An optimal and feedback control routines were developed in this thesis to control simulations of a respiratory system with a muscle and lung compartments. The optimal model was used to find the alveolar ventilation and the Van der Pol constants (𝛼, 𝜔, and 𝛆) that could be used in the body during the steady-state of exercise for each workload. Then, the feedback control model was used to simulate the transient exercise states. The alveolar ventilation was calculated in the feedback control model using a proportional (mean) and a derivative (rate) control. Then, the Van der Pol constants were found from the alveolar ventilation found in the optimal routine. In addition, simulations were done in the steady-state for 3 %, 5 %, and 6 % carbon dioxide inhalation. Once the controller constants had been found, the transient-state of the feedback model showed great promise as the partial pressure of arterial carbon dioxide did not become more than 3.8 % greater then the value that is maintained in the body. The carbon dioxide inhalation tests came within 3 % of the experimental values given by Reynolds (1972). The results from this thesis show that using a Van der Pol oscillator as the breather in the model seems to keep the partial pressure of arterial CO₂ around the value that is maintained in the body for aerobic exercise and CO₂ inhalation. / Master of Science

As the world begins to focus more and more on new and more effective means of energy production, fuel cells become increasingly more popular. While different fuel cells are already found in industry today, the direct methanol fuel cell (DMFC) is becoming an increasingly more probable means for portable power production. In such applications a passive air breathing direct methanol fuel cell would be ideal. However, successful use of the passive DMFC in such applications requires that the fuel cell be capable of operating at various temperatures and relative humidities. A passive air breathing direct methanol fuel cell was developed and manufactured for this study. This work studied the effects of varying relative humidity and temperature over a probable range of operating conditions for small scale portable power applications on the performance of the fuel cell, both in relation to power production and fuel consumption. Potentiostatic, electrochemical impedance spectroscopy, and polarization tests were performed in order to characterize the performance of the fuel cell. Additionally, a one dimensional steady state isothermal mass transport model was developed to provide insight to the behavior of the fuel cell. The experimental data and model results show that increasing the fuel cell temperature and decreasing the ambient relative humidity increases the current production capabilities of the fuel cell. Further, the experimental data suggests that the major problem hindering current production in passive air breathing direct methanol fuel cells is flooding of the cathode diffusion layer. / Master of Science

Design and development of future high speed aircraft require the use of advanced modeling tools early on in the design phase to study and analyze complex aeroelastic, thermoelastic, and aerothermal interactions. This phase, commonly referred to as the conceptual design phase, involves using first principle based analytical models to obtain a practical starting point for the preliminary and detailed design phases. These analytical models are expected to, firstly, capture the effect of complex interactions between various subsystems using basic physics, and secondly, minimize computational costs. The size of a typical air-breathing hypersonic vehicle can vary anywhere between 12 ft, like the NASA X-43A, to 100 ft, like the NASP demonstrator vehicle. On the other hand, the performance expectations can vary anywhere between cruising at Mach 5 @ 85; 000 ft to Mach 10 @ 110; 000 ft. Reduction of computational costs is essential to efficiently sort through such a vast design space, while capturing the various complex interactions between subsystems has shown to improve accuracy of the design estimates. This motivates the need to develop modelling tools using first principle based analytical models with "needed" fidelity, where fidelity refers to the extent of interactions captured. With the advent of multidisciplinary design optimization tools, the need for an integrated modelling and analysis environment for high speed aircraft has increased substantially over the past two decades. The ever growing increase in performance expectations has made the traditional design approach of optimize first, integrate later obsolete. Designing a closed-loop control system for an aircraft might prove to be a difficult task with a geometry that yields an optimal (L/D) ratio, a structure with optimal material properties, and a propulsion system with maximum thrust-weight ratio. With all the subsystems already optimized, there is very little freedom for control designers to achieve their high performance goals. Integrated design methodologies focus on optimizing the overall design, as opposed to individual subsystems. Control-oriented modelling is an approach that involves making appropriate assumptions while modelling various subsystems in order to facilitate the inclusion of control design during the conceptual design phase. Due to their high lift-to-drag ratio and low operational costs, air-breathing hypersonic vehicles have spurred some interest in the field of high speed aircraft design over the last few decades. Modeling aeroelastic effects for such an aircraft is challenging due to its tightly integrated airframe and propulsion system that leads to significant deflections in the thrust vector caused by flexing of the airframe under extreme aerodynamic and thermal loads. These changes in the orientation of the thrust vector in turn introduce low frequency oscillations in the flight path angle, which make control system design a challenging task. Inclusion of such effects in the vehicle dynamics model to develop accurate control laws is an important part of control-oriented modeling. The air-breathing hypersonic vehicle considered here is assumed to be a thin-walled structure, where deformations due to axial, bending, shear, and torsion are modeled using the six independent displacements of a rigid cross section. Free vibration mode shapes are computed accurately using a novel scheme that uses estimates of natural frequency from the Ritz method as initial guesses to solve the governing equations using SUPORE, a two-point boundary value problem solver. A variational approach involving Hamilton's principle of least action is employed to derive the second order nonlinear equations of motion for the flexible aircraft. These nonlinear equations of motion are then linearized about a given cruise condition, modal analysis carried out on the linearized system, and the coupling between various significant modes studied. Further, open-loop stability analysis in time domain is conducted. / Ph. D.

The annual hydrological cycle of floodplains supports fishes that are uniquely adapted to optimize resources throughout the year. Such adaptations to changing environments include air-breathing for seasonally hypoxic waters and directed movements to best utilize habitats as they become available. This study examined the environmental, temporal and body-size influences on air-breathing behavior and movement ecology of Arapaima sp., one of the most economically and ecologically significant species in the Amazon. Acoustic (n=15) and radio (n=12) telemetry was used to study the influences on air-breathing and movement ecology of arapaima in the Central Amazon. Generalized additive mixed models showed that temperature was the most influential predictor of air-breathing intervals, followed by body size. The shortest breathing intervals were associated with consecutive "aggressive" breaths while the longest breathing intervals had consecutive "calm" breaths. Generalized linear mixed models showed that flood stage was the most important predictor of residency time, directional movement, and rate of movement. Fish moved faster in the flood and dry stages than the rising and falling stages, and spent longer in one place in the rising and falling stages than the flood and dry stages. Findings of this study may be used to inform management decisions for arapaima conservation, such as protected habitat and population counts, with applications to fishes across river-floodplain ecosystems globally. / Master of Science

Every architecure is being with life-force such as a plant who lives on the photosynthesis that need carbon dioxide + water + light energy, and provide oxygen in day time. On the contrary, Plants need oxygen and release carbon dioxide while they can not carry out the photosunthesis in night time. But both chemical reactions occurring on the same plant in different time in a day. People normally spend one-third of their for working in an office or studying in school, and their home is empty during the day time. People use the rest of their time on a dinner in restaurant outside, other activities or events; back to home to rest and nobody occupies commercial area in night time. Why can we not do all of life's events in the same building or place whenever we wish? / Master of Architecture

Introdução: A respiração oronasal pode impactar adversamente em pacientes com apneia obstrutiva do sono (AOS) pelo aumento da colapsabilidade da via aérea piorando as apneias ou por influenciar os desfechos de tratamento com a pressão positiva continua de vias aéreas (CPAP). Embora os autorrelatos de respiração oronasal sejam comumente utilizados como uma evidência para prescrição da CPAP oronasal, a associação entre o autorrelato e a mensuração objetiva da via preferencial de respiração ainda é desconhecida. Nós hipotetizamos que a respiração oronasal objetivamente mensurada seja mais comum em pacientes com AOS do que em controles, mas que não esteja associada com o autorrelato de respiração oronasal. Os objetivos do presente estudo foram, portanto, determinar: (1) a via preferencial de respiração em controles e pacientes com AOS na vigília e no sono, (2) a concordância entre a via preferencial de respiração mensurada objetivamente e a via preferencial de respiração autorrelatada, e (3) a associação entre a via preferencial de respiração mensurada objetivamente e os sintomas nasais e fatores em pacientes com AOS. Casuística e Método: Foram incluídos 26 indivíduos não tabagistas recrutados na FMUSP (funcionários) e no Ambulatório de Sono do InCor-HCFMUSP (indivíduos com suspeita de AOS). Para o diagnóstico de AOS os indivíduos foram submetidos a uma polissonografia (PSG). A AOS foi definida como índice de apneia-hipopneia (IAH) >= 15 eventos/hora e determinou a alocação dos indivíduos em dois grupos: grupo controle [idade: 40±10 anos, 4 (44%) homens, índice de massa corpórea (IMC): 25±5 kg/m2, IAH: 5±4 eventos/hora] e grupo AOS (idade: 52±14 anos, 10 (59%) homens, IMC: 31±5 kg/m2, IAH: 56 ± 21 eventos/hora). Para avaliar a via preferencial de respiração (nasal ou oronasal) os indivíduos foram submetidos a uma segunda PSG com uso de uma máscara com 2 compartimentos selados (nasal e oral) e conectados a pneumotacógrafos independentes. A via de respiração preferencial foi determinada durante a vígilia que antecedeu o início de sono e durante o sono. Avaliamos dados clínicos e de função pulmonar. Os indivíduos responderam a questionários sobre a percepção da sua via preferencial de respiração, os sintomas nasais (SNOT-20), a sonolência diurna excessiva (Epworth) e a qualidade do sono (Pittsburgh). Resultados: O grupo controle e AOS foram similares no sexo, co-morbidades e uso de medicamentos. Pacientes com AOS eram mais velhos, tinham maior IMC, pressão arterial sistêmica e circunferência do pescoço. A via preferencial de respiração foi similar na vigília e sono. Observamos que os respiradores oronasais foram mais frequentes nos pacientes com AOS se comparados aos controles (65-71% e 0-22%, respectivamente, p < 0,001). Os controles e pacientes com AOS autorrelataram respiração oronasal em 22% e 59% dos casos, respectivamente (p = 0,110). Entretanto, encontramos pobre concordância entre o autorrelato da via de respiração e a via de respiração identificada no grupo controle (Kappa = 0,36) e nenhum concordância nos pacientes com AOS (Kappa = -0,02). Não houve associação entre os sintomas nasais e a respiração oronasal quando considerados todos os indivíduos do estudo (p = ,267). A respiração oronasal foi associada ao aumento do IAH (r = 0,409 e p = 0,038), aumento da idade (r = 0,597 e p = 0,001) e aumento da circunferência do pescoço (r = 0,464 e p = 0,017). Além disso, mudanças na via de respiração após apneias obstrutivas foram incomuns. Conclusões: Em contraste com os controles, os pacientes com AOS sãos frequentemente respiradores oronasais. Contudo, a auto-percepção da via de respiração e de sintomas nasais não prediz medidas objetivas da via preferencial de respiração. Além disso, a respiração oronasal é associada à gravidade da AOS, ao aumento da idade e da circunferência do pescoço / Background: Oronasal breathing may adversely impact obstructive sleep apnea (OSA) patients either by increasing upper airway collapsibility or by influencing CPAP treatment outcomes. Although self-reported oronasal breathing is commonly used as evidence for oronasal CPAP prescription, the association between self-reported and objectively measured preferential breathing route is unknown. We hypothesized that objectively measured oronasal breathing is more common in OSA patients than in controls but is not associated with self-reported breathing route. The aims of this study were, therefore, to determine (1) the preferential breathing route in controls and OSA patients, (2) the agreements between objective analysis of breathing route and self-reports, and (3) the associations between preferential breathing route objectively measure and nasal symptoms and factors in OSA patients. Methods: We included 26 non-smokers enrolled at FMUSP (employees) and Sleep Laboratory at InCor-HCFMUSP (individuals with suspected AOS). For the diagnosis of OSA, the subjects were submitted a full polysomnography (PSG). OSA was defined as apnea-hypopnea index (AHI) >= 15 events/hour and determined the allocation of individuals in two groups: Control group [age: 40 ± 10 years, 4 (44%) men, body mass index (BMI): 25±5 kg/m2, AHI: 5 ± 4 events / hour] and OSA group (age: 52 ± 14 years, 10 (59%) men, BMI: 31±5 kg/m2, mean AHI: 56 ± 21 events / hour). To evaluate the preferential breathing route (nasal or oronasal) the subjects underwent a second overnight PSG with oronasal mask with 2 sealed compartments attached to independent pneumotacographs. The preferential breathing route was determined during wakefulness before sleep and during sleep. We evaluated clinical data and lung function. Subjects answered questionnaires about perceived preferential breathing route, nasal symptoms questionnaires (SNOT-20), excessive daytime sleepiness (Epworth) and sleep quality (Pittsburgh). Results: Controls and OSA patients were similar in sex, co-morbidities and use of medications. OSA patients were older, had higher BMI and blood pressure as larger neck circumference. Breathing pattern awake and asleep was similar. Compare to controls, oronasal breathers was more frequent in OSA patients (0-22% and 65-71%, respectively, p < 0.001). Controls and OSA patients self-reported oronasal breathing in 22% and 59% of cases, respectively (p = 0.110). There were poor agreements between self-reports and objective analysis in controls (Kappa = 0.36) and no agreement in OSA patients (Kappa = -0.02). No associations were found between nasal symptoms and oronasal breathing when all subjects were considered (p = 0.267). Oronasal breathing was associated with OSA severity (r = 0.409 and p = 0.038), increasing age (r = 0.597 and p = 0.001) and higher neck circumference (r = 0.464 and p = 0.017). Additionally, the changes of breathing route were uncommon during obstructive apneas. Conclusions: In contrast to controls, OSA patients are preferentially oronasal breathers. However, self-perception does not predict objectively measured preferential breathing route. Oronasal breathing is associated with OSA severity, increasing age and higher neck circumference

Introdução: A respiração oronasal pode impactar adversamente em pacientes com apneia obstrutiva do sono (AOS) pelo aumento da colapsabilidade da via aérea piorando as apneias ou por influenciar os desfechos de tratamento com a pressão positiva continua de vias aéreas (CPAP). Embora os autorrelatos de respiração oronasal sejam comumente utilizados como uma evidência para prescrição da CPAP oronasal, a associação entre o autorrelato e a mensuração objetiva da via preferencial de respiração ainda é desconhecida. Nós hipotetizamos que a respiração oronasal objetivamente mensurada seja mais comum em pacientes com AOS do que em controles, mas que não esteja associada com o autorrelato de respiração oronasal. Os objetivos do presente estudo foram, portanto, determinar: (1) a via preferencial de respiração em controles e pacientes com AOS na vigília e no sono, (2) a concordância entre a via preferencial de respiração mensurada objetivamente e a via preferencial de respiração autorrelatada, e (3) a associação entre a via preferencial de respiração mensurada objetivamente e os sintomas nasais e fatores em pacientes com AOS. Casuística e Método: Foram incluídos 26 indivíduos não tabagistas recrutados na FMUSP (funcionários) e no Ambulatório de Sono do InCor-HCFMUSP (indivíduos com suspeita de AOS). Para o diagnóstico de AOS os indivíduos foram submetidos a uma polissonografia (PSG). A AOS foi definida como índice de apneia-hipopneia (IAH) >= 15 eventos/hora e determinou a alocação dos indivíduos em dois grupos: grupo controle [idade: 40±10 anos, 4 (44%) homens, índice de massa corpórea (IMC): 25±5 kg/m2, IAH: 5±4 eventos/hora] e grupo AOS (idade: 52±14 anos, 10 (59%) homens, IMC: 31±5 kg/m2, IAH: 56 ± 21 eventos/hora). Para avaliar a via preferencial de respiração (nasal ou oronasal) os indivíduos foram submetidos a uma segunda PSG com uso de uma máscara com 2 compartimentos selados (nasal e oral) e conectados a pneumotacógrafos independentes. A via de respiração preferencial foi determinada durante a vígilia que antecedeu o início de sono e durante o sono. Avaliamos dados clínicos e de função pulmonar. Os indivíduos responderam a questionários sobre a percepção da sua via preferencial de respiração, os sintomas nasais (SNOT-20), a sonolência diurna excessiva (Epworth) e a qualidade do sono (Pittsburgh). Resultados: O grupo controle e AOS foram similares no sexo, co-morbidades e uso de medicamentos. Pacientes com AOS eram mais velhos, tinham maior IMC, pressão arterial sistêmica e circunferência do pescoço. A via preferencial de respiração foi similar na vigília e sono. Observamos que os respiradores oronasais foram mais frequentes nos pacientes com AOS se comparados aos controles (65-71% e 0-22%, respectivamente, p < 0,001). Os controles e pacientes com AOS autorrelataram respiração oronasal em 22% e 59% dos casos, respectivamente (p = 0,110). Entretanto, encontramos pobre concordância entre o autorrelato da via de respiração e a via de respiração identificada no grupo controle (Kappa = 0,36) e nenhum concordância nos pacientes com AOS (Kappa = -0,02). Não houve associação entre os sintomas nasais e a respiração oronasal quando considerados todos os indivíduos do estudo (p = ,267). A respiração oronasal foi associada ao aumento do IAH (r = 0,409 e p = 0,038), aumento da idade (r = 0,597 e p = 0,001) e aumento da circunferência do pescoço (r = 0,464 e p = 0,017). Além disso, mudanças na via de respiração após apneias obstrutivas foram incomuns. Conclusões: Em contraste com os controles, os pacientes com AOS sãos frequentemente respiradores oronasais. Contudo, a auto-percepção da via de respiração e de sintomas nasais não prediz medidas objetivas da via preferencial de respiração. Além disso, a respiração oronasal é associada à gravidade da AOS, ao aumento da idade e da circunferência do pescoço / Background: Oronasal breathing may adversely impact obstructive sleep apnea (OSA) patients either by increasing upper airway collapsibility or by influencing CPAP treatment outcomes. Although self-reported oronasal breathing is commonly used as evidence for oronasal CPAP prescription, the association between self-reported and objectively measured preferential breathing route is unknown. We hypothesized that objectively measured oronasal breathing is more common in OSA patients than in controls but is not associated with self-reported breathing route. The aims of this study were, therefore, to determine (1) the preferential breathing route in controls and OSA patients, (2) the agreements between objective analysis of breathing route and self-reports, and (3) the associations between preferential breathing route objectively measure and nasal symptoms and factors in OSA patients. Methods: We included 26 non-smokers enrolled at FMUSP (employees) and Sleep Laboratory at InCor-HCFMUSP (individuals with suspected AOS). For the diagnosis of OSA, the subjects were submitted a full polysomnography (PSG). OSA was defined as apnea-hypopnea index (AHI) >= 15 events/hour and determined the allocation of individuals in two groups: Control group [age: 40 ± 10 years, 4 (44%) men, body mass index (BMI): 25±5 kg/m2, AHI: 5 ± 4 events / hour] and OSA group (age: 52 ± 14 years, 10 (59%) men, BMI: 31±5 kg/m2, mean AHI: 56 ± 21 events / hour). To evaluate the preferential breathing route (nasal or oronasal) the subjects underwent a second overnight PSG with oronasal mask with 2 sealed compartments attached to independent pneumotacographs. The preferential breathing route was determined during wakefulness before sleep and during sleep. We evaluated clinical data and lung function. Subjects answered questionnaires about perceived preferential breathing route, nasal symptoms questionnaires (SNOT-20), excessive daytime sleepiness (Epworth) and sleep quality (Pittsburgh). Results: Controls and OSA patients were similar in sex, co-morbidities and use of medications. OSA patients were older, had higher BMI and blood pressure as larger neck circumference. Breathing pattern awake and asleep was similar. Compare to controls, oronasal breathers was more frequent in OSA patients (0-22% and 65-71%, respectively, p < 0.001). Controls and OSA patients self-reported oronasal breathing in 22% and 59% of cases, respectively (p = 0.110). There were poor agreements between self-reports and objective analysis in controls (Kappa = 0.36) and no agreement in OSA patients (Kappa = -0.02). No associations were found between nasal symptoms and oronasal breathing when all subjects were considered (p = 0.267). Oronasal breathing was associated with OSA severity (r = 0.409 and p = 0.038), increasing age (r = 0.597 and p = 0.001) and higher neck circumference (r = 0.464 and p = 0.017). Additionally, the changes of breathing route were uncommon during obstructive apneas. Conclusions: In contrast to controls, OSA patients are preferentially oronasal breathers. However, self-perception does not predict objectively measured preferential breathing route. Oronasal breathing is associated with OSA severity, increasing age and higher neck circumference

Background: Breathing exercises are widely used after cardiac surgery. The duration of exercises in the immediate postoperative period is not fully evaluated and only limited data regarding the effects of home-based breathing exercises after discharge from hospital have been published. Aim: The overall aim of this thesis was to evaluate the effects of deep breathing exercises with positive expiratory pressure (PEP) and describe lung function and respiratory muscle strength in patients undergoing cardiac surgery. Participants and settings: Adult participants (n=131) were randomised to perform either 30 or 10 deep breaths with PEP per hour during the first postoperative days (Study I): the main outcome was oxygenation, assessed by arterial blood gases, on the second postoperative day. In Study III, 313 adult participants were randomly assigned to perform home-based deep breathing exercises with PEP for two months after surgery or not to perform breathing exercises with PEP after the fourth to fifth postoperative day. The main outcome was lung function, assessed by spirometry, two months after surgery. Studies II and IV were descriptive and correlative and investigated pre and postoperative lung function, assessed by spirometry, and respiratory muscle strength, assessed by maximal inspiratory pressure, and maximal expiratory pressure. Results: On the second postoperative day, arterial oxygen tension (PaO2) and arterial oxygen saturation (SaO2) was higher in the group randomised to 30 deep breaths with PEP hourly. There was no improved recovery of lung function in participants performing home-based deep breathing exercises two months after cardiac surgery, compared to a control group. Subjective experience of breathing or improvement in patient perceived quality of recovery or health-related quality of life did not differ between the groups at two months. Lung function and respiratory muscle strength were in accordance with predicted values before surgery. A 50% reduction in lung function was shown on the second postoperative day. High body mass index, male gender and sternal pain were associated with decreased lung function on the second postoperative day. Two months postoperatively, there was decreased lung function, but respiratory muscle strength had almost recovered to preoperative values. / <p></p><p></p>

The main task of this thesis was an examination of breathing stereotypes on selected students of Pedagogical faculty aged from 19 to 25. The other objective was to develop an intervention programme according to which the selected students participated in six weeks lasting workouts that were focused on breath training with consecutive heightening of their physical efficiency. A method of content analysis was used for analysing literature and a method of content synthesis was used for application of gathered information and for creating the intervention programme. For the examination of breathing stereotypes a muscle dynamometer was used which is able to record a movement dynamics and simultaneously to record a breathing activity dynamics. The vital capacity was measured through a forced expiratory vital capacity (FVC) when also a value of one second exhale was recorded (FEV1). This test was performed in standing upright position on the machine Spirometr Otthon, evaluation was processed in the Thorsoft programme. The study was participated by six students who at first passed out an entrance examination where the main values were defined, then the intervention programme and after the end of it the participants underwent a checking (output) examination. During processing of the thesis it was confirmed that the developed intervention programme, which is based on aerobic exercises and completed with resistance training, has a factual and statistical significant effect on strengthening the respiratory muscles which are activated by the diaphragmatic breathing within resting breathing and deepened breathing. For the determination of the substantive significance the Cohen's d was used, then the paired Student´s t test for dependent samples.

Die Schwimmer des Deutschen Schwimmverbands verlieren zunehmend den Anschluss an die Weltspitze, was sich in einer sinkenden Anzahl von Medaillen bei internationalen Großereignissen äußert. Als Ursache wurden Mängel im langfristigen Leistungsaufbau identifiziert; in Folge dessen wurden spezifischere Inhalte für das Grundlagenausdauertraining gefordert, um die wettkampfspezifischen Kraftvoraussetzungen besser vorzubereiten. Da gezeigt werden konnte, dass die Atmung im Freistilschwimmen leistungsbegrenzend wirkt, sollte untersucht werden, wie sich durch ein gezieltes Training der Atemmuskulatur bislang ungenutzte Leistungsreserven erschließen lassen. Darüber hinaus sollte die Reaktion auf Hypoventilation unter Belastung getestet werden, da eine Analyse der Atemrhythmen international erfolgreicher Schwimmer ergeben hatte, dass sich niederfrequente Atmung im Wettkampf vorteilhaft auf die Leistung auswirkt. Dazu wurde eine Interventionsstudie mit 15 Nachwuchsschwimmern im Crossover-Design durchgeführt. Während des ersten und des zweiten Makrozyklus des Trainings- und Wettkampfjahres (TWJ) führten je sechs Sportler ein achtwöchiges Atemtraining mit einem POWERbreathe-Gerät durch. Zur Quantifizierung der Leistungsfähigkeit und der Veränderung physiologischer Parameter durch Training wurden vor und nach jeder Intervention Stufentests im Strömungskanal durchgeführt, wobei drei verschiedene Intensitäten und zwei Atemfrequenzen ausgewertet wurden. Das Hauptergebnis der Studie bestand in einer verbesserten Kraftfähigkeit und Ökonomie der Atemmuskulatur, was sich bei isolierter Belastung in Form einer Vergrößerung des maximalen Minutenvolumens zeigte und beim Schwimmen zu verringerten Laktatwerten und niedrigerer Zyklusfrequenz bei gleichbleibender Belastung führte. Die Trainingswirkung wird dabei auf eine weniger starke Ausprägung des inspiratorischen Metaboreflexes und eine Optimierung der Vortriebsphasen in Folge einer schnelleren Inspiration zurückgeführt. Durch das Atemtraining konnte die respiratorische Muskulatur in Trainingsphasen niedrigerer Intensität auf die höheren Belastungen im späteren Verlauf des TWJ vorbereitet werden. Der Einsatz eines solchen Trainings hat daher das Potential, die Leistungsfähigkeit von Freistilschwimmern zu steigern.:Einleitung Theoriepositionen: Anforderungen an die Atmung im Schwimmen Bewegungsstruktur und Atemverhalten im Wettkampf Atemphysiologie unter Belastung Atemtraining Forschungsdefizit Fragestellung Methoden: Arbeitsschwerpunkte und Lösungsweg Pilotstudie im Strömungskanal Hauptuntersuchung Methodenkritik Ergebnisse: Ergebnisse der Voruntersuchungen Auswertung des Atemtrainings Leistungsphysiologische Veränderungen durch Training Einfluss der Intensität auf leistungsphysiologische Parameter Einfluss der Atemfrequenz auf leistungsphysiologische Parameter Zusammenhänge zwischen leistungsphysiologischen Parametern und den Ergebnissen des POWERbreathe-Trainings Diskussion: Wirkung eines lokalen Krafttrainingsreizes auf die Atemmuskulatur und auf pulmonale Parameter Systemische Effekte eines Atemtrainings auf leistungsphysiologische Parameter Konsequenzen einer Atmungseinschränkung für die Energiebereitstellung Wirkung des Atemtrainings auf die Bewegungsstruktur Trainingswissenschaftliche Aspekte Fazit: Empfehlungen für die Durchführung eines Atemtrainings Zukünftige Fragestellungen Zusammenfassung und Ausblick / At present the athletes of the German swimming association are unable to keep up with the performance of the world’s leading swimmers. Thus, the number of medals achieved within international competitions decreases. Analyses could trace back this trend to deficits regarding the long-term athlete development. As a result, there are growing demands on increasing the specificity of the basic endurance training in terms of a more adequate preparation of race-specific strength capacities. Since studies showed that the efficiency of the respiratory system can limit exercise performance, the aim of this dissertation was to analyze the potential of a specific training of the breathing muscles to access reserve capacities in freestyle swimming. An evaluation of the breathing patterns of successful athletes showed that a low-frequency breathing pattern has a positive impact on freestyle performance, hence another goal of this study was to investigate the effect of hypoventilation during high intensity swimming. A crossover intervention study was conducted with 15 adolescent swimmers. During the first and the second macro cycle of the swimming season an eight week POWERbreathe training was performed by six swimmers each. Before and after each intervention incremental tests were conducted in a swimming flume to assess exercise capacity and the change of exercise physiological parameters in response to the training stimulus. Within this test protocol three graded exercise intensities and two different breathing frequencies were taken into account. The main result of the study was an improved strength and enhanced economy of the breathing muscles which resulted in an increased maximum voluntary ventilation (MVV), decreasing levels of lactate and lower cycle frequencies during freestyle swimming at a given velocity. The training effect is based on the attenuation of the inspiratory metaboreflex and optimization of the propulsion phases due to a more rapid inspiration. Because of the breathing training the respiratory muscles were exposed to a high training stimulus within low-intensity swimming training periods which resulted in an improved preparation of higher swimming intensities in the later stages of the swimming season. Thus, the POWERbreathe training has the potential to enhance exercise performance of freestyle swimmers.:Einleitung Theoriepositionen: Anforderungen an die Atmung im Schwimmen Bewegungsstruktur und Atemverhalten im Wettkampf Atemphysiologie unter Belastung Atemtraining Forschungsdefizit Fragestellung Methoden: Arbeitsschwerpunkte und Lösungsweg Pilotstudie im Strömungskanal Hauptuntersuchung Methodenkritik Ergebnisse: Ergebnisse der Voruntersuchungen Auswertung des Atemtrainings Leistungsphysiologische Veränderungen durch Training Einfluss der Intensität auf leistungsphysiologische Parameter Einfluss der Atemfrequenz auf leistungsphysiologische Parameter Zusammenhänge zwischen leistungsphysiologischen Parametern und den Ergebnissen des POWERbreathe-Trainings Diskussion: Wirkung eines lokalen Krafttrainingsreizes auf die Atemmuskulatur und auf pulmonale Parameter Systemische Effekte eines Atemtrainings auf leistungsphysiologische Parameter Konsequenzen einer Atmungseinschränkung für die Energiebereitstellung Wirkung des Atemtrainings auf die Bewegungsstruktur Trainingswissenschaftliche Aspekte Fazit: Empfehlungen für die Durchführung eines Atemtrainings Zukünftige Fragestellungen Zusammenfassung und Ausblick