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The effect of breathing pattern retraining on performance in competitive cyclists

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Abstract

The increased work of breathing associated with intense cycling has been identified as a factor that may negatively affect cycling performance. The aerodynamic position, abnormal respiratory mechanics either at rest or during exercise, and the development of a tachypnoeic breathing pattern are factors known to increase the work of breathing. Breathing pattern retraining aims to decrease the work of breathing by delaying the onset of dynamic hyperinflation and the recruitment of accessory breathing muscles. To date no studies have investigated the performance, physiological and perceptual consequences of manipulating breathing pattern in trained cyclists. Purpose: The aim of the present study was to investigate the effect of breathing pattern retraining on 20-km time trial performance and respiratory and metabolic measures in competitive cyclists. Method: Twenty-four competitive male cyclists (age 37.7 ± 8.6 years, mean ± SD; peak 4.34 ± 0.47 L·min-1) were match paired on 20-km time trial performance and assigned at random to either an intervention group (breathing pattern retraining; N = 12) or control group (N = 12). 20-km time trial performance, pulmonary function and the physiological and perceptual response during a maximal incremental cycle step test were assessed pre- and post-intervention. The intervention group underwent four weeks of specific breathing pattern retraining using exercises designed to reduce dynamic hyperinflation and optimise respiratory mechanics. The control group attended the laboratory once a week during this period and performed a 10 minute sub-maximal ride wearing a biofeedback breathing harness. The control group was led to believe the purpose for their participation was to investigate the effect that maximal exercise had on breathing pattern, and to test the reliability of the breathing harness. There was no attempt to modify the breathing pattern of the control group. Data were analysed using an MS Excel spreadsheet designed for statistical analysis. The uncertainty in the effect was expressed as 90% confidence limits and a smallest worthwhile effect of 1.0% was assumed. Results: The intervention group showed substantial improvements in 20-km time trial performance (-1.5 ± 1.1%) and incremental power (3.2 ± 3%). Additionally, breathing frequency (-13.2 ± 8.9%; -9.5 ± 8.4%), tidal volume (10.6 ± 8.5%; 9.4 ± 7.6%), inspiratory time (10.1 ± 8%; 9.4 ± 7.7%), breathing RPE (-30 ± 33.9%; -24.7 ± 28.1%) and leg RPE (-27.9 ± 38.5%; -24.7 ± 28.2%) were all positively affected at lactate threshold and lactate turn point. No positive changes were observed in the control group for 20-km time trial performance (0.0 ± 1.0%), incremental power (-1.4 ± 3.5%), breathing frequency (-1.6 ± 8.0%; -2.0 ± 7.9%), tidal volume (0.9 ± 7.2%; 2.9 ± 9.4%), breathing RPE (16.1 ± 50.2%, 24.8 ± 43%) or leg RPE (13.4 ± 39.6%; 19.9 ± 43.2%) . Conclusion: These results provide evidence of the performance enhancing effect of four weeks of breathing pattern retraining in cyclists. Furthermore, they suggest breathing pattern can be retrained to exhibit a controlled pattern, without a tachypnoeic shift, during high intensity cycling. Additionally, these results indicate breathing pattern retraining attenuates the respiratory and peripheral perceived effort during incremental exercise. Key words: Breathing pattern disorders, retraining, blood stealing, cycling, performance, power output, respiratory mechanics, perceived exertion, 20km-TT

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... Recent reviews have explored the various mechanisms that may cause breathing to limit physical performance during exercise (Amann, 2012;Dempsey et al., 2020), but little work has attempted to address these mechanisms or improve breathing directly during exercise. Although running is both one of the most popular (Statista, 2018) and well-studied physical activities, very few studies have directly investigated the use of breathing techniques during running as done during Yoga, meditation, and cycling (Vickery, 2008;Saoji et al., 2019). Running deserves special attention not only for its immense global popularity but also because runners are driven by a complex mix of psychological and emotional motives (Ogles et al., 1995;Pereira et al., 2021). ...
... Several studies have demonstrated remarkable plasticity of V T in healthy individuals at submaximal intensities (Vickery, 2008;Bahensky et al., 2019;Cleary, 2019;Bahensky et al., 2020). ...
... Ventilatory efficiency and overall BP are considered the result of complexity in a welladjusted system (Benchetrit, 2000); any pertubations could be not only cognitively demanding, but also energetically costly. On the other hand, studies have shown that positive BP changes can be habituated over time periods spanning 2-6 months (Vickery, 2008;Dallam et al., 2018;Bahensky et al., 2019Bahensky et al., , 2021. It is unknown when exactly BP changes occur and under what conditions. ...
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Running is among the most popular sporting hobbies and often chosen specifically for intrinsic psychological benefits. However, up to 40% of runners may experience exercise-induced dyspnoea as a result of cascading physiological phenomena, possibly causing negative psychological states or barriers to participation. Breathing techniques such as slow, deep breathing have proven benefits at rest, but it is unclear if they can be used during exercise to address respiratory limitations or improve performance. While direct experimental evidence is limited, diverse findings from exercise physiology and sports science combined with anecdotal knowledge from Yoga, meditation, and breathwork suggest that many aspects of breathing could be improved via purposeful strategies. Hence, we sought to synthesize these disparate sources to create a new theoretical framework called “Breath Tools” proposing breathing strategies for use during running to improve tolerance, performance, and lower barriers to long-term enjoyment.
... Genelde insan bedeninin sınırlarını zorlayan bütün kıvraklık ve canlılık durumlarını kapsayan benzer ilkel beden pozisyonlarını aynı unsurları çağrıştırmaktadır. 27 Sonucunda ise konsantrasyon ve nefes kontrolü aracılığıyla kişinin sırasıyla her omurgasını duyumsayacak şekilde omurga, diyafram ve fiziksel eksen hislerini birleştirerek bu hissi en üst seviyeye çıkaracağını belirtmiştir. 30 Performans sırasında antrenörlerin asıl amacı alınan oksijenin verimli ve efektif olarak vücut içerisinde kullanılıp sahaya yansıtılmasıdır. ...
... Nefes almanın yeniden eğitilmesinde özellikle dinamik hiperinflasyon ve solunum kaslarının devreye alınması modelini içeren ve hem istirahatte hem de yük altında solunum modellerini devreye sokan bir strateji gerekmektedir. 4 Özel popülasyonlar üzerinde yapılan bazı araştırmalarda, KOAH hastaları ve ilişkili hastalıklarda diyafragmatik solunum modellerinden dudak solunumu yaparak iyileştirmeye çalışılmıştır. 13 2007 yılında Vickely'nin yaptığı araştırma bisikletçiler üzerinde ekspirasyon süresini uzatacak bir model ele alınarak gerçekleştirilen nefes stratejisinin güç üzerinde olumlu bir etkiye sahip olduğunu belirlenmiştir 27 . Respirasyon antrenmanlarının araş- tırıldığı bir meta-analizde ise solunum modellerinin antrene edilmesinin sporcuların performansını arttırabileceği belirtilmiştir. ...
... Son zamanlarda yapılan araştırmalar, abdominal oyuk tekniğinin aslında omurga stabilitesini azalttığını göstermiştir ve abdominal destekleme tekniğinin abdominal oyuk tekniğine kıyasla daha uygulanabilir bir yöntem olduğu gösterilmiştir. 18,27 Abdominal destekleme tekniğinin bir diğer önemli rolü, yapılacak eyleme göre şekillendirilmesi ve nefesin sürekli olarak devamına izin vermesidir. Abdominal oyuk tekniği ise Resim 2'de görüldüğü gibi karın bölgesinin içeri çekilmesini içerdiğinden dolayı bu esnada nefes alışverişine devam etmek mümkün değildir. ...
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Core stabilizasyon terimi son yıllarda sportif performans ve sağlık için egzersiz uzmanlarının ya-kından takip ettikleri, gelişimi ve ilerleme süreçleri için çeşitli stratejiler kullanarak faydalandıkları bir kavram olarak karşımıza çıkmaktadır. Son dönemde birçok araştırmanın ortaya çıkmasıyla muğlak alan-larının daha da üzerine gidilen bu kavram, popülari-tesinin her geçen gün artması nedeniyle daha fazla (21-23 Mayıs 2017, Bursa)'nde sözel olarak sunulmuştur. ÖZET Diyaframın core bölgesi stabilitesindeki önemi, birleşik atletik faaliyetlerde, kuvvet ve hareketi optimum şekilde üretmek, aktarmak ve kontrol etmek için gövdenin pelvis üzerindeki konumunu ve hareketini kontrol etme yeteneğidir. Bu çalışmanın amacı, core bölgesi stabilite-sinde diyafram nefesinin öneminin anlatılması ve iyileştirme stratejile-rinin belirlenmesidir. Panjabi'ye göre, bu bütünlüğü koruyabilmek için, merkezi sinir sistemi (kontrol), iskelet sistemi (pasif) ve kas sistemi (aktif) birlikte çalışır. Bu sistemlerin bir bileşenindeki fonksiyon bo-zukluğunun diğer sistemlerin bunu telafi etmesine, bir veya birden fazla sistemin uzun vadeli adaptasyonuna ve sistemlerin bileşenlerinin zarar görmesine neden olabileceği düşünülmektedir. Bu nedenle, aslında omurganın stabilitesinin sadece kas kuvvetine değil, merkezi sinir sis-temine uygun duyu girdisine bağlı olduğu anlaşılmıştır. Diyaframın eş-zamanlı stabilizasyonda ve solunum sisteminde rolü olması nedeniyle değerlendirme, sırtüstü, yüzüstü, oturarak ve ayakta durmayı içermeli-dir. Değerlendirme sonucunda diyafram nefesinin öğrenilmesi sağlan-malı ve doğru nefes tekniği etkin bir şekilde sahada uygulanacak hareket modellerine adapte edilmelidir. Eğer doğru bir diyafram kulla-nımı sağlanamıyor ise, performans sırasında göğüsten alınan nefes ne-deniyle daha fazla oksijen alma ihtiyacı hissedilecek, bu da çok daha sık nefes alışverişine neden olacak ve sporcunun normalden daha önce yo-rulmasına sebep olabilecektir. Kuvvet ve kondisyon antrenörleri, daha iyi solunum alışkanlıklarının core stabilizasyonunu olumlu olarak et-kileyebileceği ve sporcunun genel kondisyon seviyesinin iyileştirebi-leceği için sporcuların solunum modellerini değerlendirmeyi ve yeniden eğitmeyi düşünmelidir. Anah tar Ke li me ler: Diyafram; core stabilizasyonu; nefes ABS TRACT The importance of the diaphragm in the stability of the core region is the ability to control the position and movement of the trunk on the pelvis in optimal athletic activities to optimally produce, transmit and control force and movement. The aim of this study is to explain the importance of diaphragm breathing in core region stability and to determine improvement strategies. According to Panjabi, the central nervous system (control), the skeletal system (passive) and the muscular system (active) work together to maintain this integrity. It is also contemplated that dysfunction in one component of these systems may cause other systems to compensate for this, long-term adaptation of one or more systems, and damage to the components of the systems. Thus, it has been found that the stability of the spine depends not only on muscle strength but also on sensory input to the central nervous system. Because the diaphragm has a role in simultaneous stabilization and respiratory system, the assessment should include supine, prone, sitting and standing. As a result of the evaluation, the diaphragm breath should be learned and this should be adapted effectively to the movement patterns to be applied in the field. If proper diaphragm use cannot be achieved, there will be a need for more oxygen to breathe from the chest during performance, which will cause more frequent breathing and may cause the athlete to get tired earlier than usual. Strength and conditioning coaches should consider evaluating and retraining their breathing patterns for athletes, as better breathing habits can positively affect core stabilization and ultimately improve the athlete's overall fitness level.
... A respiração por sua vez, também é considerada um preditor para o desempenho dos indivíduos, caracterizada uma ação passiva, por vezes negligenciada durante o exercício, ocasionando padrões respiratórios irregulares, que podem ser consequência de uma mecânica respiratória alterada (VICKERY, 2007). Respirar de forma adequada facilita o controle da atividade cardíaca e favorece o condicionamento físico, uma vez que a respiração ritmada e controlada promove estabilidade dos batimentos cardíacos e uma melhor execução do mesmo trabalho com menos esforços (SCHÖRNER; FRANCO, 2015). ...
... Disfunções no padrão respiratório podem ter efeitos negativos no desempenho funcional dos ciclistas por razões como: taquipneia e uso em excesso das musculaturas acessórias da respiração (LUCÍA et al. 1999;VICKERY, 2007). A espirometria fornece uma análise da mecânica respiratória afetada, de acordo com limitações do fluxo de ar (BLAGER, 2000;VICKERY, 2007). ...
... Disfunções no padrão respiratório podem ter efeitos negativos no desempenho funcional dos ciclistas por razões como: taquipneia e uso em excesso das musculaturas acessórias da respiração (LUCÍA et al. 1999;VICKERY, 2007). A espirometria fornece uma análise da mecânica respiratória afetada, de acordo com limitações do fluxo de ar (BLAGER, 2000;VICKERY, 2007). ...
Article
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O ciclismo consolidou-se a partir do uso da bicicleta, inicialmente como um meio de transporte secular, desenvolvido com fins de transporte e passeio, transformado em uma prática esportiva complexa de intensidade variada. O intuito final da prática esportiva de forma continua, é o condicionamento físico, o qual visa aumentar da capacidade física e motora do organismo, como forma de executar atividade musculares especificas, obter melhores resultados e consequente aumento da performance individual. O objetivo deste trabalho foi avaliar a capacidade pulmonar em ciclistas residentes na cidade de Maceió-AL. Trata-se de um estudo transversal e descritivo, com coleta de dados antropométricos e da capacidade pulmonar. Como critérios de inclusão do estudo, considerou-se indivíduos do sexo masculino; com idade ≥ 18 anos; que realizassem a prática do ciclismo por um período superior há 3 meses; participantes ou não de provas federado- -oficiais; e residentes na cidade de Maceió/Alagoas. Participaram do estudo 16 ciclistas do sexo masculino, com média de idade 31,18±7,78 anos e tempo médio de prática de ciclismo de 32,65±7,81 meses. Como resultados, observou-se que 88% dos ciclistas obtiveram valores considerados adequados de capacidade pulmonar e apenas 19% obtiveram distúrbio restritivo.
... 4,8,9 Research is providing new knowledge which underpins the comprehensive role physiotherapy can provide in optimizing the breathing pattern, reducing/eliminating symptoms and facilitating wellbeing. [10][11][12] To date the physiotherapy literature on the topic of breathing pattern disorders and breathing re-education is sparse. Breathing pattern disorders are fast becoming recognized within the speciality area of musculoskeletal and sports physiotherapy 11 and private practice, 13 whilst still having a significant role in the more likely areas of lung disease 5,6 and of anxiety. ...
... [10][11][12] To date the physiotherapy literature on the topic of breathing pattern disorders and breathing re-education is sparse. Breathing pattern disorders are fast becoming recognized within the speciality area of musculoskeletal and sports physiotherapy 11 and private practice, 13 whilst still having a significant role in the more likely areas of lung disease 5,6 and of anxiety. 9,14 A Developing Understanding of Breathing Pattern Disorders ...
... Research is now beyond the capacity of ventilation and starting to look at the muscles of respiration and breathing patterns. 11 The fundamental goal of our system is the protection of oxygen delivery to the respiratory muscles, thus ensuring the ability to maintain pulmonary ventilation, proper regulation of arterial blood gases and pH and overall homeostasis. ...
Article
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Background: Breathing pattern disorders (BPDs), historically known as hyperventilation syndrome, are being increasingly recognized as an entity of their own. Breathing patterns reflect the functioning of the respiratory system and the biomechanical system as well as the cognitive state. Clinical relevance: It is essential, therefore, that physiotherapists from all areas of specialty consider the assessment and treatment of a patient's breathing pattern. New literature is emerging which underpins the relevance of BPD in patients with lung disease, anxiety, and also in the comparatively new area of sport performance. Physiotherapists are well placed to treat people with disordered breathing because of their clinical skills and comprehensive knowledge base. Current treatment is briefly reviewed in this paper, and trends for future treatment are also addressed. Conclusion: The potential for improving the patient's state, by optimizing their breathing pattern in all their activities, is an important development in physiotherapy. It is a developing area of knowledge which is pertinent to physiotherapy practice as it develops in a biopsychosocial model.
... However, it is imperative that the breath is diaphragmatic, thus deep and full-not just a short breath located high up in the chest. Ideally, you also want players to systematically practice this type of breathing far in advance (Vickery, 2007). An important part of this advice for a penalty shootout is that it also gives the players something to focus on at a stressful moment, which in itself will anchor a player's focus onto something different than their tension and anxiety. ...
... Abnormální dýchání, známé jako hrudní dýchání, zahrnuje dýchání v horní části hrudníku s viditelně zvětšenou pohyblivostí horní části hrudníku oproti spodní části hrudníku (Chaitow, Bradley & Gilbert, 2002). Poruchy dechového stereotypu jsou definovaný jako nevhodné dýchání, které je natolik trvalé, že způsobí změny v organismu bez zjevné organické příčiny (Vickery, 2008). Poruchy dechového stereotypu (PDS) jsou přítomny u různých jedinců s muskuloskeletální poruchou (Chaitow, 2004; Kapreli et al., 2009Perri & Halford, 2004;Roussel, Nijs & Truijen, 2007;Smith, Russell & Hodges, 2006). ...
Article
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Breathing is one of the basic life functions. With disorder of respiratory stereotype, we encounter across the entire spectrum of the population. Proper breathing is essential for the optimal function of the musculoskeletal system. The correct position and function of the diaphragm affects respiratory function and tolerance to stress. The aim of this work was to investigate the course of respiratory waves during relax and deep breathing on students of Physical education and Sports, who regularly take part in some sporting activity. For investigation, we used the stereotype of respiratory muscle dynamometer. While analysing respiratory movements we work with the concepts of the three sectors chest. Evaluation of the data was performed using Microsoft Excel 2016 and Statistica 12. Differences were discovered in participation of individual sectors in chest during relax and deep breathing and disorders of respiratory stereotype. Dýchání je jednou ze základních životních funkcí. S poruchami dechového stereotypu se setkáváme napříč celým spektrem populace. Správné dýchání je nezbytným předpokladem optimálního fungování pohybového aparátu. Správná poloha a funkce bránice ovlivňuje dechové funkce a toleranci na zátěž. Cílem práce bylo vyšetřit průběh dechové vlny během klidového a prohloubeného dýchání u studentů Tělesné výchovy a sport, kteří se pravidelně věnují nějaké sportovní aktivitě. Pro vyšetření dechového stereotypu jsme použili svalový dynamometr. Při analýze dýchacích pohybů vycházíme z koncepce tří sektorů hrudníku. Vyhodnocení dat jsme provedli v programu Microsoft Excel 2016 a Statistica 12. Byly zjištěny rozdíly v zapojení jednotlivých sektorů hrudníku při klidovém a prohloubeném dýchání a poruchy dechového stereotypu.
... Thoracic breathing is produced by the accessory muscles of respiration (including sternocleidomastoid, upper trapezius, and scalene muscles), dominating over lower rib cage and abdominal motion (Chaitow, Bradley, & Gilbert, 2002). Vickery (2008) suggested that decreased abdominal motion, relative to upper thoracic motion, confirms poor diaphragm action. In our study, the observed changes in chest excursion can be a confirmation of improvement of breathing pattern. ...
Article
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Postural control and breathing are mechanically and neuromuscularly interdependent. Both systems- of spinal stability and respiration- involve the diaphragm, transversus abdominis, intercostal muscles, internal oblique muscles and pelvic floor muscles. The aim of the study was to evaluate the effect of exercises activating deep stabilizer muscles on postural control and quality of breathing movements. Eighteen volunteers (25,7 ± 3,5) were recruited from the general population. All the subjects implemented an exercise program activating deep muscles. Head, pelvic and trunk positions in the sagittal and frontal planes were assessed with the photogrammetric method. Breathing movements were estimated with the respiratory inductive plethysmography. The results indicate that the use of deep muscle training contributed to a significant change in the position of the body in the sagittal plane (p = 0.008) and the increase in the amplitude of breathing (p = 0.001).
... Normal breathing requires adequate use and functionality of the diaphragm muscle 12 . rib cage 13 .Breathing pattern disorders (BPD), defined as inappropriate breathing 9 , are present in a variety of individuals with musculoskeletal dysfunction 14,15,6,7,8 . Hodges et al 10 since the diaphragm performs both postural and breathing functions, disruption in one function could negatively affect the other. ...
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Objective: To find the effectiveness of 90/90 bridge with ball and balloon exercise in asymptomatic subjects with suboptimal breathing. Design: Randomized control trial Participants: 42 asymptomatic subjects within the age group of 18 to 25 years. 20 subjects selected on the basis of inclusion and exclusion criteria, Lottery method was used to assign the subjects, to experimental group (N=10) and control group (N=10). Outcome Measures: Forced Vital Capacity (FVC), forced expiratory volume in 1 second (FEV1) and FEV1/FVC ratio. Intervention: Asymptomatic subjects with suboptimal breathing with reduced FVC, FEV1 and FEV1/FVC ratio were included. Therapeutic exercise called 90/90 bridge with ball and balloon exercise was taught to the subjects in experimental (n=10) group for a period of 6 weeks once in a day with 4 repetition, 5 days in a week. The pre and post exercise spirometry comparison was done to find the effectiveness of 90/90 bridge with ball and balloon exercise in asymptomatic subjects with suboptimal breathing. Control group (n=10) had no specific intervention. Results: Post exercise there was a significant improvement in FEV1 (p value 0.002), FEV1/FVC (p value 0.005) and no significant improvement in FVC (p value 0.170) in experimental group whereas in controlled group no significant improvement was seen in all the parameters. Conclusion: 90/90 bridge with ball and balloon exercise helps in optimizing breathing in asymptomatic individual with suboptimal breathing. The present study showed that 90/90 BBE exercise is effective and improves the lung volumes in individuals with reduced lung volumes and suboptimal breathing. Individuals who were taught exercise showed significant improvement in FEV1 and FEV1/FVC where as in control group no significant improvement was seen. Keywords: FVC; Breathing Exercise; FEV1; FEV1/FVC, Sub Optimal Breathing
... Published research protocols generally follow treatment principles that focus on education about the condition, reassurance, abdominal breathing retraining, breathing rate and depth control, breathing retraining in progressively taxing postures such as walking, recognition of triggers, and control of symptoms during an episode and manual therapy [18,24,25]. Studies have demonstrated a reduction in respiratory symptoms and hospital visits and an improvement in health-related QoL and athletic performance over relatively short periods of two to eight clinical visits with a physiotherapist [25,33,[42][43][44]. Furthermore, benefits have been maintained in some groups from 6 months to 5 years [33,42]. ...
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Key points Excessive exercise-induced shortness of breath is a common complaint. For some, exercise-induced bronchoconstriction is the primary cause and for a small minority there may be an alternative organic pathology. However for many, the cause will be simply reaching their physiological limit or be due to a functional form of dysfunctional breathing, neither of which require drug therapy. The physiological limit category includes deconditioned individuals, such as those who have been through intensive care and require rehabilitation, as well as the unfit and the fit competitive athlete who has reached their limit with both of these latter groups requiring explanation and advice. Dysfunctional breathing is an umbrella term for an alteration in the normal biomechanical patterns of breathing that result in intermittent or chronic symptoms, which may be respiratory and/or nonrespiratory. This alteration may be due to structural causes or, much more commonly, be functional as exemplified by thoracic pattern disordered breathing (PDB) and extrathoracic paradoxical vocal fold motion disorder (pVFMD). Careful history and examination together with spirometry may identify those likely to have PDB and/or pVFMD. Where there is doubt about aetiology, cardiopulmonary exercise testing may be required to identify the deconditioned, unfit or fit individual reaching their physiological limit and PDB, while continuous laryngoscopy during exercise is increasingly becoming the benchmark for assessing extrathoracic causes. Accurate assessment and diagnosis can prevent excessive use of drug therapy and result in effective management of the cause of the individual’s complaint through cost-effective approaches such as reassurance, advice, breathing retraining and vocal exercises. This review provides an overview of the spectrum of conditions that can present as exercise-­induced breathlessness experienced by young subjects participating in sport and aims to promote understanding of the need for accurate assessment of an individual’s symptoms. We will highlight the high incidence of nonasthmatic causes, which simply require reassurance or simple interventions from respiratory physiotherapists or speech pathologists.
... 5 Abnormal breathing, known as thoracic breathing, involves breathing from the upper chest, evidenced by greater upper rib cage motion, compared to the lower rib cage. 6 Breathing pattern disorders (BPD), defined as inappropriate breathing that is persistent enough to cause symptoms with no apparent organic cause, 7 are present in a variety of individuals with musculoskeletal dysfunction. 8,9,10,11,12 BPD could be a risk factor for the development of the dysfunction, a result of the dysfunction itself, and an important, clinically measurable attribute to consider in those with musculoskeletal pain. ...
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Experimental design. Normal breathing mechanics play a key role in posture and spinal stabilization. Breathing Pattern Disorders (BPD) have been shown to contribute to pain and motor control deficits, which can result in dysfunctional movement patterns. The Functional Movement Screen™ (FMS™) has been shown to accurately predict injury in individuals who demonstrate poor movement patterns. The role BPD play on functional movement is not well established. Furthermore, there is currently no single test to clinically diagnose BPD. A variety of methods are used, but correlations between them are poor. To examine the relationship between BPD and functional movement and identify correlations between different measures of BPD. Breathing was assessed in 34 healthy individuals using a multi-dimensional approach that included biomechanical, biochemical, breathing related symptoms, and breathing functionality measures. Movement was assessed using the FMS™. Analysis, involving independent t-tests and Pearson correlation were performed to identify associations between measures. Individuals who exhibited biochemical and biomechanical signs of BPD were significantly more likely to score poorly on the FMS™. These studied measures of BPD correlated highly with each other. These results demonstrate the importance of diaphragmatic breathing on functional movement. Inefficient breathing could result in muscular imbalance, motor control alterations, and physiological adaptations that are capable of modifying movement. These findings provide evidence for improved breathing evaluations by clinicians. 2B.
Article
Abstract Background: The worldwide prevalence of obesity and low back pain (LBP) has recently dramatically increased and is mainly indicated among postpartum women, leading to a range of adverse health consequences. Objective: This study aimed to investigate the effects of 6 weeks of Dynamic Neuromuscular Stabilization training (DNS) in obese postpartum women with LBP. Method: This was a pretest-posttest study design. The study was conducted with 40 obese postpartum women with LBP randomized to receive DNS (n = 20) or General Exercise (GE, n = 20) 6 times a week for 6 weeks. The data were gathered before and after the 6-week intervention. Results: Forty participants completed the study (mean ± SD, age 29.30 ± 3.77 years; weight 88.10 ± 6.09 kg; height 165.40 ± 6.31 cm; and BMI, 32.19 ± 1.07 kg/m2). The overall group-by-time interaction was significant for Numeric Pain-Rating Scale, Modified Oswestry Disability Questionnaire, Fear-Avoidance Beliefs Questionnaire, Inspiration and Expiration Breath Hold Time, and Respiratory Rate outcomes. The global rating of change was significantly different between groups (p < .05). The rate of improvement was higher in the DNS group compared to the GE group in all 6 tests. Conclusion: The present study confirms that DNS is applicable in obese postpartum women with LBP and effectively improved NPRS, MODQ, FABQ, BHT, and RR. It is clinically suggested that DNS is imperative based on ideal ontogenetic patterns to attain optimal results for obese postpartum women with LBP. Keywords low back pain, dynamic neuromuscular stabilization, general exercise, respiratory function, obese postpartum women
Research
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Existe escasa evidencia reportada, en tiempo real, durante los entrenamientos y la competición, referente a las demandas fisiológicas y mecánicas (aceleraciones), que acontecen en el juego del voleibol de élite. Esta carencia es todavía aun mayor desde que se modificaron las reglas en el año 1999. La principal modificación es la introducción del líbero y la sustitución del central cuando llega a la zona defensiva por el líbero. De esta manera mientras un central está en la red (en ataque), el otro central, que fue sustituido por el líbero al llegar a la zona defensiva, se encontrará descansando. Generándose de esta manera una sustancial mejora en la capacidad de recepción y de defensa de los equipos. Esta modificación reglamentaria indujo un cambio en los aspectos tácticos y físicos del juego que devino a acciones más explosivas y de menor duración, al mismo tiempo, además, generaron una mayor especialización en los jugadores, por lo que generó un impacto en su perfil fisiológico y neuromuscular (Sheppard et al., 2009). Gran parte de los estudios de análisis de tiempo-movimiento durante el entrenamiento y la competición se centran en la cantidad de saltos y la frecuencia con la que estos ocurren (Sheppard et al., 2009), comparados por puesto y nivel de calificación (Sheppard et al, 2007; Sheppard et al., 2009; Hasegawa et al., 2002). Por otro lado muchos estudios analizan en forma aislada la biomecánica del salto, sobre todo la técnica, la cinemática y la cinética durante la caída (Tillman et al., 2004; Bisseling y Hof, 2006; Suda et al., 2007; Cronin et al., 2008; Wagner et al., 2009; Marquez et al., 2009; Hughes et al., 2010; Hsienhand y Huang, 2012), así como su relación con mecanismos de producción de lesión (Niell et al., 2007; Bisseling et al., 2008; Janssen et al., 2013; Taylor et al., 2011; Bates et al., 2013; Kulig et al., 2015). Sin embargo, no hemos encontrado estudios que reporten la altura de los saltos durante el entrenamiento y la competición y la carga mecánica que representan los mismos en relación a los procesos de fatiga y lesión por sobreuso. Respecto a las respuestas fisiológicas, los escasos estudios que abordan esta problemática fueron realizados con las reglas antiguas, cuando los partidos tenían una duración superior, con una carga de saltos aún mayor. Hasta la fecha, hemos encontrado un estudio que analizó la evolución de la frecuencia cardíaca durante el entrenamiento y la competición, para permitir estimar la carga del entrenamiento y obtener valores que sirvan como parámetros de control de las sesiones de entrenamiento (Berna Jimenez, 2014). Sin embargo, en este estudio, no utilizaron dispositivos que permitiesen cuantificar, a la vez, la solicitación del aparato cardiovascular y las solicitaciones mecánicas. Existe suficiente evidencia sobre modelos subjetivos de cuantificación de la carga en deportes de equipo tales como el baloncesto (Foster et al., 2001; Anderson et al., 2003; Manzi et al., 2010, Moreira et al., 2012), fútbol (Impellizzeri et al., 2004; Little y Williams, 2007; Alexiou y Coutts, 2008; Coutts et al., 2009; Casamichana et al., 2013; Scott et al., 2013; Fanchini et al., 2015), rugby (Gabbett y Domrow, 2007; Elloumi et al., 2012; (Moreira et al., 2015) y voleibol (Berna Jimenez, 2014; Rodríguez-Marroyo et al., 2014; Freitas et al., 2014). Las herramientas de medida más utilizadas para controlar la carga del entrenamiento se basan en el registro de la frecuencia cardíaca (FC) y la percepción subjetiva del esfuerzo (RPE) . Por medio de la frecuencia cardiaca, por ejemplo, se puede establecer el denominado impulso del entrenamiento (TRIMP) (Banister, 1991), o bien cuantificar la carga en función del tiempo empleado en cada zona de intensidad (Berna Jimez, 2014). Medios actuales más sofisticados utilizando GPS y/o acelerómetros permiten cuantificar la carga del entrenamiento a partir de las velocidades y/o aceleraciones y las distancias recorridas en franjas de velocidad o de aceleración. El GPS no es un instrumento adecuado para el control de las variables mecánicas durante el voleibol porque se juega en estadio cubierto (indoor) impidiendo la correcta señal del GPS. Sin embargo, los acelerómetros permiten cuantificar, las aceleraciones y desaceleraciones producidas durante el entrenamiento y la competición en cualquier terreno de juego. El dispositivo comercial ZephyrTM BioharnessTM, permite monitorizar en tiempo real la carga fisiológica y mecánica del entrenamiento y la competición. Este dispositivo es relativamente nuevo y no existen trabajos publicados en la literatura científica respeto a la utilización del mismo como método de control del voleibol. Teniendo en cuenta esta carencia y el interés del estudio, parece interesante explorar la utilización del ZephyrTM como una herramienta de valoración de la carga de entrenamiento de los jugadores de voleibol. Debido a la escasa fuente de información existente sobre las manifestaciones fisiológicas y mecánicas en el entrenamiento y la competición del voleibol, y la importancia que puede tener contar con mecanismos de control de la carga durante los entrenamientos, el objeto del presente trabajo, ha sido estudiar y comparar, las respuestas fisiológicas y mecánicas de los jugadores de voleibol masculino de elite, durante el entrenamiento y la competición, durante cuatro semanas previas a la celebración del campeonato del mundo de la categoría sub-23.
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The function of the respiratory system is to move oxygen from the air of the environment to the mitochondria of the cells where it is utilized, and move carbon dioxide in the opposite direction. The processes include pulmonary ventilation, diffusion, pulmonary blood flow, gas exchange, mechanics of breathing, control of ventilation, and peripheral gas exchange.
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Respiratory symptoms such as dyspnea (air hunger resulting in labored breathing), cough, and hyperventila- tion may share a complex multifactorial etiology includ- ing genetic predisposition and physiological factors as well as psychological factors, particularly stress. One such respiratory condition is termed vocal cord dysfunction (VCD) and is characterized by closure of the vocal cords during inspiration (breathing in), resulting in wheezing, breathing difficulties, dyspnea, and tightening of the throat and/or chest. Historically, other terms used to denote VCD have included paradoxical vocal fold motion, functional stridor, and psychogenic wheezing. VCD is fre- quently misdiagnosed as asthma and treated with asth- ma medications with little to no improvement. The condi- tion is commonly seen in adolescents and young adults and is more prevalent among competitive athletes. Although the exact prevalence of VCD is not known, it is not uncommon. The diagnosis of VCD is difficult to make, and all possible causes of wheezing and other VCD symp- toms need to be considered. Psychiatric explanations such as anxiety, factitious disorder, and conversion disorder must also be assessed. Without appropriate treatment, VCD symptoms do not resolve and may actually worsen, occasionally leading to hospitalization and invasive med- ical procedures. In this article, we provide an overview of VCD and describe an integrative approach to the treat- ment of VCD in young athletes.
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Paradoxical vocal fold dysfunction (PVFD) is one of many terms used to describe disorders of the upper airway where vocal folds do not present normal patterns during respiration, leading to significant respiratory distress. When symptomatic, patients show varying vocal fold patterns of closure during inspiration, expiration, or combinations of both. Constriction of supraglottic structures also may occur. The airway obstruction can result in life-threatening Emergency Room presentation, leading to intubation and even tracheostomy. Although PVFD affects few patients overall, 10% of those diagnosed with asthma may have PVFD alone or in combination with asthma. Correct diagnosis and treatment are vital to avoid costly and even unnecessary medications and hospitalizations.
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Breathing retraining of patients with Hyperventilation Syndrome (HVS) and/or panic disorder is discussed to evaluate its clinical effectiveness and to examine the mechanism that mediates its effect. In relation to this theoretical question, the validity of HVS as a scientific model is discussed and is deemed insufficient. It is concluded that breathing retraining and related procedures are therapeutically effective, but probably due to principles other than originally proposed, namely decreasing the tendency to hyperventilate. An alternative principle is the induction of a relaxation response, presenting a credible explanation for the threatening symptoms, giving a distracting task to practice when panic may occur, and promoting a feeling of control.
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Objective: The aim of this study was to determine whether whole-body endurance training is associated with increased respiratory muscle strength and endurance. Methodology: Respiratory muscle strength (maximum inspiratory pressure (PImax)) and endurance (progressive threshold loading of the inspiratory muscles) were measured in six marathon runners and six sedentary subjects. Results: PImax was similar between the two groups of subjects but the maximum threshold pressure achieved was greater in marathon runners (90 ± 8 vs 78 ± 10% of PImax, respectively, mean ± SD, P < 0.05). During progressive threshold loading, marathon runners breathed with lower frequency, higher tidal volume, and longer inspiratory and expiratory time. At maximum threshold pressure, marathon runners had lower arterial O2 saturation, but perceived effort (Borg scale) was maximal in both groups. Efficiency of the respiratory muscles was similar in both groups being 2.0 ± 1.7% and 2.3 ± 1.8% for marathon runners and sedentary subjects, respectively. Conclusions: The apparent increase in respiratory muscle endurance of athletes was a consequence of a difference in the breathing pattern adopted during loaded breathing rather than respiratory muscle strength or efficiency. This implies that sensory rather than respiratory muscle conditioning may be an important mechanism by which whole-body endurance is increased.
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7 young, healthy, male subjects performed exercise on bicycle ergometers in two 20 min periods with an interval of 1 h. The first 10 min of each 20 min period consisted of arm exercise (38–62% of Vdot;o2 max for arm exercise) or leg exercise (58–78% of Vdot;o2 max for leg exercise). During the last 10 min the subjects performed combined arm and leg exercise (71–83% of Vdot;o2 max for this type of exercise). The following variables were measured during each type of exercise: oxygen uptake, heart rate, mean arterial blood pressure, cardiac output, leg blood flow (only during leg exercise and combined exercise), arterio-venous concentration differences for O2 and lactate at the levels of the axillary and the external iliac vessels.Superimposing a sufficiently strenuous arm exercise (oxygen uptake for arm exercise 40% of oxygen uptake for combined exercise) on leg exercise caused a reduction in blood flow and oxygen uptake in the exercising legs with unchanged mean arterial blood pressure. Superimposing leg exercise on arm exercise caused a decrease in mean arterial blood pressure and an increased axillary arterio-venous oxygen difference. These findings indicate that the oxygen supply to one large group of exercising muscles may be limited by vasoconstriction or by a fall in arterial pressure, when another large group of muscles is exercising simultaneously.
The purpose of our investigation was to analyse the breathing patterns of professional cyclists during incremental exercise from submaximal to maximal intensities. A group of 11 elite amateur male road cyclists [E, mean age 23 (SD 2) years, peak oxygen uptake (V˙O2peak) 73.8 (SD 5.0) ml · kg−1 · min−1] and 14 professional male road cyclists [P, mean age 26 (SD 2) years, (V˙O2peak) 73.2 (SD 6.6) ml · kg−1 · min−1] participated in this study. Each of the subjects performed an exercise test on a cycle ergometer following a ramp protocol (exercise intensity increases of 25 W · min−1) until the subject was exhausted. For each subject, the following parameters were recorded during the tests: oxygen consumption (V˙O2), carbon dioxide output (V˙CO2), pulmonary ventilation (V˙ E), tidal volume (V T), breathing frequency (f b), ventilatory equivalents for oxygen (V˙ E·V˙O2 −1) and carbon dioxide (V˙ E·V˙CO2 −1), end-tidal partial pressure of oxygen and partial pressure of carbon dioxide, inspiratory (t I) and expiratory (t E) times, inspiratory duty cycle (t I/t TOT, where t TOT is the time for one respiratory cycle), and mean inspiratory flow rate (V T/t I). Mean values of V˙ E were significantly higher in E at 300, 350 and 400 W (P < 0.05, P < 0.05 and P < 0.01, respectively); f b was also higher in E in most moderate-to-maximal intensities. On the other hand, V T showed a different pattern in both groups at near-to maximal intensities, since no plateau was observed in P. The response of t I and t E was also different. Finally, V T/t I and t I/t TOT showed a similar response in both P and E. It was concluded that the breathing pattern of the two groups differed mainly in two aspects: in the professional cyclists, V˙ E increased at any exercise intensity as a result of increases in both V T and f b, with no evidence of tachypnoeic shift, and t E was prolonged in this group at high exercise intensities. In contrast, neither the central drive nor the timing component of respiration seem to have been significantly altered by the training demands of professional cycling.
Article
A simple mathematical model of the chest wall was constructed so that during tidal breathing the relative volume contributions of the rib cage and abdomen/diaphragm could be measured in man, using four mercury-in-rubber strain gauges around the trunk. From the dimensions of the trunk and the change in circumference determined by the four gauges, the separate contributions of rib cage and abdomen/diaphragm could be determined using a purpose-built analog computer. The system was evaluated in 13 laboratory personnel, and in 13 other subjects before and after anaesthesia. There was a linear relationship between tidal volumes computed and measured at the mouth, over the residual volume to (FRC+1 litre) range, with an error of +8%. The relative contribution of rib cage to tidal breathing showed a large scatter from 5 to 42% with a non-significant tendency to decrease with age.
Article
We determined how close highly trained athletes [n = 8; maximal oxygen consumption (VO2max) = 73 +/- 1 ml.kg-1.min-1] came to their mechanical limits for generating expiratory airflow and inspiratory pleural pressure during maximal short-term exercise. Mechanical limits to expiratory flow were assessed at rest by measuring, over a range of lung volumes, the pleural pressures beyond which no further increases in flow rate are observed (Pmaxe). The capacity to generate inspiratory pressure (Pcapi) was also measured at rest over a range of lung volumes and flow rates. During progressive exercise, tidal pleural pressure-volume loops were measured and plotted relative to Pmaxe and Pcapi at the measured end-expiratory lung volume. During maximal exercise, expiratory flow limitation was reached over 27-76% of tidal volume, peak tidal inspiratory pressure reached an average of 89% of Pcapi, and end-inspiratory lung volume averaged 86% of total lung capacity. Mechanical limits to ventilation (VE) were generally reached coincident with the achievement of VO2max; the greater the ventilatory response, the greater was the degree of mechanical limitation. Mean arterial blood gases measured during maximal exercise showed a moderate hyperventilation (arterial PCO2 = 35.8 Torr, alveolar PO2 = 110 Torr), a widened alveolar-to-arterial gas pressure difference (32 Torr), and variable degrees of hypoxemia (arterial PO2 = 78 Torr, range 65-83 Torr). Increasing the stimulus to breathe during maximal exercise by inducing either hypercapnia (end-tidal PCO2 = 65 Torr) or hypoxemia (saturation = 75%) failed to increase VE, inspiratory pressure, or expiratory pressure. We conclude that during maximal exercise, highly trained individuals often reach the mechanical limits of the lung and respiratory muscle for producing alveolar ventilation. This level of ventilation is achieved at a considerable metabolic cost but with a mechanically optimal pattern of breathing and respiratory muscle recruitment and without sacrifice of a significant alveolar hyperventilation.
Dyspnea, leg effort (Borg 0 to 10 scale), ventilation, and heart rate (VEmax/VEcap; HRmax/HRcap expressed as a percentage of capacity) were measured at maximal exercise (cycle ergometer) in 97 patients with chronic airflow limitation (CAL) (FEV, 46.6 +/- 14.23% of predicted) and compared with 320 matched control subjects. Patients with CAL achieved a maximum power output of 86 +/- 39.5 W (60 +/- 23.2% of predicted) compared with 140 +/- 37.5 W (98 +/- 14.5% of predicted) in controls (p less than 0.0001), VEmax/VEcap was 72 +/- 19.3% compared with 53 +/- 18.6% (p less than 0.0001), and HRmax/HRcap was 76 +/- 13.5% compared with 82 +/- 13% (p less than 0.001). These findings were expected. The median intensity of dyspnea was 6 (severe to very severe) and leg effort was 7 (very severe) in both groups, and these findings were unexpected. The patients with CAL were handicapped by an increase in both dyspnea and peripheral muscular effort relative to the actual power output. The rating of dyspnea exceeded leg effort in 25 (26%) of CAL versus 69 (22%) control subjects: the rating of leg effort exceeded dyspnea in 42 (43%) CAL and 117 (36%) control subjects; both were rated equally in 30 (31%) CAL and 134 (42%) control subjects, respectively (NS). VEmax/VEcap and HRmax/HRcap were not significantly different in those limited by dyspnea, leg fatigue, or a combination of both. All values are expressed +/- SD.
Article
Controversy exists whether recruitment of a large muscle mass in dynamic exercise may outstrip the pumping capacity of the heart and require neurogenic vasoconstriction in exercising muscle to prevent a fall in arterial blood pressure. To elucidate this question, seven healthy young men cycled for 70 minutes at a work load of 55-60% VO2max. At 30 to 50 minutes, arm cranking was added and total work load increased to (mean +/- SE) 82 +/- 4% of VO2max. During leg exercise, leg blood flow average 6.15 +/- .511 minutes-1, mean arterial blood pressure 137 +/- 4 mmHg and leg conductance 42.3 +/- 2.2 ml minutes-1 mmHg-1. When arm cranking was added to leg cycling, leg blood flow did not change significantly, mean arterial blood pressure increased transiently to 147 +/- 5 mmHg and leg vascular conductance decreased transiently to 33.5 +/- 3.1 ml minutes-1 mmHg-1. Furthermore, arm cranking doubled leg noradrenaline spillover. When arm cranking was discontinued and leg cycling continued, leg blood flow was unchanged but mean arterial blood pressure decreased to values significantly below those measured in the first leg exercise period. Furthermore, leg vascular conductance increased transiently, and noradrenaline spillover decreased towards values measured during the first leg exercise period. It is concluded that addition of arm cranking to leg cycling increases leg noradrenaline spillover and decreases leg vascular conductance but leg blood flow remains unchanged because of a simultaneous increase in mean arterial blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
Article
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.
Article
In this study we evaluated the physiological and biomechanical responses of 'elite-national class' (i.e., group 1; N = 9) and 'good-state class' (i.e., group 2; N = 6) cyclists while they simulated a 40 km time-trial in the laboratory by cycling on an ergometer for 1 h at their highest power output. Actual road racing 40 km time-trial performance was highly correlated with average absolute power during the 1 h laboratory performance test (r = -0.88; P < 0.001). In turn, 1 h power output was related to each cyclists' V̇O2 at the blood lactate threshold (r = 0.93; P < 0.001). Group 1 was not different from group 2 regarding V̇O(2max) (approximately 70 ml·kg-1·min-1 and 5.01 l·min-1) or lean body weight. However, group 1 bicycled 40 km on the road 10% faster than group 2 (P < 0.05; 54 vs 60 min). Additionally, group 1 was able to generate 11% more power during the 1 h performance test than group 2 (P < 0.05), and they averaged 90 ± 1% V̇O(2max) compared with 86 ± 2% V̇O(2max) in group 2 (P = 0.06). The higher performance power output of group 1 was produced primarily by generating higher peak torques about the center of the crank by applying larger vertical forces to the crank arm during the cycling downstroke. Compared with group 2, group 1 also produced higher peak torques and vertical forces during the downstroke even when cycling at the same absolute work rate as group 2. Factors possibly contributing to the ability of group 1 to produce higher 'downstroke power' are a greater percentage of Type I muscle fibers (P < 0.05) and a 23% greater (P < 0.05) muscle capillary density compared with group 2. We have also observed a strong relationship between years of endurance training and percent Type I muscle fibers (r = 0.75; P < 0.001). It appears that 'elite-national class' cyclists have the ability to generate higher 'downstroke power', possibly as a result of muscular adaptations stimulated by more years of endurance training.
Article
The purpose of this investigation was to investigate the hypothesis that respiration was coupled with the mechanics of the rowing stroke. In the first part of the study, physiologic responses during incremental exercise on the variable-resistance rowing ergometer were compared in 16 untrained female subjects (U), 17 collegiate female rowers (C), and 21 elite oarswomen (E). Minute ventilation (VE) and frequency of respiration (fR) were examined on a log scale as their relationship with oxygen consumption (VO2) was exponential. The slopes for log VE/VO2 were similar for collegiate (0.65 +/- 0.02) and elite (0.59 +/- 0.01) rowers, but the slope was significantly higher for the untrained (0.87 +/- 0.01) subjects (P less than 0.001). Elite rowers utilized a higher tidal volume (VT) response per VO2 (0.68 +/- 0.04 vs 0.30 +/- 0.05; P = 0.01) and lower log fR response per VO2 (0.27 +/- 0.02 vs 0.50 +/- 0.03; P = 0.01) compared with collegiate rowers. The ratio of fR/strokes per minute (SPM) averaged 1.5 in E athletes but varied in the U and C groups. In the second part of the study, pattern and timing of respiration were recording using an inspiratory pneumotachygraph, analyzed, and compared with specific phases of the rowing stroke in ten untrained subjects and nine elite rowers. The ratio of inspiratory time (T1)/total respiratory time (TTOT) decreased during the drive phase and increased during the recovery phase in both untrained subjects and elite rowers.(ABSTRACT TRUNCATED AT 250 WORDS)
Article
The present study investigates the differential effectiveness of three treatment packages for agoraphobia. Patients suffering from panic disorder with agoraphobia (DSM-III-R) received one of three treatments: Breathing Retraining with Cognitive Restructuring (BRCR), graded self-exposure in vivo (EXP), or a combination of BRCR and EXP. Treatments consisted of 8 sessions. Assessment consisted of self-report measures for panic, phobic anxiety and avoidance, depression, general anxiety, somatic complaints and fear of body sensations, and of two respiratory measures (respiratory rate and alveolar pCO2). The treatments resulted in a reduction in symptomatology on all self-report measures, except panic frequency, and in a decrease in respiratory rate. There was no evidence for a differential efficacy for any of the treatments on any of the variables. Contrary to expectation, and at odds with findings from earlier studies, BRCR had no significant effect on panic frequency. A detailed comparison of sample characteristics of patients in our study and previous studies, did not yield insight into possible causes for the failure to replicate earlier results. The limited effectiveness of breathing retraining in reducing panic, as observed in the present study, leads us to conclude that the role of hyperventilation in panic is less important than previously thought.
Article
Respiratory muscle weakness can result from a variety of neuromuscular disorders, and it is now possible to identify different patterns of weakness and quantify the extent of this weakness using reliable, sensitive tests of respiratory muscle strength. However the quantification of respiratory muscle 'fatigue' has proved more difficult, and it is now recognized that there is unlikely to be one single index of fatigue, rather a whole sequence of changes that occur in response to loading. It is likely that in practice, a close interplay between respiratory pump capacity, demands on the pump and more especially, adaptive changes in respiratory drive, protect the respiratory muscles from overt peripheral contractile failure, and that the fall in tension following prolonged muscular activity involves many different closely inter-related processes. Investigation of these processes is likely to be more rewarding than attempts to develop a single 'test of fatigue', and may lead to an improved understanding of the role of respiratory muscle dysfunction in ventilatory failure.
Article
Because the inspiratory rib cage muscles are recruited during inspiratory resistive loaded breathing, we hypothesized that such loading would preferentially fatigue the rib cage muscles. We measured the pressure developed by the inspiratory rib cage muscles during maximal static inspiratory maneuvers (Pinsp) and the pressure developed by the diaphragm during maximal static open-glottis expulsive maneuvers (Pdimax) in four human subjects, both before and after fatigue induced by an inspiratory resistive loaded breathing task. Tasks consisted of maintaining a target esophageal pressure, breathing frequency, and duty cycle for 3-5 min, after which the subjects maintained the highest esophageal pressure possible for an additional 5 min. After loading, Pinsp decreased in all subjects [control, -128 +/- 14 (SD) cmH2O; with fatigue, -102 +/- 18 cmH2O; P less than 0.001, paired t test]. Pdimax was unchanged (control, -192 +/- 23 cmH2O; fatigue, -195 +/- 27 cmH2O). These data suggest that 1) inability to sustain the target during loading resulted from fatigue of the inspiratory rib cage muscles, not diaphragm, and 2) simultaneous measurement of Pinsp and Pdimax may be useful in partitioning muscle fatigue into rib cage and diaphragmatic components.
Article
To assess the effect of the normal respiratory resistive load on ventilation (VE) and respiratory motor output during exercise, we studied the effect of flow-proportional pressure assist (PA) (2.2 cmH2O.l-1.s) on various ventilatory parameters during progressive exercise to maximum in six healthy young men. We also measured dynamic lung compliance (Cdyn) and lung resistance (RL) and calculated the time course of respiratory muscle pressure (Pmus) during the breath in the assisted and unassisted states at a sustained exercise level corresponding to 70-80% of the subject's maximum O2 consumption. Unlike helium breathing, resistive PA had no effect on VE or any of its subdivisions partly as the result of an offsetting increase in RL (0.78 cmH2O.1-1.s) and partly to a reduction in Pmus. These results indicate that the normal resistive load does not constrain ventilation during heavy exercise. Furthermore, the increase in exercise ventilation observed with helium breathing, which is associated with much smaller degrees of resistive unloading (ca. -0.6 cmH2O.l-1.s), is likely the result of factors other than respiratory muscle unloading. The pattern of Pmus during exercise with and without unloading indicates that the use of P0.1 as an index of respiratory motor output under these conditions may result in misleading conclusions.
Article
Immersion of 18 male subjects in water caused a 20.4% (787 ml) increase (P less than 0.05) in the mean inspiratory capacity (IC) whereas there were no changes (P greater than 0.05) in tidal volume (VT) and the frequency of respiration. All the means for the other pulmonary variables decreased (P less than 0.05) by varying amounts: total lung capacity (TLC) = 8.4% (599 ml), vital capacity (VC) = 5.5% (308 ml), functional residual capacity (FRC) = 42.6% (1386 ml), expiratory reserve volume (ERV) = 61.9% (1095 ml) and residual volume (RV) = 19.7% (292 ml). Variation of only the RV in the body density (BD) formula from which the percentage body fat (%BF) is estimated resulted in a significantly (P less than 0.05) lower mean of 15.2% BF for the RV in air (means = 1482 ml) compared with that of 17.1% BF for the RV in water (means = 1190 ml). All but one of the subjects exhibited a smaller RV in water than in air; the six largest differences were equivalent to 2.4-5.1% BF. These results indicate that the net effect of the hydrostatic pressure (decreases RV), pulmonary vascular engorgement (decreases RV) and diminished compliance (increases RV) is to reduce the ventilated RV. It is therefore advisable to measure the RV when the subject is immersed in order to minimize error in the determination of BD and hence the estimation of % BF.
Article
1. The intensity of breathlessness during exercise was measured in ten normal subjects using a visual analogue scale (VAS) and a Borg scale to compare the use of the scales and their repeatability, both within the duration of a period of exercise and between tests. For each scale, subjects performed two exercise tests separated by a period of 2–6 weeks. Each exercise test consisted of two cycles of progressively increasing and decreasing workload. 2. All subjects felt confidently able to use both scales to quantify their feelings of breathlessness exclusively of other sensation. Equal preference was expressed for use of a particular scale. 3. With both scales there was a large intersubject variation in the relationship between dyspnoea score and minute ventilation (VE) (P < 0.01), and in the range of the scale used. 4. There was a good correlation between the VAS and Borg scores at each level of VE (r2 = 0.71), but the VAS score was used over a wider range than the Borg score. 5. The relationship between VE and the dyspnoea score measured by the two techniques was predominantly linear. The mean r2 for VAS score/VE was 0.68 (sd 0.19) and for Borg score/VE the mean r2 was 0.75 (sd 0.13). 6. The relationships VAS score/VE and Borg score/VE were unaffected by the direction in which the workload was varied (P > 0.05). 7. VE, measured at each work rate, did not differ between the two cycles (P > 0.05) or between the 2 days (P > 0.05). 8. With both scales, the slope of the VE-breathlessness relationship was slightly higher during the second half of the exercise compared with the first (0.05 < P > 0.01). 9. The scores with both scales were lower in the second test compared with the first (P < 0.01): Borg 16% lower, VAS 27% lower. 10. Measurements of dyspnoea made with the Borg scale appeared to have greater stability than VAS measurements and to correlate with VE a little better.
Article
We hypothesized that during maximal respiratory efforts involving the simultaneous activation of two or more chest wall muscles (or muscle groups), differences in muscle strength require that the activity of the stronger muscle be submaximal to prevent changes in thoracoabdominal configuration. Furthermore we predicted that maximal respiratory pressures are limited by the strength of the weaker muscle involved. To test these hypotheses, we measured the pleural pressure, abdominal pressure (Pab), and transdiaphragmatic pressure (Pdi) generated during maximal inspiratory, open-glottis and closed-glottis expulsive, and combined inspiratory and expulsive maneuvers in four adults. We then determined the activation of the diaphragm and abdominal muscles during selected maximal respiratory maneuvers, using electromyography and phrenic nerve stimulation. In all subjects, the Pdi generated during maximal inspiratory efforts was significantly lower than the Pdi generated during open-glottis expulsive or combined efforts, suggesting that rib cage, not diaphragm, strength limits maximal inspiratory pressure. Similarly, at high lung volumes, the Pab generated during closed-glottis expulsive efforts was significantly greater than that generated during open-glottis efforts, suggesting that the latter pressure is limited by diaphragm, not abdominal muscle, strength. As predicted, diaphragm activation was submaximal during maximal inspiratory efforts, and abdominal muscle activation was submaximal during open-glottis expulsive efforts at midlung volume. Additionally, assisting the inspiratory muscles of the rib cage with negative body-surface pressure significantly increased maximal inspiratory pressure, whereas loading the rib cage muscles with rib cage compression decreased maximal inspiratory pressure. We conclude that activation of the chest wall muscles during static respiratory efforts is determined by the relative strengths and mechanical advantage of the muscles involved.
Article
During progressive exercise ventilation (VI) initially increases through increases in both tidal volume (VT) and respiratory frequency (f) but at high levels of exercise further increases in VI are almost completely due to increases in f and a VT plateau is seen. We wished to determine whether the presence of the VT plateau is due to a tachypneic influence related to very high levels of exercise or whether it represents a stereotypic response of the respiratory system at high levels of VI. We therefore compared breathing pattern in six subjects during maximal incremental exercise (ME) with that in the same subjects when similar levels of VI were obtained by a combination of submaximal exercise and hypercapnia (E/CO2). A VT plateau was seen in all ME and E/CO2 tests. There was no significant difference in the level of the VT plateau between the ME (2.93 +/- 0.17 liters) and E/CO2 (2.97 +/- 0.12 liters) tests. We conclude that the presence and level of the VT plateau during ME is not due to a tachypneic stimulus related to very high levels of exercise but is a function of the level of VI.
Article
We have examined the relationship between respiratory effort sensation (modified Borg scale) and amplitude of the integrated surface electromyogram of the diaphragm (Edi, esophageal electrode), rib cage muscles (Erc), and sternomastoid muscle (Esm) during the development of diaphragm fatigue in five normal subjects. Three conditions were studied: run A: transdiaphragmatic pressure (Pdi), 65% Pdimax; esophageal pressure (Pes), 60% Pesmax; run B: Pdi, 50% Pdimax; Pes, 60% Pesmax; and run C: Pdi, 50% Pdimax; Pes, 20% Pesmax. During all runs there was a progressive rise in sensation, which was greater in runs A and B than in run C (P less than 0.05, analysis of variance). There was no difference between runs A and B. At the end of run C subjects did not report a maximal Borg score despite their inability to generate the target Pdi. The increase in sensory score with fatigue correlated highly with Esm/Esmmax and with Erc/Ercmax. There was no correlation between sensory score and Edi/Edimax. We conclude that the increase in respiratory effort sensation that accompanies diaphragm fatigue is not due to perception of increased diaphragmatic activation. It may reflect increased overall respiratory motor output not directed to the diaphragm.