Impacto del Entrenamiento Respiratorio de Hiperpnea Isocápnica Voluntaria sobre el Costo Energético asociado a la Respiración inducido por Ejercicio Físico / Impact of Voluntary Isocapnic Hyperpnea training on the cost of breathing

Introducción. Determinar el efecto de ocho semanas de entrenamiento por hiperpnea isocápnica voluntaria (HIV) sobre el costo energético asociado a la respiración (COB) reflejado en los cambios en la oxigenación de los músculos intercostales (∆SmO2-m. intercostales) inducida por ejercicio físico de intensidad incremental. Métodos. Doce participantes físicamente activos fueron entrenados durante ocho semanas de HIV 3 días x semana, 12 minutos, al 60% de ventilación voluntaria máxima (VVM). En la semana previa y posterior al entrenamiento HIV se realizó un test cardiopulmonar (CPET) de intensidad incremental en cicloergómetro, durante esta prueba se registró la ∆SmO2-m. intercostales mediante el dispositivo MOXY®. El efecto de HIV sobre la ∆SmO2-m. intercostales se analizó mediante la prueba two-way mixed ANOVA considerando los factores (fase × tarea). Resultados. ∆SmO2-m.intercostales fue significativamente menor a partir del 30% (­5,0±4,7%; p<0.01) hasta el 100% (­10,6±12,8%; p<0.01) de la tarea luego de ocho semanas de HIV. Además, se reportó un aumento de la presión inspiratoria máxima (PIM)=16,5±11,4 cmH2O (p<0.01); y de la resistencia muscular respiratoria=106,6±149,0 s (p<0.01). El tiempo total de ejercicio aumentó en 106,6±149,0 s (p=0.04), así como la carga total en 10,50± 10,12 vatios (p<0.01). Conclusión. El HIV disminuye el COB inducido por ejercicio incremental asociado a un incremento en la performance física y de los músculos respiratorios. En futuros estudios se sugiere estudiar esta estrategia de entrenamiento analítico de los músculos respiratorios en usuarios con limitación física relacionada al aumento prematuro del COB.

Background. Objetive. To determine the effect of eight weeks of voluntary isocapnic hyperpnea (VIH) training on cost of breathing (COB) as reflected by intercostales muscles deoxygenation (∆SmO2-m. intercostales) induced by incremental-intensity physical exercise. Methods. Twelve physically active participants underwent eight weeks of VIH training, three days a week, for 12 minutes each session, at 60% of maximal voluntary ventilation (MVV). In the week before and after VIH training, a cardiopulmonary test (CPET) of incremental intensity was performed on a cycloergometer. During this test, intercostal ∆SmO2-m.intercostales was recorded using the MOXY® device. The effect of VIH on ∆SmO2-m.intercostales were analyzed using a two-way mixed ANOVA test considering the factors (phase × task). Results. ∆SmO2-m.intercostales significantly decreased from 30% (­5.0±4.7%; p<0.01) to 100% (­10.6±12.8%; p<0.01) of the task after eight weeks of VIH. Additionally, an increase in maximal inspiratory pressure (MIP) of 16.5±11.4 cmH2O (p<0.01) and respiratory muscle endurance of 106.6±149.0 s (p<0.01) was reported. Total exercise time increased by 106.6±149.0 s (p=0.04), as well as total workload by 10.50±10.12 watts (p<0.01). Conclusion. VIH reduces COB induced by incremental exercise and is associated with increased physical and respiratory muscle performance. Future studies should explore this respiratory muscle training strategy for individuals with physical limitations related to a premature increase in COB.

Monitoring Changes in Oxygen Muscle during Exercise with High-Flow Nasal Cannula Using Wearable NIRS Biosensors.

Exercise increases the cost of breathing (COB) due to increased lung ventilation (V˙E), inducing respiratory muscles deoxygenation (∇SmO2), while the increase in workload implies ∇SmO2 in locomotor muscles. This phenomenon has been proposed as a leading cause of exercise intolerance, especially in clinical contexts. The use of high-flow nasal cannula (HFNC) during exercise routines in rehabilitation programs has gained significant interest because it is proposed as a therapeutic intervention for reducing symptoms associated with exercise intolerance, such as fatigue and dyspnea, assuming that HFNC could reduce exercise-induced ∇SmO2. SmO2 can be detected using optical wearable devices provided by near-infrared spectroscopy (NIRS) technology, which measures the changes in the amount of oxygen bound to chromophores (e.g., hemoglobin, myoglobin, cytochrome oxidase) at the target tissue level. We tested in a study with a cross-over design whether the muscular desaturation of m.vastus lateralis and m.intercostales during a high-intensity constant-load exercise can be reduced when it was supported with HFNC in non-physically active adults. Eighteen participants (nine women; age: 22 ± 2 years, weight: 65.1 ± 11.2 kg, height: 173.0 ± 5.8 cm, BMI: 21.6 ± 2.8 kg·m-2) were evaluated in a cycle ergometer (15 min, 70% maximum watts achieved in ergospirometry (V˙O2-peak)) breathing spontaneously (control, CTRL) or with HFNC support (HFNC; 50 L·min-1, fiO2: 21%, 30 °C), separated by seven days in randomized order. Two-way ANOVA tests analyzed the ∇SmO2 (m.intercostales and m.vastus lateralis), and changes in V˙E and ∇SmO2·V˙E-1. Dyspnea, leg fatigue, and effort level (RPE) were compared between trials by the Wilcoxon matched-paired signed rank test. We found that the interaction of factors (trial × exercise-time) was significant in ∇SmO2-m.intercostales, V˙E, and (∇SmO2-m.intercostales)/V˙E (p < 0.05, all) but not in ∇SmO2-m.vastus lateralis. ∇SmO2-m.intercostales was more pronounced in CTRL during exercise since 5' (p < 0.05). Hyperventilation was higher in CTRL since 10' (p < 0.05). The ∇SmO2·V˙E-1 decreased during exercise, being lowest in CTRL since 5'. Lower dyspnea was reported in HFNC, with no differences in leg fatigue and RPE. We concluded that wearable optical biosensors documented the beneficial effect of HFNC in COB due to lower respiratory ∇SmO2 induced by exercise. We suggest incorporating NIRS devices in rehabilitation programs to monitor physiological changes that can support the clinical impact of the therapeutic intervention implemented.

Factor de crecimiento análogo a insulina-1 y cardiotrofina-1 inducido por ejercicio y su relación con hipertrofia miocárdica en maratonistas

Antecedentes: El ejercicio de alta intensidad induce hipertrofia miocárdica necesaria para adaptar al corazón a la mayor demanda de trabajo. Se desconoce si correr una maratón induce de forma aguda factores humorales asociados al desarrollo de hipertrofia miocárdica en atletas. Objetivo: Evaluar cardiotrofina-1 (CT1) y el factor de crecimiento análogo a insulina-1 (IGF-1), conocidos inductores de hipertrofia, en maratonistas previo y justo después de correr una maratón y su relación con hipertrofia cardíaca. Métodos: Estudio prospectivo ciego simple de atletas hombres que corrieron la maratón de Santiago. Se incluyó un grupo control sedentario. En todos los sujetos se realizó un ecocardiograma transtorácico estándar. Los niveles de CT1 e IGF-1 se determinaron en plasma obtenidos antes (basal) y justo después de haber terminado (antes de 15 minutos) la maratón, usando test de ELISA. Resultados: Los atletas tenían frecuencias cardíacas menores que los controles, asociado con una mayor hipertrofia miocárdica, determinado por el grosor del septo y pared posterior del corazón, y volúmenes del ventrículo y aurícula izquierda. Los niveles basales de CT1 e IGF-1 fueron similares entre atletas y controles sedentarios. El correr la maratón aumentó los niveles de estas dos hormonas en un subgrupo de atletas. Solo los atletas que incrementaron los niveles de IGF-1, pero no de CT1, tenían volúmenes de ventrículo izquierdo y derecho más grandes que los otros atletas. Conclusiones: IGF-1 que se incrementa de forma aguda por el ejercicio, pero no CT1, estaría asociado con el aumento de los volúmenes ventriculares observado en los atletas.

Background: High intensity exercise induces the development of myocardial hypertrophy necessary to adapt the heart to the increased work demand. Whether running a marathon is associated with acutely induced humoral factors responsible for the development of myocardial hypertrophy observed in athletes is not known. Objective: To evaluate the levels of cardiotrophin-1 (CT1) and insulin-like growth factor-1 (IGF-1), known hypertrophy inducers, in marathon runners before and just after running a marathon and their relationship with cardiac hypertrophy. Methodology: Single-blind prospective study of male athletes who ran the Santiago's marathon. A sedentary control group was included. All subjects underwent a standard transthoracic echocardiogram. CT1 and IGF-1 levels were determined in plasma obtained before (basal) and just after finishing (within 15 min) the marathon using ELISA assays. Results: Athletes had lower heart rates than controls, associated with greater myocardial hypertrophy, as determined by thickness of the heart's septum and posterior wall, and left atrial and ventricular volumes. Basal CT1 and IGF-1 levels were similar between athletes and sedentary controls. Marathon running increased the levels of these two hormones in a subgroup of athletes. Only the athletes who increased IGF-1 levels, but not CT1, had larger left and right ventricular volumes. Conclusion: IGF-1 acutely increased by exercise, but not CT1, was associated with the augmented ventricular volumes observed in athletes.

Systemic and Pulmonary Inflammation/Oxidative Damage: Implications of General and Respiratory Muscle Training in Chronic Spinal-Cord-Injured Patients.

Chronic spinal cord injury affects several respiratory-function-related parameters, such as a decrease in respiratory volumes associated with weakness and a tendency to fibrosis of the perithoracic muscles, a predominance of vagal over sympathetic action inducing airway obstructions, and a difficulty in mobilizing secretions. Altogether, these changes result in both restrictive and obstructive patterns. Moreover, low pulmonary ventilation and reduced cardiovascular system functionality (low venous return and right stroke volume) will hinder adequate alveolar recruitment and low O2 diffusion, leading to a drop in peak physical performance. In addition to the functional effects described above, systemic and localized effects on this organ chronically increase oxidative damage and tissue inflammation. This narrative review describes both the deleterious effects of chronic spinal cord injury on the functional effects of the respiratory system as well as the role of oxidative damage/inflammation in this clinical context. In addition, the evidence for the effect of general and respiratory muscular training on the skeletal muscle as a possible preventive and treatment strategy for both functional effects and underlying tissue mechanisms is summarized.

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

Respiratory muscle training (RMT) improves physical performance, although it is still debated whether this effect depends on the type of training. The purpose of this study was to compare the effects of two different types of RMT, i.e., voluntary isocapnic hyperpnea (VIH) and inspiratory threshold loading (ITL), on the deoxygenation of intercostal (ΔSmO2-m. intercostales) and vastus lateralis (ΔSmO2-m. vastus lateralis) muscles during exercise. Twenty-four participants performed eight weeks of RMT by: (i) VIH (3 days·week-1 for 12 min at 60% maximal voluntary ventilation) or (ii) ITL (5 sets·week-1 of 30 breaths·minute-1 at 60% maximal inspiratory pressure). Cardiopulmonary exercise testing (CPET) included ΔSmO2 (the change from baseline to end of test) of intercostal and vastus lateralis muscles. After RMT, both groups showed decreased ΔSmO2-m. intercostales (VIH = 12.8 ± 14.6%, p = 0.04 (effect size, ES = 0.59), and ITL = 8.4 ± 9.8%, p = 0.04 (ES = 0.48)), without a coincident change of ∆SmO2-m. vastus lateralis. ITL training induced higher V˙O2-peak absolute values than VIH (mean Δ post-pre, ITL = 229 ± 254 mL·min-1 [95% CI 67-391] vs. VIH, 39 ± 153 mL·min-1 [95% CI -58-136.0], p = 0.01). In conclusion, both RMT improved the balance between supply and oxygen consumption levels of m. intercostales during CPET, with ITL also inducing an increase of aerobic capacity.

Terapia de alto flujo ¿Una alternativa en rehabilitación? / High flow therapy: An option to rehabilitation?

La pandemia por el virus SARS-COV2 que causó la enfermedad COVID-19 ha traído grandes desafíos al sistema de salud tanto a nivel nacional como mundial. En Chile, gracias al esfuerzo de organismos gubernamentales e instituciones privadas, los centros de salud se han equipado con distintos dispositivos de terapia ventilatoria (ventilación mecánica invasiva y no invasiva, y terapia de alto flujo de oxígeno mediante cánula nasal (TAF) con la finalidad de abarcar mayor atención de pacientes tras un periodo de crisis sanitaria que colapsó las redes de atención secundaria y terciaria de salud. En concordancia a esto, es interesante evaluar qué utilidad puede darse a estos equipos posterior a la pandemia, considerando que en varios centros de salud se duplicó o triplicó la disponibilidad de recursos técnicos. En este contexto, la TAF entrega efectos fisiológicos favorables y útiles en escenarios clínicos que implican aumento de las demandas ventilatorias, no sólo en condiciones de insuficiencia respiratoria hipoxémica aguda, sino en condiciones en donde el ejercicio aeróbico es un pilar fundamental, como es el caso de los diferentes programas de rehabilitación (cardiovascular, respiratorio, metabólico, etc.) incluidos como Garantías Explícitas de Salud (GES). Así, la incorporación de TAF en la rehabilitación pulmonar sería una opción adecuada en pacientes con disfunciones respiratorias crónicas, ampliando la cobertura sanitaria que estos programas tienen hoy en día.

The SARS-COV2 pandemic that caused the COVID-19 disease has brought significant challenges to the health system nationally and globally. In Chile, thanks to the efforts of government agencies and private institutions, health centres have been equipped with di-fferent ventilatory therapy devices (invasive and non-invasive mechanical ventilation, and high-flow oxygen therapy by nasal cannula (HFOT)), in order to cover more patient care after a period of a health crisis that collapsed secondary and tertiary health care networks. Accordingly, it is interesting to evaluate concerning what use can be given to these teams after the pandemic, even more considering that the availability of technical resources doubled or tripled in several health centres. In this context, HFOT provides favourable and useful physiological effects in clinical scenarios that involve increased ventilatory demands, not only in conditions of acute hypoxemic respiratory failure but also in conditions where aerobic exercise is a fundamental pillar, as is the case of the different rehabilitation programs (cardiovascular, respiratory, metabolic, etc.) included as Health Guarantees (Garantías Explicitas en Salud, GES). Thus, incorporating HFOT in pulmonary rehabilitation would be an appropriate option in patients with chronic respiratory dysfunctions, expanding the health coverage that these programs have today.

Pronóstico kinesiológico cardiorrespiratorio: un enfoque biopsicosocial / Cardiorespiratory Kinesiological Prognosis: a biopsychosocial approach

La kinesiología, fisioterapia o terapia física, se ha desarrollado de manera permanente a través de una perspectiva biopsicosocial, en la que identificar el contexto biomédico del usuario, junto con sus limitaciones en la actividad y restricciones en la participación es esencial para una atención individualizada del usuario en su contexto. Entidades como la Asociación Americana de Terapia Física (American Physical Therapist Association, APTA) y la Conferencia Mundial de Terapia Física (World Confederation for Physical Therapy, WCPT) o actualmente conocida como Fisioterapia Mundial (World Physiotherapy, WP), conceden como aspecto propio del kinesiólogo o fisioterapeuta la acción de diagnosticar, evaluar, tratar y pronosticar las disfunciones de usuarios con necesidades de atención en salud. Sin embargo, algunas de estas competencias profesionales no están del todo definidas para su aplicación en la práctica clínica. El presente artículo de comunicación profesional entrega las bases conceptuales en la que se sostienen los hitos necesarios para esta-blecer una propuesta metodológica de elaboración del pronóstico kinesiológico funcional basado en el área cardiorrespiratoria con un enfoque biopsicosocial según la Clasificación Internacional del Funcionamiento, de la Discapacidad y de la Salud (CIF). Esto, con la finalidad de que el pronóstico funcional sea incorporado como parte de la formación curricular en la profesión, así como dentro de un proceso continuo en la práctica kinesiológica

Kinesiology, Physiotherapy or Physical Therapy has been permanently developed on a biopsychosocial perspective. Identifying the user's biomedical context, along with his or her activity limitations and participation restrictions, is essential for individualized attention to the user in his or her context. Entities such as the American Physical Therapy Association and the World Confederation for Physical Therapy, or currently known as World Physiotherapy, give the kinesiologist or physical therapist the task of diagnosing, evaluating, treating, and predicting the dysfunctions of users with health care needs. However, some of these professional compe-tencies are not wholly defined for application in clinical practice, and less, in the curricular formation of the physiotherapy students. This article gives helpful concepts to elaborate a biopsychosocial cardiorespiratory functional prognosis for Kinesiology, based on the International Classification of Functioning, Disability, and Health (ICF), to incorporate as part of the curricular formation in the profession and within a continuous process in kinesiological practice

Eccentric Training in Pulmonary Rehabilitation of Post-COVID-19 Patients: An Alternative for Improving the Functional Capacity, Inflammation, and Oxidative Stress.

The purpose of this narrative review is to highlight the oxidative stress induced in COVID-19 patients (SARS-CoV-2 infection), describe longstanding functional impairments, and provide the pathophysiologic rationale that supports aerobic eccentric (ECC) exercise as a novel alternative to conventional concentric (CONC) exercise for post-COVID-19 patients. Patients who recovered from moderate-to-severe COVID-19 respiratory distress demonstrate long-term functional impairment. During the acute phase, SARS-CoV-2 induces the generation of reactive oxygen species that can be amplified to a "cytokine storm". The resultant inflammatory and oxidative stress process causes organ damage, particularly in the respiratory system, with the lungs as the tissues most susceptible to injury. The acute illness often requires a long-term hospital stay and consequent sarcopenia. Upon discharge, muscle weakness compounded by limited lung and cardiac function is often accompanied by dyspnea, myalgia, anxiety, depression, and sleep disturbance. Consequently, these patients could benefit from pulmonary rehabilitation (PR), with exercise as a critical intervention (including sessions of strength and endurance or aerobic exercises). Unfortunately, conventional CONC exercises induce significant cardiopulmonary stress and increase inflammatory and oxidative stress (OS) when performed at moderate/high intensity, which can exacerbate debilitating dyspnoea and muscle fatigue post-COVID-19. Eccentric training (ECC) is a well-tolerated alternative that improves muscle mass while mitigating cardiopulmonary stress in patients with COPD and other chronic diseases. Similar benefits could be realized in post-COVID-19 patients. Consequently, these patients could benefit from PR with exercise as a critical intervention.

Cánula Nasal de Alto Flujo en Adultos con Enfermedades Respiratorias Crónicas durante el Ejercicio Físico: Protocolo de Revisión Sistemática y Metaanálisis / High-Flow Nasal Cannula in Adults with Chronic Respiratory Diseases during Physical Exercise: A Protocol Systematic Review and Meta-analysis

Introducción. El entrenamiento físico puede mejorar la capacidad de ejercicio, la disnea y la calidad de vida (CV) en pacientes con enfermedades respiratorias crónicas (ERC). En este contexto, el uso de oxígeno suplementario a través de una cánula nasal de alto flujo (CNAF) podría ser un dispositivo que permita tolerar mayores niveles de actividad con menos síntomas de esfuerzo físico, optimizando en última instancia la capacidad de ejercicio y la CV. Objetivo. Este protocolo pretende conducir una revisión sistemática para evaluar el efecto terapéutico de la CNAF durante el ejercicio físico en pacientes con ERC. Fuente de búsqueda. Se realizarán búsquedas en el Registro Cochrane Central de Ensayos Controlados (CENTRAL), PUBMED, Embase, Lilacs, Physiotherapy Evidence Database (PEDro), International Clinical Trials Registry Platform (ICTRP), ClinicalTrials.gov y literatura gris. Criterios de elegibilidad. Examinaremos los ECA de acuerdo con los criterios de elegibilidad para su inclusión en nuestra revisión. Dos revisores examinarán de forma independiente cada estudio para la elegibilidad, la extracción de datos y la evaluación del riesgo de sesgo. Se combinarán los resultados mediante un metanálisis y se aplicará el sistema GRADE para evaluar la certeza de las pruebas para cada resultado. La medida de resultado primaria será la capacidad de ejercicio, y las medidas de resultado secundarias serán la calidad de vida, la disnea, la funcionalidad, la comodidad, las complicaciones y adherencia. Se realizarán metaanálisis para determinar la diferencia de medias (DM) o la DM estandarizada para los datos continuos y la razón de riesgo para los datos dicotómicos. Se realizarán análisis de subgrupos según los tipos y la gravedad de la enfermedad, las condiciones de ejercicio físico y el estado de los dispositivos de oxigenoterapia. Ética y difusión. Como los investigadores no accederán a información que pueda conducir a la identificación de un participante individual, no fue necesario a obtener aprobación ética. Número de registro de PROSPERO: CRD42022336263.

Background. Physical training can improve exercise capacity, dyspnoea, and quality of life (QoL) in patients with chronic respiratory diseases (CRDs). It has been suggested that using supplemental oxygen through a high-flow nasal cannula (HFNC) could lead to higher levels of activity to be tolerated with fewer symptoms of physical exertion, ultimately optimizing exercise capacity and QoL. Objective. To conduct a systematic review to assess the therapeutic effect of HFNC during physical exercise in patients with CRDs. We will search the Cochrane Central Register of Controlled Trials (CENTRAL), PUBMED, Embase, Lilacs, Physiotherapy Evidence Database (PEDro), International Clinical Trials Registry Platform (ICTRP), ClinicalTrials.gov, and grey literature. Eligibility criteria. We will examine RCTs according to the eligibility criteria for inclusion in our review. Two reviewers will independently examine each study for eligibility, data extraction, and risk of bias assessment. We will combine the results using meta-analysis and apply the GRADE system to assess the certainty of the evidence for each outcome. The primary outcome will be exercise capacity, and secondary outcomes will be QoL, dyspnoea, functionality, comfort, complications, and adherence. We will perform meta-analyses to determine the mean difference (MD) or standardized MD for continuous data and the risk ratio for dichotomous data. Subgroup analyses will be performed according to types and severity of disease, physical exercise conditions, and condition of oxygen therapy devices. Ethics and Dissemination. As researchers will not access information that could lead to the identification of an individual participant, obtaining ethical approval was waived. Prospero registration number: CRD42022336263.

Determination of the Respiratory Compensation Point by Detecting Changes in Intercostal Muscles Oxygenation by Using Near-Infrared Spectroscopy.

This study aimed to evaluate if the changes in oxygen saturation levels at intercostal muscles (SmO2-m.intercostales) assessed by near-infrared spectroscopy (NIRS) using a wearable device could determine the respiratory compensation point (RCP) during exercise. Fifteen healthy competitive triathletes (eight males; 29 ± 6 years; height 167.6 ± 25.6 cm; weight 69.2 ± 9.4 kg; V˙O2-máx 58.4 ± 8.1 mL·kg−1·min−1) were evaluated in a cycle ergometer during the maximal oxygen-uptake test (V˙O2-máx), while lung ventilation (V˙E), power output (watts, W) and SmO2-m.intercostales were measured. RCP was determined by visual method (RCPvisual: changes at ventilatory equivalents (V˙E·V˙CO2−1, V˙E·V˙O2−1) and end-tidal respiratory pressure (PetO2, PetCO2) and NIRS method (RCPNIRS: breakpoint of fall in SmO2-m.intercostales). During exercise, SmO2-m.intercostales decreased continuously showing a higher decrease when V˙E increased abruptly. A good agreement between methods used to determine RCP was found (visual vs NIRS) at %V˙O2-máx, V˙O2, V˙E, and W (Bland-Altman test). Correlations were found to each parameters analyzed (r = 0.854; r = 0.865; r = 0.981; and r = 0,968; respectively. p < 0.001 in all variables, Pearson test), with no differences (p < 0.001 in all variables, Student's t-test) between methods used (RCPvisual and RCPNIRS). We concluded that changes at SmO2-m.intercostales measured by NIRS could adequately determine RCP in triathletes.

Circulating Vascular Cell Adhesion Molecule-1 (sVCAM-1) Is Associated With Left Atrial Remodeling in Long-Distance Runners.

Introduction: An increased risk of atrial fibrillation (AF) has been demonstrated in high-performance athletes. Soluble vascular adhesion molecule-1 (sVCAM-1), a biomarker involved in inflammation and cardiac remodeling, is associated with the development of AF in the general population. However, the relationship between sVCAM-1 and left atrial (LA) remodeling has been poorly investigated in long-distance runners (LDR). Aim: To determine the association between LA remodeling and sVCAM-1 levels in LDR during the training period before a marathon race. Methods: Thirty-six healthy male LDR (37.0 ± 5.3 years; 174.0 ± 7.0 height; BMI: 23.8 ± 2.8; V°O2-peak: 56.5 ± 7.3 mL·kg-1·min-1) were evaluated in this single-blind and cross-sectional study. The LDR were separated into two groups according to previous training levels: high-training (HT) (n = 18) ≥100 km·week-1 and low-training (LT) (n = 18) ≥70 and <100 km·week-1. Also, 18 healthy non-active subjects were included as a control group (CTR). In all participants, transthoracic echocardiography was performed. sVCAM-1 blood levels were measured baseline and immediately finished the marathon race in LDR. Results: HT showed increased basal levels of sVCAM-1 (651 ± 350 vs. 440 ± 98 ng·mL-1 CTR, p = 0.002; and vs. 533 ± 133 ng·mL-1 LT; p = 0.003) and a post-marathon increase (ΔsVCAM-1) (651 ± 350 to 905 ± 373 ng·mL-1; p = 0.002), that did not occur in LT (533 ± 133 to 651 ± 138 ng·mL-1; p = 0.117). In LDR was a moderate correlation between LA volume and sVCAM-1 level (rho = 0.510; p = 0.001). Conclusions: In male long-distance runners, sVCAM-1 levels are directly associated with LA remodeling. Also, the training level is associated with basal sVCAM-1 levels and changes after an intense and prolonged exercise (42.2 km). Whether sVCAM-1 levels predict the risk of AF in runners remains to be established.

Sex-Differences in the Oxygenation Levels of Intercostal and Vastus Lateralis Muscles During Incremental Exercise.

This study aimed to examine sex differences in oxygen saturation in respiratory (SmO2-m.intercostales) and locomotor muscles (SmO2-m.vastus lateralis) while performing physical exercise. Twenty-five (12 women) healthy and physically active participants were evaluated during an incremental test with a cycle ergometer, while ventilatory variables [lung ventilation ( V . E), tidal volume (Vt), and respiratory rate (RR)] were acquired through the breath-by-breath method. SmO2 was acquired using the MOXY® devices on the m.intercostales and m.vastus lateralis. A two-way ANOVA (sex × time) indicated that women showed a greater significant decrease of SmO2-m.intercostales, and men showed a greater significant decrease of SmO2-m.vastus lateralis. Additionally, women reached a higher level of ΔSmO2-m.intercostales normalized to V . E (L⋅min-1) (p < 0.001), whereas men had a higher level of ΔSmO2-m.vastus lateralis normalized to peak workload-to-weight (watts⋅kg-1, PtW) (p = 0.049), as confirmed by Student's t-test. During an incremental physical exercise, women experienced a greater cost of breathing, reflected by greater deoxygenation of the respiratory muscles, whereas men had a higher peripheral load, indicated by greater deoxygenation of the locomotor muscles.

Left Cardiac Remodelling Assessed by Echocardiography Is Associated with Rho-Kinase Activation in Long-Distance Runners.

This single-blind and cross-sectional study evaluated the role of Rho-kinase (ROCK) as a biomarker of the cardiovascular remodelling process assessed by echocardiography in competitive long-distance runners (LDRs) during the training period before a marathon race. Thirty-six healthy male LDRs (37.0 ± 5.3 years; 174.0 ± 7.0 height; BMI: 23.8 ± 2.8; V˙ O2-peak: 56.5 ± 7.3 mL·kg-1·min-1) were separated into two groups according to previous training level: high-training (HT, n = 16) ≥ 100 km·week-1 and low-training (LT, n = 20) ≥ 70 and < 100 km·week-1. Also, twenty-one healthy nonactive subjects were included as a control group (CTR). A transthoracic echocardiography was performed and ROCK activity levels in circulating leukocytes were measured at rest (48 h without exercising) the week before the race. The HT group showed a higher left ventricular mass index (LVMi) and left atrial volume index (LAVi) than other groups (p < 0.05, for both); also, higher levels of ROCK activity were found in LDRs (HT = 6.17 ± 1.41 vs. CTR = 1.64 ± 0.66 (p < 0.01); vs. LT = 2.74 ± 0.84; (p < 0.05)). In LDRs a direct correlation between ROCK activity levels and LVMi (r = 0.83; p < 0.001), and LAVi (r = 0.70; p < 0.001) were found. In conclusion, in male competitive long-distance runners, the load of exercise implicated in marathon training is associated with ROCK activity levels and the left cardiac remodelling process assessed by echocardiography.

Soluble Interleukin-6 Receptor Regulates Interleukin-6-Dependent Vascular Remodeling in Long-Distance Runners.

Little is known about the effects of training load on exercise-induced plasma increase of interleukin-6 (IL-6) and soluble IL-6 receptor (sIL-6R) and their relationship with vascular remodeling. We sought to evaluate the role of sIL 6R as a regulator of IL-6-induced vascular remodeling. Forty-four male marathon runners were recruited and allocated into two groups: low-training (LT, <100 km/week) and high-training (HT, ≥100 km/week), 22 athletes per group. Twenty-one sedentary participants were used as reference. IL-6, sIL-6R and sgp130 levels were measured in plasma samples obtained before and immediately after finishing a marathon (42.2-km). Aortic diameter was measured by echocardiography. The inhibitory effect of sIL-6R on IL-6-induced VSMC migration was assessed using cultured A7r5 VSMCs. Basal plasma IL-6 and sIL-6R levels were similar among sedentary and athlete groups. Plasma IL-6 and sIL-6R levels were elevated after the marathon, and HT athletes had higher post-race plasma sIL-6R, but not IL-6, level than LT athletes. No changes in sgp130 plasma levels were found in LT and HT groups before and after running the marathon. Athletes had a more dilated ascending aorta and aortic root than sedentary participants with no differences between HT and LT athletes. However, a positive correlation between ascending aorta diameter and plasma IL-6 levels corrected by training load and years of training was observed. IL-6 could be responsible for aorta dilation because IL-6 stimulated VSMC migration in vitro, an effect that is inhibited by sIL-6R. However, IL-6 did not modify cell proliferation, collagen type I and contractile protein of VSMC. Our results suggest that exercise induces vascular remodeling. A possible association with IL-6 is proposed. Because sIL-6R inhibits IL-6-induced VSMC migration, a possible mechanism to regulate IL-6-dependent VSMC migration is also proposed.

Intercostal Muscles Oxygenation and Breathing Pattern during Exercise in Competitive Marathon Runners.

The study aimed to evaluate the association between the changes in ventilatory variables (tidal volume (Vt), respiratory rate (RR) and lung ventilation (V.E)) and deoxygenation of m.intescostales (∆SmO2-m.intercostales) during a maximal incremental exercise in 19 male high-level competitive marathon runners. The ventilatory variables and oxygen consumption (V.O2) were recorded breath-by-breath by exhaled gas analysis. A near-infrared spectroscopy device (MOXY®) located in the right-hemithorax allowed the recording of SmO2-m.intercostales. To explore changes in oxygen levels in muscles with high demand during exercise, a second MOXY® records SmO2-m.vastus laterallis. The triphasic model of exercise intensity was used for evaluating changes in SmO2 in both muscle groups. We found that ∆SmO2-m.intercostales correlated with V.O2-peak (r = 0.65; p = 0.002) and the increase of V.E (r = 0.78; p = 0.001), RR (r = 0.54; p = 0.001), but not Vt (p = 0.210). The interaction of factors (muscles × exercise-phases) in SmO2 expressed as an arbitrary unit (a.u) was significant (p = 0.005). At VT1 there was no difference (p = 0.177), but SmO2-m.intercostales was higher at VT2 (p < 0.001) and V.O2-peak (p < 0.001). In high-level competitive marathon runners, the m.intercostales deoxygenation during incremental exercise is directly associated with the aerobic capacity and increased lung ventilation and respiratory rate, but not tidal volume. Moreover, it shows less deoxygenation than m.vastus laterallis at intensities above the aerobic ventilatory threshold.

Oxigenación de músculos respiratorios y locomotores durante el test cardiopulmonar en pacientes con circulación de fontan: serie de casos / Patients with fontan: oxygen consumption in respiratory and Locomotor muscles during excersie testing

Resumen: Antecedentes: Los pacientes con circulación de Fontan (PCF) presentan limitación cardíaca durante el esfuerzo máximo lo que repercute en menor capacidad de ejercicio (VO2-peak). La rehabilitación cardiovascular (RC) revierte este desacondicionamiento, al aumentar el gasto cardíaco y diferencia arteriovenosa de oxígeno, aspectos evaluados con monitorización invasiva y gases exhalados. La valoración no invasiva de la saturación muscular de oxígeno (SmO2) es un método de reciente aplicación para evaluar la limitación muscular al ejercicio. En PCF esta limitación puede atribuirse a la mayor acción de músculos respiratorios (cambios ventilatorios) y/o locomotores (carga periférica). Objetivo: Evaluar el trabajo de músculos respiratorios y locomotores durante el ejercicio físico máximo e incremental mediante los cambios en la SmO2. Métodos: A seis PCF (5 hombres; 13.8±2.9 años; 158±9cm; 49.8±13.3 kg) se les valoró el VO2-peak (23.0±4.5mL·kg-1·min-1) mediante ciclo-ergoespirometría sincrónicamente con SmO2 en músculos respiratorios (SmO2-m.Intercostales) y locomotores (SmO2-m.Vastus-Laterallis) mediante espectroscopía cercana al rango infrarrojo durante el test cardiopulmonar. Resultados: SmO2-m.Intercostales disminuyó desde el 60% del VO2-peak (p<0.05), mientras que SmO2-m.Vastus-Laterallis no cambió. La ventilación pulmonar (VE) aumentó progresivamente, siendo significativo a partir del 60% VO2-peak (p<0.05). La mayor desoxigenación de SmO2-m.Intercostales (∆SmO2) se asoció con los máximos cambios en ventilación pulmonar (∆VE) en ejercicio (rho=0.80; p=0.05). Conclusiones: Durante un protocolo de esfuerzo, los pacientes con circulación de Fontan presentan mayor trabajo muscular respiratorio que locomotor. Los cambios en la ventilación pulmonar se asocian a mayor extracción de oxígeno en la musculatura respiratoria, reforzando la necesidad de incorporar el entrenamiento respiratorio en la rehabilitación cardiovascular.

Abstract: Background: During a maximum incremental exercise patients with Fontan circulation (PFC) show cardiac limitation reducing aerobic exercise capacity (VO2-peak). Cardiovascular rehabilitation (CR) reverses this deconditioning by increasing cardiac output and arteriovenous oxygen difference, aspects that can be evaluated by invasive methods and analyzing the exhaled gases. Non-invasive assessment of muscle oxygen saturation (SmO2) is a novel method for recording local oxygen levels. By this technology, it is possible to evaluate the muscle limitation to exercise. In PFC, that limitation could be attributed to higher contractions of respiratory (ventilatory changes) and/ or locomotor muscles (peripheral load). Objective: To evaluate in PFC the changes at SmO2 of respiratory and locomotor muscles during a maximum and incremental exercise protocol (cardiopulmonary test, VO2-peak). Methods: Six PFC (5 men; 13.8±2.9 years; 158±9 cm; 49.8±13.3 kg) were assessed during the VO2peak test (23.0±4.5mL·kg-1·min-1) by cyclo-ergospirometry synchronously with SmO2 at respiratory (SmO2-m.Intercostales) and locomotor (SmO2-m. Vastus-Laterallis) muscles by Near-Infrared Spectroscopy (NIRS). Results: SmO2-m.Intercostales decreased from 60% of VO2-peak (p<0.05), while SmO2-m.Vastus-Laterallis did not change. Minute ventilation (VE) increased progressively, showing changes to rest at 60% of VO2-peak (p<0.05). The higher deoxygenation of SmO2-m.Intercostales (∆SmO2) correlated to maximum changes of lung ventilation (∆VE) (rho=0.80; p=0.05). Conclusions: During an incremental and maximum exercise protocol, patients with Fontan circulation have more work at respiratory than locomotor muscles. Changes in VE are direct associated with greater extraction of oxygen at respiratory muscles, reinforcing the incorporation of respiratory muscle training in cardiovascular rehabilitation.

Asociación entre el Material Particulado y la Función Pulmonar durante el Ejercicio en Sujetos Físicamente Activos / Association between particulate matter and lung function during exercise in physically active subjects

Introducción: El material particulado (MP) es una mezcla de partículas potencialmente peligrosas debido a su capacidad de penetrar el sistema respiratorio. La cantidad de MP que ingresa al organismo depende de su concentración ambiental, tiempo de exposición y la ventilación pulmonar. Esta última aumenta fisiológicamente durante el ejercicio físico. Objetivo: Determinar la asociación entre el MP y la función pulmonar. Métodos: Los participantes completaron un protocolo de actividad física en condiciones ambientales con concentraciones de MP habituales durante 4 días consecutivos (24-km). La función pulmonar fue evaluada antes (día-0) y después de una exposición aguda (día-1, post 6-km) y exposición prolongada (día-4, post 24-km). Para determinar la correlación entre los niveles de MP y las variables de función pulmonar, se aplicó la prueba de correlación de Spearman. El nivel de significancia se estableció en p<0.05. Resultados: La función pulmonar, evaluada a través de las variables de espirometría de volumen espiratorio forzado al primer segundo (VEF1), su relación con la capacidad vital forzada (VEF1/CVF) y flujo espiratorio medio (FEF25-75%), se asoció inversamente con las concentraciones de MP en el día-1 (p<0.05), pero no en el día-4 (p>0.05). Conclusión: Este estudio encontró que a mayor dosis efectiva de MP inhalado, mayor es la disminución en variables de función pulmonar evaluadas con espirometría. Este efecto fue más notorio posterior a la exposición aguda que a la exposición prolongada, infiriendo una posible habituación por parte del sistema respiratorio a la inhalación permanente de material particulado.

Introduction: Particulate matter (PM) is a mixture of potentially dangerous particles due to its ability to penetrate the respiratory system. The amount of PM that enters the body depends on its environmental concentration, the exposure time and pulmonary ventilation. The latter increase physiologically during physical exercise. Objective: To determine the association between MP and lung function in physically active young adults during physical exercise. Methods: the subjects completed a physical activity protocol in environmental conditions with habitual PM concentrations for four consecutive days (24-km). Lung function was evaluated before (day-0) and after acute exposure (day-1, post-6-km) and prolonged exposure (day-4, post-24-km). To determine the correlation between MP levels and lung function variables, the Spearman correlation test was applied. The level of significance was established at p <0.05. Results: Lung function, evaluated through the spirometry variables of forced expiratory volume in the first second (FEV1), its relationship with forced vital capacity (FEV1 / FVC) and mean expiratory flow (FEF25-75%) was inversely associated with MP concentrations on day-1 (p<0.05), but not on day-4 (p>0.05). Conclusion: This study found that the higher the effective dose of inhaled PM, the greater the decrease in lung function variables evaluated with spirometry. This effect is more noticeable after acute exposure than after prolonged exposure, inferring the respiratory system's possible habituation to permanent inhalation of particulate matter.

Humidity prevents the exercise-induced formation of hydrogen peroxide and nitrite in exhaled breath condensate in recreational cyclists.

PURPOSE: The aerobic exercise affects the respiratory redox-state. The influence of different relative humidity (RH) levels on the formation of respiratory reactive chemical species associated with redox-state altered by exercise has been poorly explored. Our aim was to evaluate the effect of two different RH conditions (40% vs. 90%) on the concentration of hydrogen peroxide and nitrite in exhaled breath condensate ([H2O2]EBC and [NO2-]EBC) and spirometry parameters in recreational cyclists. METHODS: Sixteen men and women (12/4) (mean age ± SD: 23.5 ± 2.2 years) completed 60-min of cycling at 166.3 ± 26.9 watts (70% of maximum load of [Formula: see text]-max. test, 49.3 ± 7.6 mL·min-1·kg-1) at random 40%-RH and 90%-RH conditions separated by 7 days. The two-way RM-ANOVA test was applied to compare [H2O2]EBC, [NO2-]EBC, [NO2-]EBC/[NO2-]Plasma at rest and 80-min post-exercise (80-post); and spirometry parameters at rest, 20-post and 80-post. RESULTS: The interaction of factors (humidity × time) was significant in [H2O2]EBC, [NO2-]EBC, [NO2-]EBC/[NO2-]Plasma (p = 0.005, p = 0.030, p = 0.043, respectively). At 40%-RH conditions, the same parameters were higher in 80-post than at rest (p < 0.001, p = 0.001, p = 0.014, respectively). At the same time, the [H2O2]EBC and [NO2-]EBC/[NO2-]Plasma were higher in 40%-RH than 90%-RH (p = 0.010, p < 0.001, respectively). The interaction was significant in FEV1 (p = 0.013) and FEF25-75% (p = 0.023), but not in FEV1/FVC (p = 0.362). At 80-post, the changes are kept in 90%-RH (p < 0.001), diminishing in 40%-RH being similar to rest. CONCLUSION: In recreational cyclists, 90%-RH prevents the increase of hydrogen peroxide and nitrite in exhaled breath condensate samples observed at 40%-RH and prolonging the bronchodilation until 80-post cycling exercise.

Nonalcoholic fatty liver disease and sarcopenia: pathophysiological connections and therapeutic implications.

INTRODUCTION: Nonalcoholic fatty liver disease (NAFLD) is currently one of the most common liver diseases worldwide. Recent data suggest that loss of skeletal muscle mass and function (i.e. sarcopenia) is highly prevalent and frequently overlooked in NAFLD patients. Experimental and clinical data suggest that the relationship between NAFLD and sarcopenia is pathophysiologically complex and bi-directional and there is a growing interest in unveiling how sarcopenia could influence NAFLD development and progression. AREAS COVERED: PubMed/MEDLINE was searched for articles related to concomitant occurrence of NAFLD and sarcopenia between January 2013 and April 2020. Areas covered in this review include: (1) updated sarcopenia diagnosis strategy, (2) discussion of current data on pathophysiological connections between NAFLD and sarcopenia, and (3) analysis of current and future therapeutic implications of this knowledge. EXPERT OPINION: Clinical studies describe a consistent association between NAFLD and sarcopenia, although a cause-effect relation remains to be determined. Active implementation of current diagnosis algorithms and optimized treatment can prevent sarcopenia related complications in subjects with NAFLD. Pathogenic pathways implicated in this relation are multiple and complex, a better understanding of them can provide novel biomarkers and targeted therapies that will hopefully have an important impact in NAFLD management.

Razonamiento clínico en kinesiología mediante aprendizaje basado en casos / Clinical reasoning in kinesiology by case-based learning

Introducción: En cursos clínicos con gran número de estudiantes, las experiencias clínicas con pacientes reales son limitadas, dificul-tando el logro de objetivos de aprendizaje. La didáctica aprendizaje basado en casos (ABC) promueve el pensamiento crítico y trabajo coolaborativo, aspectos esenciales para desarrollar competencias profesionales. El objetivo de este estudio fue reportar si la incorpo-ración de la metodología ABC en una asignatura clínica curricular promueve el razonamiento clínico en la formación en kinesiología. Metodología: En la asignatura curricular "evaluación cardiorrespiratoria en kinesiología", 10 grupos de 7 estudiantes desarrollaron casos clínicos de temas disciplinares seleccionados bajo criterio de jueces por expertos del área, y lo presentaron al resto de sus compañeros. Un académico guió la reflexión del tema tratado en el ABC, fomentando la discusión entre los estudiantes. Al finalizar la asignatura se evaluó la percepción de la didáctica educativa mediante encuesta y logro de objetivos de aprendizaje con indicadores académicos. Resultados: Los estudiantes reportaron gran satisfacción con la metodología, mayor preparación para actividades de campo clínico y mejoras en sus habilidades comunicacionales. El promedio obtenido en las interrogaciones y en las actividades clínicas fue superior a versiones previas de la asignatura, aumentando el porcentaje de aprobación y satisfacción con el curso. Conclusión: La incorporación de la didáctica de ABC fomentó el razonamiento clínico, reflexión y habilidades comunicacionales mejorando el rendimiento académico y promoviendo competencias profesionales. Como producto final se elaboró un libro de descarga libre con los temas tratados en los ABC, titulado: "Identificando problemas kinesiológicos: aprendizaje basado en casos".

Introduction: In clinical courses with a large number of students, clinical experiences with real patients are limited, difficult to achieve the learning objectives. The 'Case-Based Learning' (CBL), like educational methodology, promotes critical thinking and improve collaborative work, which are essential aspects of the development of professional skills. The objective of this study was to report how the incorporation of the CBL methodology in a clinical course promoted the clinical reasoning in kinesiology students. Methodology: In the curriculum subject ten groups of seven students analyzed different clinical cases and presented them to their classmates. The CBL topics were selected by academic experts, who also guided and encouraged the discussion among the students. An online survey at the end of the course assessed perceptions students participated in this methodology. The final academic indicators assessed the learning objectives of the course achieved by students that participated with this methodology. Results: The students reported high satisfaction with the CBL methodology. They showed better preparation for clinical experiences and an improvement in their communication skills. The final marks obtained in the interrogations and the clinical practice activities were higher than in previous years. There was an increase in academic approval and student satisfaction with the course. Conclusion: The incorporation of the CBL methodology enhanced clinical reasoning, reflection, and communication skills, improving academic performance, and promoting professional skills. The topics covered in the CBLs conformed a free download book, entitled: «Identifying kinesiology problems: case-based learning.