direct cardiac adaptation associated with RMT.

Effect of high- and low-resistance inspiratory muscle training on physiological response to exercise in cross-country skiers.

The aim of the study was to evaluate the effect of different kinds of respiratory muscle training (RMT) on work capacity and selected spirometric indices in trained male cross-country skiers. The study involved 13 competitively trained, elite Polish male cross-country skiers. The subjects were randomly divided into two groups who completed 7 weeks of RMT: one with gradually increasing resistance (power RMT) and the other with constant resistance (endurance RMT). Both groups' training programs consisted of 30 inspiratory maneuvers performed twice a day, 6 days a week. The first week of RMT started with a low resistance (29 cmH2O). In the following weeks, resistance in the power RMT group was gradually increased, while in the endurance RMT group, inspiratory resistance was maintained at a constant level of 53 cm H2O (36±8% PImax). Maximal inspiratory pressure (PImax), peak inspiratory flow rate (PIF), and stress test indices were measured before and after RMT. The stress test was conducted on a ski ergometer, with a gradual increase in intensity in all-out effort. A significant increase in PImax, PIF, and exercise work capacity (test time, work output, and peak power) was noted in both groups. No significant changes were observed in the VO2max or the selected respiratory variables. During a short training period (up to 7 weeks), the use of gradual and constant inspiratory resistance during RMT improves exercise and spirometric parameters in a similar way. RMT did not have a considerable impact on breathing efficiency in maximal effort.

Efficacy of Bedside Respiratory Muscle Training in Patients With Stroke: A Randomized Controlled Trial.

Inspiratory and expiratory muscles are important for effective respiratory function. This study aimed to investigate the efficacy of bedside respiratory muscle training on pulmonary function and stroke-related disabilities in stroke rehabilitation. Patients with stroke (N = 40) in a rehabilitation unit were randomly assigned to either the intervention group (n1 = 20) or the control group (n2 = 20). Both groups participated in a conventional stroke rehabilitation program. During the study period, the intervention group received bedside respiratory muscle training twice a day for 3 wks. The respiratory muscle training consisted of (1) a breath stacking exercise, (2) inspiratory muscle training, and (3) expiratory muscle training. The primary outcomes were measures of pulmonary function: forced vital capacity, forced expiratory volume in 1 sec, and peak flow. Secondary outcomes were stroke-related disabilities assessed using the National Institutes of Health Stroke Scale, Modified Barthel Index, Berg Balance Scale, Fugl-Meyer Assessment, the Korean Mini-Mental State Examination, and pneumonia incidence. Pulmonary function was significantly improved in the intervention group after 3 wks of respiratory muscle training (P < 0.05). This improvement in pulmonary function was independent of the improvement in stroke-related disabilities. Three weeks of respiratory muscle training had significant effects on pulmonary function in stroke survivors. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Appreciate the respiratory function changes that occur in patients following a stroke; (2) Describe appropriate inspiratory and expiratory muscle training techniques to improve pulmonary function in patients following a stroke; (3) Enhance ability to implement inpatient; and (4) Determine appropriate respiratory training programs for patients following stroke. Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Respiratory Muscle Training Improves Chemoreflex Response, Heart Rate Variability, and Respiratory Mechanics in Rats With Heart Failure

BackgroundThe aim of the present report was to evaluate respiratory muscle training (RMT) effects on hemodynamic function, chemoreflex response, heart rate variability, and respiratory mechanics in rats with heart failure (HF rats). MethodsWistar rats were divided into 4 groups: sedentary–sham (Sed-Sham, n = 8), respiratory muscle trained–sham (RMT-Sham, n = 8), sedentary-HF (Sed-HF, n = 8) and respiratory muscle trained–HF (RMT-HF, n = 8). Animals were submitted to an RMT protocol performed 30 minutes per day, 5 days per week for 6 weeks, whereas the sedentary animals did not exercise. ResultsIn HF rats, RMT promoted the reduction of left ventricular end-diastolic pressure, right ventricular hypertrophy, and pulmonary edema. Moreover, RMT produced a reduction in pressure response during chemoreflex activation, sympathetic modulation, and sympathetic vagal balance in addition to an increase in parasympathetic modulation. Also after RMT, HF rats demonstrated a reduction in respiratory system resistance, tissue resistance, Newtonian resistance, respiratory system compliance, and quasistatic compliance. ConclusionsThese findings suggested that 6 weeks of RMT in HF rats promoted beneficial adaptations in hemodynamics, autonomic function, and respiratory mechanics and attenuated pressure response evoked by chemoreflex activation in HF rats.

Respiratory muscle training extends exercise tolerance without concomitant change to peak oxygen uptake: Physiological, performance and perceptual responses derived from the same incremental exercise test

There is conjecture over the efficacy of respiratory muscle training (RMT). The aim of this study was to establish whether or not exercise tolerance, physical performance and effort perceptions are influenced by RMT. Thirty-six healthy males (age 24 ± 4) agreed to participate (experimental group (EXP) n = 18, control (CON) n = 18). RMT was performed using an inspiratory pressure-threshold training device at either 55% (EXP) or 10% (CON) of maximal inspiratory effort. Measurements of spirometry and maximal static inspiratory mouth pressure were taken before and after 4 weeks of RMT in addition to an incremental test to volitional exhaustion for the determination of: (i) V˙O(2) peak; (ii) maximal velocity at volitional exhaustion (vV˙O(2) peak)); (iii) time to volitional exhaustion; and (iv) effort perceptions. There were no differences in spirometry, but mean maximal static inspiratory mouth pressure increased significantly in EXP (P < 0.01). V˙O(2) peak was unchanged following the 4-week intervention for both EXP and CON, although the proportion of EXP attaining the criteria for a V˙O(2) plateau significantly increased (P < 0.05). Both time to volitional exhaustion (P < 0.05) and vV˙O(2) peak were significantly improved for EXP (P < 0.05), while effort perceptions were reduced (P < 0.05). EXP tolerated higher running velocities during incremental exercise and demonstrated a significant flattening (plateau) of V˙O(2) after training. This suggests that RMT may promote an improved performance outcome vV˙O(2) peak probably as a result of blunted afferent sensations reducing the perceived discomfort of exercise at high ventilatory loads.

Concurrent respiratory resistance training and changes in respiratory muscle strength and sleep in an individual with spinal cord injury: case report

ContextQuality sleep possesses numerous benefits to normal nighttime and daytime functioning. High-level spinal cord injury (SCI) often impacts the respiratory muscles that can lead to poor respiratory function during sleep and negatively affect sleep quality. The impact of respiratory muscle training (RMT) on sleep quality, as assessed by overnight polysomnography (PSG), is yet to be determined among the spinal cord-injured population. This case report describes the effects of 10 weeks of RMT on the sleep quality of a 38-year-old male with cervical SCI.MethodsCase report.Findings/resultsThe subject completed overnight PSG, respiratory muscle strength assessment, and subjective sleepiness assessment before and after 10 weeks of RMT. The post-test results indicated improvements in sleep quality (e.g. fewer electroencephalographic (EEG) arousals during sleep) and daytime sleepiness scores following RMT.Conclusion/clinical relevanceRespiratory activity has been proven to impact EEG arousal activity during sleep. Arousals during sleep lead to a fragmented sleeping pattern and affect sleep quality and daytime function. Our subject presented with a typical sleep complaint of snoring and excessive sleepiness. The subject's pre-test PSG demonstrated a large number of arousals during sleep. It is important for all individuals complaining of problems during sleep or daytime problems associated with sleep (i.e. excessive daytime sleepiness) to seek medical attention and proper evaluation.

Respiratory muscle training and maximum aerobic power in hypoxia

In a recent paper, Keramidas et al. (2010) investigated the effects of respiratory muscle training (RMT) on endurance exercise performance in normoxia (N) and hypoxia (H; FIO2 = 0.12). Participants were randomly assigned either to RMT or control training group. Both groups performed regular (1 h/day, 5 days/week at 50% of peak power output) aerobic training on a cycle ergometer, while RMT group performed an additional specific training programme of respiratory muscles (isocapnic hyperpnoea) prior to the cycle ergometry. After 4 weeks of training, both groups enhanced maximum oxygen uptake _ VO2max in N, but only the RMT group improved _ VO2max (only specific, not absolute) significantly in H. The enhanced _ VO2max in H in the RMT group was accompanied by increased maximum ventilation _ VE , but at an identical peak power output, most likely resulting in an increased metabolic demand of the respiratory muscles. However, in this study, peak power output was calculated as the last workload completed of a ramp test (30 W/min). If this is the case, peak power output would be a supramaximal power, which both aerobic and anaerobic energy sources would contribute to, and thus cannot be defined as the maximum aerobic mechanical power, which corresponds to the lowest power requiring a _ VO2 equal to _ VO2max. Always, whether in N or in H, an increase in _ VO2max is accompanied by an increase in maximum mechanical power. In a similar paper, Esposito et al. (2010) assessed the effects of 8 weeks RMT (isocapnic hyperpnoea, 5 training sessions per week, 10–20 min each including warm up; the volume and the frequency of respiratory cycles were increased progressively, based on participants’ response to training work loads) on _ VO2max in N and H (FIO2 = 0.11). After 8 weeks of RMT, no changes in cardiorespiratory and metabolic variables were detected at maximal exercise in N. On the contrary, in H _ VE and alveolar ventilation _ VA at maximal exercise were significantly higher than in pre-training condition. Accordingly, alveolar O2 partial pressure (PAO2 ) after RMT significantly increased by *10%. Nevertheless, arterial PO2 and _ VO2max did not change with respect to pre-training condition. Thus, the authors provided evidence that RMT did not have any effect on _ VO2max, under either normoxic or hypoxic condition. They concluded that in H, the significant increase in _ VE and _ VA at maximum exercise after RMT lead to higher alveolar but not arterial PO2 values, revealing an increased A–a gradient. Thus, a possible role of increased ventilation–perfusion mismatch was suggested. According to multifactorial models of _ VO2max limitation (di Prampero 1985; di Prampero and Ferretti 1990), the O2 transfer from ambient air to mitochondria is set by a cascade of resistances in series, each resistance being overcome by a specific O2 partial pressure gradient. Four major resistances have been identified in the studies cited above (1) ventilatory (RV) between ambient and alveoli; (2) lung (RL) between alveoli and arterial blood; (3) circulatory (RQ) between arterial blood and muscle capillaries; (4) peripheral (Rp) between muscle capillaries and Communicated by Susan Ward.

Effect of respiratory muscle training on maximum aerobic power in normoxia and hypoxia

To assess the effects of respiratory muscle training (RMT) on maximum oxygen uptake (VO2max) in normoxia and hypoxia, 9 healthy males (age 24 +/- 4 years; stature 1.75 +/- 0.08 m; body mass 72 +/- 9 kg; mean +/- SD) performed on different days maximal incremental tests on a cycle ergometer in normoxia and normobaric hypoxia (FIO2=0.11), before and after 8 weeks of RMT (5 days/week). During each test, gas exchange variables were measured breath-by-breath by a metabolimeter. After RMT, no changes in cardiorespiratory and metabolic variables were detected at maximal exercise in normoxia. On the contrary, in hypoxia expired and alveolar ventilation (V(E(and V(A), respectively) at maximal exercise were significantly higher than pre-training condition (+12 and +13%, respectively; P < 0.05). Accordingly, alveolar O2 partial pressure (PAO2) after RMT significantly increased by approximately 10%. Nevertheless, arterial PO2 and VO2max did not change with respect to pre-training condition. In conclusion, RMT improved respiratory function but did not have any effect on VO2max, neither under normoxic nor hypoxic condition. In hypoxia, the significant increase in V(E) and V(A) at maximum exercise after training lead to higher alveolar but not arterial PO2 values, revealing an increased A-a gradient. This result, according to the theoretical models of VO2max limitation, seems to contradict the lack of VO2max increase in hypoxia, suggesting a possible role of increased ventilation-perfusion mismatch.

The Effect of Respiratory Muscle Training on Performance, Dyspnea, and Respiratory Muscle Fatigue in Intermittent Sprint Athletes

The respiratory system has traditionally not been considered a limiting factor in aerobic performance. However, little is known regarding the potential influence of respiratory muscle training (RMT) during short-term, high-intensity intermittent exercise. PURPOSE: To determine the effect of respiratory muscle training (RMT) on respiratory muscle strength (PImax), performance, dyspnea, and respiratory muscle fatigue (RMF) in intermittent sprint athletes. METHODS: Collegiate soccer athletes (N = 27; 20 male, 7 female) were randomly divided into either a RMT or control condition. The RMT group received 5 weeks of RMT using a commercially available training device (Powerlung Inc.), while the control group received no intervention. Both groups continued to train under the supervision of their coaches throughout the intervention. The Yo-Yo Intermittent Recovery Test (IRT), designed for evaluating intermittent-sprint fitness, was used to assess performance. Dyspnea was assessed during and immediately following the IRT. RMF was assessed 2 minutes and 10 minutes after completion of the IRT. RESULTS: Performance improved by (mean ± SD) 16.7% ± 17.2% in the RMT group (p ≤ .05), while a non-significant increase (5.2% ± 7.8%) was observed in the control group. The RMT group also demonstrated a significant increase in PImax (20.5% ± 15.4%), whereas the control group exhibited little change in this variable (1.5% ± 4.7%). No statistically significant changes in dyspnea or RMF were detected in either group following RMT. CONCLUSIONS: RESULTS from this study indicate that RMT improves performance and respiratory muscle strength in intermittent sprint athletes.

Variable effects of respiratory muscle training on cycle exercise performance in men and women

Respiratory muscle training (RMT) has been proposed as an effective means to increase the strength of the inspiratory muscles and improve exercise performance. The purpose of this study was to examine the effect of RMT on cycling time to exhaustion (TTE) and to determine any potential sex effect. We hypothesized that RMT would improve maximal inspiratory pressure (MIP) and TTE to a similar degree in men and women. Males (n = 7; mean (+/- SD) age, 22.1 +/- 1.5 y) and females (n = 8; mean (+/- SD) 24.5 +/- 4.9 y) performed an incremental cycle test to determine maximal oxygen consumption ((.)VO(2) (max)) (day 1), followed by a familiarization TTE (day 2) and baseline TTE (day 3) at 80% maximal work achieved during the ((.)VO(2) (max)) test. Subjects then completed 5 weeks of respiratory muscle training (RMT) (5 d/week, 2 sets of 30 inspirations against 50% MIP). Four training sessions per week were performed at home and the 5th was supervised, during which the threshold load was increased if necessary. Following RMT, subjects completed 2 TTE tests (days 4 and 5). MIP increased in each subject (37% +/- 18%, P < 0.05). There was no difference between men (pre = -100 +/- 20 vs. post = -140 +/- 29 cmH(2)O) and women (pre = -90 +/- 28 vs. post = -117 +/- 28 cmH(2)O). Baseline TTE (male = 301 +/- 122 s; female = 338 +/- 98 s) was shorter in comparison with the best of the 2 TTE-post tests (male = 353 +/- 68 s; female = 416 +/- 116 s; P < 0.01), but not when compared with days 4 or 5 (P > 0.05). RMT increases MIP and may improve exercise performance; however, improvements are variable with no differences between men and women.

Fixed Load Incremental Respiratory Muscle Training: A pilot study

Summary The purpose of this pilot study was to examine the use of a new incremental test of respiratory endurance (the ‘TIRE’) as a method of fixed load respiratory muscle training (RMT) in normal volunteers. Ten subjects completed ten weeks of RMT with training levels set at 80% of peak. Using the related t-test to analyse the data significant increases were seen in respiratory muscle strength (p We conclude that fixed load incremental RMT, set at a level consistent with systemic training regimes, increases the strength and endurance of respiratory muscles. Further controlled investigation in a larger population is required. This should include training level manipulation by the TIRE to obtain strength or endurance effect and formal assessment of the dyspnoea perception and systemic performance reported anecdotally during this study.