Inspiratory Muscle Training in Patients with Chronic Obstructive Pulmonary Disease: The State of the Evidence

Purpose: The purpose of the present review was to assess the quality of evidence in the literature regarding the specific benefits of inspiratory muscle training (IMT) with an emphasis on training intensity and the relationships between changes in inspiratory muscle function and other clinical outcome measures. Methods: Articles were found by searching CINAHL, PubMed, Medline via First Search, and ProQuest databases. Articles used in the review were randomized trials of IMT vs. sham IMT or no intervention, published in English in a peer-reviewed journal, included patients with chronic obstructive pulmonary disease (COPD), and specified the intensity of training. The quality of the studies was evaluated by 2 independent reviewers using the methodological rigor scale described by Medlicott and Harris as well as Sackett''s levels of evidence. Fifteen articles met the inclusion criteria and were used in this review. Results: Consistent improvements in maximal inspiratory pressures (ranging from −11 to −30 cm H₂O) and inspiratory muscle endurance were found. Improvements in dyspnea and health-related quality of life were also observed. Inspiratory muscle training may result in improved exercise tolerance as measured using walking tests. High-intensity IMT resulted in improved training efficiency with respect to inspiratory muscle strength, but evidence of the effect of high-intensity IMT on other clinical outcomes is lacking. Conclusion: Despite research spanning decades, there are numerous limitations in the literature regarding IMT. IMT appears to improve dyspnea, waking test distance, and health-related quality of life in individuals with COPD, but it is not clear whether this improvement is mediated through improved inspiratory muscle strength and endurance. This review discussed several considerations critical to the design of future trials.Key Words: inspiratory muscle training, COPD     

Effects of inspiratory muscle training in professional women football players: a randomized sham-controlled trial

This study was conducted to determine the effects of inspiratory muscle training (IMT) on respiratory and peripheral muscles oxygenation during a maximal exercise tolerance test and on repeated-sprint ability (RSA) performance in professional women football players. Eighteen athletes were randomly assigned to one of the following groups: SHAM (n = 8) or IMT (n = 10). After a maximal incremental exercise test, all participants performed (on a different day) a time-to-exhaustion (Tlim) test. Peripheral and respiratory muscles oxygenation by near-infrared spectroscopy, breath-by-breath ventilatory and metabolic variables, and blood lactate concentration were measured. The RSA test was performed on a grass field. After a 6 week intervention, all athletes were reevaluated. Both groups showed increases in inspiratory muscles strength, exercise tolerance and RSA performance, however only the IMT group presented lower deoxyhemoglobin and total hemoglobin blood concentrations on intercostal muscles concomitantly to an increased oxyhemoglobin and total hemoglobin blood concentrations on vastus lateralis muscle during Tlim. In conclusion, these results may indicate the potential role of IMT to attenuate inspiratory muscles metaboreflex and consequently improve oxygen and blood supply to limb muscles during high-intensity exercise, with a potential impact on inspiratory muscle strength, exercise tolerance and sprints performance in professional women football players.     

Training the inspiratory muscles improves running performance when carrying a 25 kg thoracic load in a backpack

Load carriage (LC) exercise in physically demanding occupations is typically characterised by periods of low-intensity steady-state exercise and short duration, high-intensity exercise while carrying an external mass in a backpack; this form of exercise is also known as LC exercise. This induces inspiratory muscle fatigue and reduces whole-body performance. Accordingly we investigated the effect of inspiratory muscle training (IMT, 50% maximal inspiratory muscle pressure (P_Imax) twice daily for six week) upon running time-trial performance with thoracic LC. Nineteen healthy males formed a pressure threshold IMT (n?=?10) or placebo control group (PLA; n?=?9) and performed 60?min LC exercise (6.5?km?h^–1) followed by a 2.4?km running time trial (LC_TT) either side of a double-blind six week intervention. Prior to the intervention, P_Imax was reduced relative to baseline, post-LC and post-LC_TT in both groups (pooled data: 13?±?7% and 16?±?8%, respectively, p?P_Imax increased +31% (p?TT (+18%, p?P_Imax at each time point was unchanged (13?±?11% and 17?±?9%, respectively, p?>?.05). In IMT only, heart rate and perceptual responses were reduced post-LC (p?p?相似文献   

Delayed Onset Muscle Soreness After Inspiratory Threshold Loading in Healthy Adults

Purpose: Skeletal muscle damage occurs following high-intensity or unaccustomed exercise; however, it is difficult to monitor damage to the respiratory muscles, particularly in humans. The aim of this study was to use clinical measures to investigate the presence of skeletal muscle damage in the inspiratory muscles. Methods: Ten healthy subjects underwent 60 minutes of voluntary inspiratory threshold loading (ITL) at 70% of maximal inspiratory pressure. Maximal inspiratory and expiratory mouth pressures, delayed onset muscle soreness on a visual analogue scale and plasma creatine kinase were measured prior to ITL, and at repeated time points after ITL (4, 24 and 48 hours post-ITL). Results: Delayed onset muscle soreness was present in all subjects 24 hours following ITL (intensity = 22 ± 6 mm; significantly higher than baseline p = 0.02). Muscle soreness was reported primarily in the anterior neck region, and was correlated to the amount of work done by the inspiratory muscles during ITL (r = 0.72, p = 0.02). However, no significant change was observed in maximal inspiratory or expiratory pressures or creatine kinase. Conclusions: These findings suggest that an intense bout of ITL results in muscle soreness primarily in the accessory muscles of inspiration, however, may be insufficient to cause significant muscle damage in healthy adults.Key Words: delayed onset muscle soreness, respiratory muscles, skeletal muscle damage     

力量训练方法和负荷结构的研究

力量训练的效果,取决于方法和负荷的有机统一,科学地控制力量训练,其根本就在于对力量训练方法的选择和负荷的优化。阐述了方法和负荷的优化组合及力量训练的科学性,指出力量训练是一种动态的控制系统,方法和负荷结构的结合,处在一种不断的调整和变化中,以不断地对人体的运动中枢和肌肉施以变化着的刺激去追求训练上的不断突破。     

Inspiratory Muscle Training in Patients with Heart Failure: A Systematic Review

Purpose

The purpose of this review was to assess the quality of evidence on inspiratory muscle training (IMT) in patients with heart failure and to provide an overview on subject selection, training protocols, and outcome achieved with IMT.

Methods

Literature search was first performed via the PubMed database, and additional references were identified from the Scopus citation index. Articles of the review type and of clinical trials published in English were included. Quality of the articles was assessed using Sackett''s levels of evidence and rigor of methodology was assessed using PEDro (Physiotherapy Evidence Database) criteria for randomized controlled trials and the Downs & Black tool for cohort studies.

Results

Twelve articles of clinical trials were included. Typical training protocols involved daily training with intensity greater than 30% of maximal inspiratory pressure (PImax), duration of 20 to 30 minutes (continuous or incremental) and using a pressure threshold muscle trainer. The effect sizes of PImax, walk test distance, and dyspnea were moderate to large across these studies. Effects on quality of life scores were inconsistent.

Conclusion

Inspiratory muscle training is beneficial for improving respiratory muscle strength, functional capacity, and dyspnea in patients with stable heart failure and respiratory muscle weakness.Key Words: inspiratory muscle training, heart failure, maximal inspiratory pressure     

Identifying the optimal resistive load for complex training in male rugby players

Alternating a resistance exercise with a plyometric exercise is referred to as "complex training". In this study, we examined the effect of various resistive loads on the biomechanics of performance of a fast stretch-shortening cycle activity to determine if an optimal resistive load exists for complex training. Twelve elite rugby players performed three drop jumps before and after three back squat resistive loads of 65%, 80%, and 93% of a single repetition maximum (1-RM) load. All drop jumps were performed on a specially constructed sledge and force platform apparatus. Flight time, ground contact time, peak ground reaction force, reactive strength index, and leg stiffness were the dependent variables. Repeated-measures analysis of variance found that all resistive loads reduced (P < 0.01) flight time, and that lifting at the 93% load resulted in an improvement (P < 0.05) in ground contact time and leg stiffness. From a training perspective, the results indicate that the heavy lifting will encourage the fast stretch-shortening cycle activity to be performed with a stiffer leg spring action, which in turn may benefit performance. However, it is unknown if these acute changes will produce any long-term adaptations to muscle function.     

Effects of inspiratory muscle training on time-trial performance in trained cyclists

We evaluated the effects of specific inspiratory muscle training on simulated time-trial performance in trained cyclists. Using a double-blind, placebo-controlled design, 16 male cyclists (VO 2max = 64 - 2 ml·kg -1 ·min -1 ; mean - sx ¥ ) were assigned at random to either an experimental (pressure-threshold inspiratory muscle training) or sham-training control (placebo) group. Pulmonary function, maximum dynamic inspiratory muscle function and the physiological and perceptual responses to maximal incremental cycling were assessed. Simulated time-trial performance (20 and 40 km) was quantified as the time to complete pre-set amounts of work. Pulmonary function was unchanged after the intervention, but dynamic inspiratory muscle function improved in the inspiratory muscle training group ( P h 0.05). After the intervention, the inspiratory muscle training group experienced a reduction in the perception of respiratory and peripheral effort (Borg CR10: 16 - 4% and 18 - 4% respectively; compared with placebo, P h 0.01) and completed the simulated 20 and 40 km time-trials faster than the placebo group [66 - 30 and 115 - 38 s (3.8 - 1.7% and 4.6 - 1.9%) faster respectively; P = 0.025 and 0.009]. These results support evidence that specific inspiratory muscle training attenuates the perceptual response to maximal incremental exercise. Furthermore, they provide evidence of performance enhancements in competitive cyclists after inspiratory muscle training.     

Effects of inspiratory muscle training on time-trial performance in trained cyclists

We evaluated the effects of specific inspiratory muscle training on simulated time-trial performance in trained cyclists. Using a double-blind, placebo-controlled design, 16 male cyclists (VO2max = 64 +/- 2 ml x kg(-1) x min(-1); mean +/- s(x)) were assigned at random to either an experimental (pressure-threshold inspiratory muscle training) or sham-training control (placebo) group. Pulmonary function, maximum dynamic inspiratory muscle function and the physiological and perceptual responses to maximal incremental cycling were assessed. Simulated time-trial performance (20 and 40 km) was quantified as the time to complete pre-set amounts of work. Pulmonary function was unchanged after the intervention, but dynamic inspiratory muscle function improved in the inspiratory muscle training group (P < or = 0.05). After the intervention, the inspiratory muscle training group experienced a reduction in the perception of respiratory and peripheral effort (Borg CR10: 16 +/- 4% and 18 +/- 4% respectively; compared with placebo, P < or = 0.01) and completed the simulated 20 and 40 km time-trials faster than the placebo group [66 +/- 30 and 115 +/- 38 s (3.8 +/- 1.7% and 4.6 +/- 1.9%) faster respectively; P = 0.025 and 0.009]. These results support evidence that specific inspiratory muscle training attenuates the perceptual response to maximal incremental exercise. Furthermore, they provide evidence of performance enhancements in competitive cyclists after inspiratory muscle training.     

Monitoring markers of muscle damage during a 3 week periodized drop-jump exercise programme

The aim of this study was to examine changes in indirect markers of muscle damage during 3 weeks of stretch-shortening exercise with a progressively increasing load and continued modulation of various key training variables. Eight healthy untrained men performed a drop-jump programme involving a progressive increase in load impact with respect to the number of jumps performed, drop (platform) height, squat depth amplitude, and addition of weights. Maximal concentric and isometric knee extensor strength were assessed immediately before and 10?min after each training session. Voluntary and 100 Hz-stimulation-evoked torque decreased acutely after each training session relative to pre-exercise values (P?相似文献   

Maximal oxygen uptake and work capacity after inspiratory muscle training: a controlled study

The effect of inspiratory muscle training for 10 min twice a day for 27.5 days was evaluated in 20 human subjects, of whom 10 formed a training group and 10 a sham training group. The maximal oxygen uptake (VO2 max), maximal ventilation, breathing frequency during maximal exercise and the distance run in 12 min on a track were determined in addition to resting peak expiratory flow, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1), with alveolar oxygen tension (pAO2) during maximal exercise being calculated. Inspiratory muscle training increased maximal inspiratory pressure from 93 (range 38-118) to 110 (65-165) mmHg in the training group (P less than 0.0005), but did not affect VO2 max, ventilation during maximal exercise, peak expiratory flow, FEV1 or FVC. However, breathing frequency during maximal exercise decreased slightly from 56 (44-87) to 53 (38-84) breaths min-1 (P less than 0.05) in the training group only; but the calculated pAO2 did not increase from the pre-training value of 126 (116-132) mmHg. The maximal distance run during 12 min increased similarly in the training and sham training groups by 8% (3-12%) and 6% (2-12%), respectively (P less than 0.01). The results of this study show that inspiratory muscle training resulting in a 32% (0-85%) increase in maximal inspiratory pressure does not change FEV1, FVC, peak expiratory flow, VO2 max or work capacity.     

论力量训练与变阻力练习思路的形成

力量训练是各专项运动训练必备的辅助性体能训练内容。对于阻力练习与肌肉力量之间关系的研究,已取得大量成果。区分增加肌肉粗壮的练习与增强肌力的练习的界限是重要的。每组练习的重复次数决定了各种训练程序的不同特性。为了发展最大力量,需要增加强度,而不是练习的数量。变阻力训练思路的形成基于固定阻力训练中两方面的局限性。作为力量训练中的最新进展,变阻力训练思路来自于对等动训练和等张训练的比较,证明等动训练程序显然优于等张训练程序,等动训练能恰当地给特定速度的运动提供调节阻力。本文还介绍了几种提高肌肉力量的常用重力训练方法。     

Inspiratory muscle training effects on oxygen saturation and performance in hypoxemic rowers: Effect of sex

ABSTRACT

Exercise-induced arterial hypoxemia (EIAH) has been consistently reported in elite endurance athletes. This study examined the effects of an inspiratory muscle training protocol (IMT) on resting pulmonary function, end-exercise arterial oxygen saturation and performance in hypoxemic rowers. Twenty male and sixteen female well-trained hypoxemic rowers were divided into four groups: IMT-male, control-male, IMT-female and control-female. The IMT groups, additionally to the regular training, performed IMT (30 min/day, 5 times/week, 6 weeks). Before and after training, groups underwent an incremental rowing test, a 2000-m time trial and a 5-min “all-out” race. IMT increased respiratory strength in the IMT-male (135 ± 31 vs. 180 ± 22 cmH₂O) and IMT-female (93 ± 19 vs. 142 ± 22 cmH₂O) (P < 0.05). The IMT-female group exhibited lower EIAH and improved rowing performance in the 2000-m time trial (487 ± 32 vs. 461 ± 34 sec) and in the 5-min “all-out” test (1,285 ± 28 vs. 1,310 ± 36m) (P < 0.05). IMT protocol improved performance in IMT-male only in the 5-min test (1,651 ± 31 vs. 1,746 ± 37m) (P < 0.05). IMT may be a useful tool for increasing respiratory strength and enhancing performance in hypoxemic rowers, especially for women.

Abbreviations: EIAH: Exercise-induced arterial hypoxemia; IMT: inspiratory muscle training protocol; PaO2: partial pressure of arterial oxygen; SaO2: arterial oxyhemoglobin saturation; VO2max: maximal oxygen consumption; [(A-a)DO2]: alveolar-to-arterial oxygen difference; VA/Q: ventilation-perfusion inequality/mismatching; PImax: maximal inspiratory pressure; BMI: body mass index; BSA: body surface area; FVC: vital capacity; FEV1: forced expiratory volume in 1 sec; VCin: vital capacity; MVV12: maximal voluntary ventilation in 12 sec     

The acute effects of bodyweight suspension exercise on muscle activation and muscular fatigue

This investigation examined effects of two exercise modes (barbell, BB; bodyweight suspension, BWS) on muscle activation, resistance load, and fatigue. During session one, nine resistance-trained males completed an elbow flexion one-repetition maximum (1RM). During sessions two and three, subjects completed standing biceps curls to fatigue at 70% 1RM utilizing a randomized exercise mode. Surface electromyography (sEMG) recorded muscle activation of the biceps brachii, triceps brachii, anterior deltoid, posterior deltoid, rectus abdominis, and erector spinae. BWS resistance load was measured using a force transducer. Standing maximal voluntary isometric contractions of the elbow flexors recorded at 90° were used to determine the isometric force decrement and rate of fatigue (ROF) during exercise. sEMG and resistance load data were divided into 25% contraction duration bins throughout the concentric phase. BWS resulted in a 67.7?±?7.4% decline in resistance load throughout the concentric phase (p?≤?0.05). As a result, BB elicited higher mean resistance loads (31.4?±?4.0?kg) and biceps brachii sEMG (84.7?±?27.8% maximal voluntary isometric contractions, MVIC) compared with BWS (20.4?±?3.4?kg, 63.4?±?21.6% MVIC). No difference in rectus abdominis or erector spinae sEMG was detected between exercise modes. Isometric force decrement was greater during BWS (?21.7?±?7.0?kg) compared with BB (?14.9?±?4.7?kg); however, BB (?3.0?±?0.8?kg/set) resulted in a steeper decline in ROF compared with BWS (?1.7?±?0.6?kg/set). The variable resistance loading and greater isometric force decrement observed suggest that select BWS exercises may resemble variable resistance exercise more than previously considered.     

运动预适应对过度训练大鼠心肌缺血缺氧损伤及血清MDA影响的研究

[目的]：研究运动预适应对过度训练大鼠心肌缺血缺氧形态影响及血清MDA.[方法]：将鼠随机分为安静对照组、一般训练组、过度训练组、运动预适应组.安静对照组常规饲氧,不加干预;一般训练组第1-2w常规饲养,第3-4w进行无负重游泳运动,每次游泳1h/d,每周游泳6天.过度训练组第1-2w常规饲养,第3-4w每天进行一次尾部负重3％体重的负荷进行力竭性游泳,每周游泳6天.运动预适应组第1-2W大鼠每天尾部负重3％体重负荷进行间歇性游泳运动一次,每天游泳15 min,休息5 min,重复3次,6 d/周,周日休息,第3-4周运动与过度训练组的第3-4周训练一致.训练结束后取材,进行常规HE染色和HBEP染色并摄片,测血清MDA.[结果]：HE染色,过度训练组肌纤维排列紊乱,部分肌纤维界限模糊.运动预适应组肌纤维轮廓较清楚.HBEP染色过度训练组有若干片状的红色缺血缺氧部位;运动预适应组心肌缺血缺氧改变程度比过度训练组明显减轻.运动各组大鼠血清MDA均高于安静对照组;过度训练组高于一般训练组和运动预适应组.[结论]：运动预适应可以降低过度训练大鼠血清MDA的含量,对心肌缺血缺氧性损伤产生保护作用.     

不同运动量训练对大鼠血睾酮及相关指标的影响

为探讨运动量与血睾酮及相关指标的关系，对大鼠进行小运动量和大运动量两种训练，观察不同运动量对大鼠血清总睾酮(TT)、游离睾酮(FT)和皮质酮(C)浓度的影响。结果显示：小运动量组大鼠血清TT、FT和C均未出现明显下降；大运动量组大鼠血清TT、FT和C均出现显著性降低，并且TT／C值下降幅度达40．22％。因此认为，过度训练引起运动性低血睾酮，适度的运动量训练可以避免低血睾酮；血清游离睾酮的极度低下是引起低血睾酮的直接因素；血清皮质酮浓度降低反映机体应激能力低下；TT／C值可作为判断过度训练的参考指标。     

不同负荷运动训练对大鼠红细胞膜特性的影响

通过实验研究得出以下结论:(1)一次急性运动可造成红细胞的破坏增多,但小负荷的运动训练可以通过增强机体的抗氧化能力,改善红细胞膜性能等途径,最终增加动物血液中红细胞的数量,使其有氧代谢能力及抵抗力竭运动造成的能力均提高。大负荷的训练结果不但使红细胞的破坏增加,且单个红细胞的机能也明显下降,在训练结束后可能发生运动性贫血。(2)大负荷训练后RBCM流动性下降,与其丙二醛(MDA)含量及抗氧化酶SOD活性的变化高度相关。     

运动对大鼠血浆vWF和ET的影响

为了研究力竭性运动及其不同负荷的运动训练对大鼠血管内皮细胞内分泌功能的影响,通过对大鼠进行力竭性运动试验以及进行为期8 w的不同负荷的游泳训练,测定血浆vWF和ET含量。结果表明,急性力竭性运动可能导致机体缺血、缺氧以及心血管内皮细胞的损伤引起血浆vWF和ET含量显著升高;中、小负荷的运动训练可以降低内皮细胞ET的分泌,而大负荷的运动训练可以促进内皮细胞ET的分泌,但是不同负荷的运动训练均使血浆vWF含量显著升高,其机制有待于进一步研究。     

Inspiratory muscle warm-up and inspiratory muscle training: separate and combined effects on intermittent running to exhaustion

In the present study, we examined the independent and combined effects of an inspiratory muscle warm-up and inspiratory muscle training on intermittent running to exhaustion. Twelve males were recruited to undertake four experimental trials. Two trials (Trials 1 and 2) preceded either a 4-week training period of 1 × 30 breaths twice daily at 50% (experimental group) or 15% (control group) maximal inspiratory mouth pressure (PImax). A further two trials (Trials 3 and 4) were performed after the 4 weeks. Trials 2 and 4 were preceded by a warm-up: 2 × 30 breaths at 40% PImax. Pre-training PImax and distance covered increased (P < 0.05) similarly between groups after the warm-up (~11% and ~5-7% PImax and distance covered, respectively). After training, PImax increased by 20 ± 6.1% (P < 0.01; d = 3.6) and 26.7 ± 6.3% (P < 0.01; d = 3.1) when training and warm-up were combined in the experimental group. Distance covered increased after training in the experimental group by 12 ± 4.9% (P < 0.01; d = 3.6) and 14.9 ± 4.5% (P < 0.01; d = 2.3) when training and warm-up interventions were combined. In conclusion, inspiratory muscle training and inspiratory muscle warm-up can both increase running distance independently, but the greatest increase is observed when they are combined.     

Changes in respiratory muscle and lung function following marathon running in man

Respiratory muscle fatigue has been reported following short bouts of high-intensity exercise, and prolonged, moderate-intensity exercise, as evidenced by decrements in inspiratory and expiratory mouth pressures. However, links to functionally relevant outcomes such as breathing effort have been lacking. The present study examined dyspnoea and leg fatigue during a treadmill marathon in nine experienced runners. Maximal inspiratory and expiratory pressure, peak inspiratory and expiratory flow, forced vital capacity, and forced expiratory volume in one second were assessed before, immediately after, and four and 24 hours after a marathon. During the run, leg effort was rated higher than respiratory effort from 18 through 42 km (P < 0.05). Immediately after the marathon, there were significant decreases in maximal inspiratory pressure and peak inspiratory flow (from 118 +/- 20 cm H(2)O and 6.3 +/- 1.4 litres x s(-1) to 100 +/- 22 cm H(2)O and 4.9 +/- 1.5 litres x s(-1) respectively; P < 0.01), while expiratory function remained unchanged. Leg maximum voluntary contraction force was significantly lower post-marathon. Breathing effort correlated significantly with leg fatigue (r = 0.69), but not inspiratory muscle fatigue. Our results confirm that prolonged moderate-intensity exercise induces inspiratory muscle fatigue. Furthermore, they suggest that the relative intensity of inspiratory muscle work during exercise makes some contribution to leg fatigue.