Ventilatory Pattern Influences Tolerance to Normobaric Hypoxia in Healthy Adults.

INTRODUCTION: Tolerance to breathing in conditions with a decreased oxygen ratio is subject-specific. A normobaric hypoxia tolerance test (NHTT) is performed to assess the ability of each individual, as this may be influenced by genetic or personal factors such as age or gender. The aim of this study is to test the influence of deep breathing on hypoxia tolerance time. MATERIAL AND METHODS: A total of 45 subjects (21 parachutists and 24 students) performed two NHTTs at 5050 m altitude (iAltitude). Arterial (SatO2) and muscle (SmO2) oxygen saturation were monitored with the Humon Hex® device. The first NHTT was performed with free breathing, without any instructions; and the second NHTT was performed with wide, slow, diaphragmatic breathing. The NHTT was terminated at the end of 10 min or when a value of less than 83% was obtained. RESULTS: The first NHTT was completed by 38.1% of parachutist and 33.3% of students while the second NHTT was completed by 85.7% and 75%, respectively. In the second NHTT, both parachutists and students had a significantly (p = 0.001) longer duration compared to the first NHTT. SmO2 and SatO2 values also increased significantly (p < 0.001) in both groups (p < 0.05). CONCLUSION: Performing controlled diaphragmatic breathing is successful in increasing hypoxia tolerance time and/or SatO2 values.

Estudio de la variabilidad de la frecuencia cardiaca tras la exposición a la hipoxia normobárica / Study of heart rate variability after exposure to normobaric hypoxia

La variabilidad de la frecuencia cardiaca (VFC) es una herramienta capaz de analizar y valorar la actividad vegetativa sobre el corazón ante diversas actividades y situaciones. Consiste en medir el tiempo que trascurre entre cada dos latidos cardiacos durante un periodo de tiempo y expresarlo en función de ecuaciones matemáticas y estadísticas. Otros autores han analizado la influencia de diferentes estresores sobre la VFC. En este trabajo buscamos la acción de la hipoxia normobárica (HN) sobre la misma. La HN consiste en respirar aire empobrecido de oxígeno simulando el entrenamiento en altitud. El objetivo del estudio es determinar la influencia de la HN sobre los dominios de tiempo y frecuencia de la VFC. Sometimos a 13 sujetos sanos (deportistas recreacionales) a dos sesiones de HN. Usamos el simulador iAltitude Trainer v2.7®. La primera mediante un test de tolerancia a la hipoxia (TTH) (10 minutos, 11% O2, equivalente a 5.050 m) y, la segunda, con una exposición intermitente (HNI) (14% O2, 3.250 m) en la que se alternaron periodos de 4 minutos de hipoxia con 4 de normoxia durante 64 minutos. Para el análisis de VFC se utilizó un pulsómetro Polar H10®, la aplicación HRV-elite® y el software Kubios-Standard®. Se tomaron los datos de los 5 minutos previos y posteriores a cada sesión, comparándose estos valores mediante el test de T-student para datos pareados. Ninguna de las variables de los dominios de tiempo (RRmedio, SDNN, rMSSD, pNN50) ni de frecuencia (VLF, LF, HF, LF/HF) de la VFC mostró cambios significativos ante ninguna de las dos situaciones. La HN no provocó modificaciones en los niveles de estrés de estos sujetos, siendo bien tolerada, clínica y electrocardiográficamente. Un test de tolerancia y una sesión de exposición a hipoxia normobárica intermitente no son estímulos suficientes para provocar cambios agudos en la VFC

Heart rate variability (HRV) is a tool capable of analysing and assessing the vegetative activity of the heart in various activities and situations. It consists of measuring the time that elapses between every two heartbeats over a period of time and expressing it in terms of mathematical and statistical equations. Other authors have analysed the influence of different stressors on HRV. In this work we are looking for the action of normobaric hypoxia (NH) on HRV. NH consists of breathing oxygen-depleted air simulating altitude training. The aim of the study is to determine the influence of HN on the time and frequency domains of HRV. We subjected 13 healthy subjects (recreational athletes) to two HN sessions. We used the iAltitude Trainer v2.7® simulator. The first was a hypoxia tolerance test (HTT) (10 minutes, 11% O2, equivalent to 5050m) and the second was an intermittent exposure (HNI) (14% O2, 3250m) in which periods of 4 minutes of hypoxia alternated with 4 minutes of normoxia for 64 minutes. For HRV analysis, a Polar H10® heart rate monitor, the HRV-elite® application and the Kubios-Standard® software were used. Data were taken 5 minutes before and after each session, and these values were compared using the Student ́s t- test for paired data. None of the variables in the time (RRmean, SDNN, rMSSD, pNN50) or frequency (VLF, LF, HF, LF/HF) domains of HRV showed significant changes in either situation. HN did not cause changes in the stress levels of these subjects and was well tolerated, clinically and electrocardiographically. A tolerance test and a session of exposure to intermittent normobaric hypoxia are not sufficient stimuli to cause acute changes in HRV.(AU)

The Effect of Normobaric Hypoxia in Middle- and/or Long-Distance Runners: Systematic Review.

BACKGROUND: The use of normobaric hypoxia can bring benefits to sports performance because it improves haematological parameters and/or physical activity tests. Our objective was to conduct a systematic review so as to analyse the methods used in hypoxia and to detect its effects on middle- and/or long-distance runners. METHODS: Research was conducted using five electronic databases (PubMed, SportDiscus, Cochrane Library, Scopus and PEDro) until December 2021. The methodological quality of the included studies was assessed using the PEDro scale. RESULTS: Having analysed 158 studies, 12 were chosen for the qualitative and quantitative synthesis. A significant improvement on time until exhaustion was detected, and oxygen saturation decreased after the intervention. There were no significant changes in the 3000-metre time trial or in the haematocrit percentage. The changes in percentage of reticulocytes, heart rate, maximal heart rate, lactate concentration and erythropoietin were heterogeneous between the different research studies. CONCLUSION: short exposure (less than 3 h to normobaric hypoxia significantly increases the time to exhaustion). However, longer exposure times are necessary to increase haemoglobin. Altitude and exposure time are highly heterogeneous in the included studies.

Validity and Absolute Reliability of the Cobb Angle in Idiopathic Scoliosis with TraumaMeter Software.

The Cobb angle value is a critical parameter for evaluating adolescent idiopathic scoliosis (AIS) patients. This study aimed to evaluate a software's validity and absolute reliability to determine the Cobb angle in AIS digital X-rays, with two different degrees of experienced observers. Four experts and four novice evaluators measured 35 scoliotic curves with the software on three separate occasions, one month apart. The observers re-measured the same radiographic studies on three separate occasions three months later but on conventional X-ray films. The differences between the mean bias errors (MBE) within the experience groups were statistically significant between the experts (software) and novices (manual) (p < 0.001) and between the novices (software) and novices (manual) (p = 0.005). When measured with the software, the intra-group error in the expert group was MBE = 1.71 ± 0.61° and the intraclass correlation coefficient (ICC (2,1)) = 0.986, and in the novice group, MBE = 1.9 ± 0.67° and ICC (2,1) = 0.97. There was almost a perfect concordance among the two measurement methods, ICC (2,1) = 0.998 and minimum detectable change (MCD95) < 0.4°. Control of the intrinsic error sources enabled obtaining inter- and intra-observer MDC95 < 0.5° in the two experience groups and with the two measurement methods. The computer-aided software TraumaMeter increases the validity and reliability of Cobb angle measurements concerning manual measurement.

Validity and reliability of a computer-assisted system method to measure axial vertebral rotation.

Background: Axial vertebral rotation and Cobb's angle are essential parameters for analysing adolescent idiopathic scoliosis. This study's scope evaluates the validity and absolute reliability of application software based on a new mathematical equation to determine the axial vertebral rotation in digital X-rays according to Raimondi's method in evaluators with different degrees of experience. Methods: Twelve independent evaluators with different experience levels measured 33 scoliotic curves in 21 X-rays with the software on three separate occasions, separated one month. Using the same methodology, the observers re-measured the same radiographic studies three months later but on X-ray films and in a conventional way. Results: Both methods show good validity and reliability, and the intraclass correlation coefficients are almost perfect. According to our results, the software increases 1.7 times the validity and 1.9 times the absolute reliability of axial vertebral rotation on digital X-rays according to Raimondi's method, compared to the conventional manual measurement. Conclusions: The intra-group and inter-group agreement of the measurements with the software shows equal or minor variations than with the manual method, among the different measurement sessions and in the three experience groups. There is almost perfect agreement between the two measurement methods, so the equation and the software may be helpful to increase the accuracy in the axial vertebral rotation assessment.

Muscle oxygenation of the quadriceps and gastrocnemius during maximal aerobic effort / Oxigenación muscular de cuádriceps y gastrocnemio durante el esfuerzo aeróbico máximo / Oxigenação muscular de quadríceps e gastrocnêmio durante o esforço aeróbico máximo

ABSTRACT Introduction: Near infrared spectroscopy (NIRS) is a non-invasive technique that is used in the assessment of tissue oxygenation and the monitoring of physical activity. Objective: To determine the influence of sexual, anthropometric and ergospirometric factors on muscle oxygenation of the quadriceps and gastrocnemius, obtained by NIRS during a stress test. Methods: Twenty healthy subjects participated in this study (10 women). Two Humon Hex® devices were placed on the dominant side of the quadriceps and gastrocnemius muscles to measure muscle oxygen saturation (SmO2). The stress test was performed on a treadmill with electrocardiographic control and measurement of oxygen consumption. SmO2 was obtained at rest and after maximum effort during the stress test. In addition, the height, weight, skinfold and waist contour were measured. Bioimpedance was used to obtain the percentages of fat mass and muscle mass, which were used to calculate the relative fat mass (RFM). Results: The SmO2 of both muscles at rest is higher in males than in females. At maximum effort, the SmO2 of the quadriceps is similar in both groups. The SmO2 of both muscles is positively related to height, body mass, percentage of mass muscle and waist contour, and negatively with percentage of mass fat, RFM and skinfold thickness. The negative correlation between fat percentage and oxygen saturation is more evident in females. It was observed that the variables that quantify maximum effort are not related to the SmO2 values, except for the correlation between HR max and SmO2 of the gastrocnemius muscle in males. Conclusion: The SmO2 of recreational athletes is influenced by the location of the device and the fat mass of the subjects. The biggest differences between the sexes are in the gastrocnemius muscle. Level of Evidence II; Diagnostic Studies - Investigating a Diagnostic Test .

RESUMEN Introducción: La espectroscopia de infrarrojo cercano (NIRS) es una técnica no invasiva usada en la evaluación de la oxigenación tisular y en la monitorización de la actividad física. Objetivos: Determinar la influencia de factores sexuales, antropométricos y ergoespirométricos sobre la oxigenación muscular de cuádriceps y del gastrocnemio, obtenidos por NIRS durante un test de esfuerzo. Métodos: Participaron en este estudio 20 individuos saludables (10 mujeres). Se colocaron dos dispositivos Humon Hex® en el lado dominante de los músculos cuádriceps y gastrocnemio para medir la saturación de oxígeno muscular (SmO2). El test de esfuerzo fue realizado en una cinta ergométrica con control electrocardiográfico y medición del consumo de oxígeno. La SmO2 fue obtenida en reposo y después de esfuerzo máximo durante el test. Además, fueron medidos altura, peso, pliegues cutáneos y contorno de la cintura. Fue usada bioimpedancia para obtener los porcentuales de masa grasa y masa muscular, que fueron usados para calcular la masa grasa relativa (MGR). Resultados: La SmO2 de ambos músculos en reposo es mayor en hombres que en mujeres. En el esfuerzo máximo la SmO2 del cuádriceps es semejante en los dos grupos. La SmO2 de ambos músculos es positivamente relacionada con altura, masa corporal, porcentual de masa muscular y contorno de la cintura y negativamente relacionada con el porcentaje de masa grasa, MGR y espesor de los pliegues cutáneos. La correlación negativa entre el porcentual de grasa y la saturación de oxígeno es más evidente en las mujeres. Se observó que variables que cuantifican el esfuerzo máximo no está relacionadas con los valores SmO2, excepto por la correlación entre FCmáx y SmO2 del músculo gastrocnemio en sexo masculino. Conclusión: La SmO2 de los atletas recreativos es influenciada por la localización del dispositivo y por la masa grasa de los individuos. Las mayores diferencias entre los sexos están en el músculo gastrocnemio. Nivel de Evidencia II; Estudios diagnósticos - Investigación de un examen para diagnóstico .

RESUMO Introdução: A espectroscopia de infravermelho próximo (NIRS) é uma técnica não invasiva usada na avaliação da oxigenação tecidual e no monitoramento da atividade física. Objetivos: Determinar a influência de fatores sexuais, antropométricos e ergoespirométricos sobre a oxigenação muscular do quadríceps e do gastrocnêmio obtidos por NIRS durante um teste de esforço. Métodos: Participaram deste estudo 20 indivíduos saudáveis (10 mulheres). Dois dispositivos Humon Hex® foram colocados no lado dominante dos músculos quadríceps e gastrocnêmio para medir a saturação de oxigênio muscular (SmO2). O teste de esforço foi realizado em uma esteira com controle eletrocardiográfico e mensuração do consumo de oxigênio. A SmO2foi obtida em repouso e depois de esforço máximo durante o teste. Além disso, foram medidos estatura, peso, dobras cutâneas e contorno da cintura. A bioimpedância foi usada para obter os percentuais de massa gorda e massa muscular, que foram usados para calcular a massa gorda relativa (MGR). Resultados: A SmO2de ambos os músculos em repouso é maior em homens do que em mulheres. No esforço máximo, a SmO2do quadríceps é semelhante nos dois os grupos. A SmO2de ambos os músculos é positivamente relacionada com estatura, massa corporal, percentual de massa muscular e contorno da cintura e negativamente relacionada com a porcentagem de massa gorda, MGR e espessura das dobras cutâneas. A correlação negativa entre o percentual de gordura e a saturação de oxigênio é mais evidente nas mulheres. Observou-se que variáveis que quantificam o esforço máximo não estão relacionadas com os valores SmO2, exceto pela correlação entre FCmáx e SmO2do músculo gastrocnêmio no sexo masculino. Conclusão: A SmO2dos atletas recreativos é influenciada pela localização do dispositivo e pela massa gorda dos indivíduos. As maiores diferenças entre os sexos estão no músculo gastrocnêmio. Nível de Evidência II; Estudos diagnósticos - Investigação de um exame para diagnóstico .

Estrés cardiaco asociado a la realización de una formación acrobática paracaidista / Cardiac stress associated to the realization of an acrobatic skydiver formation

INTRODUCCIÓN: El paracaidismo acrobático es una actividad de alto riesgo. Este riesgo y la dificultad de las maniobras son factores estresantes que modifican la respuesta cardiaca. Nuestro objetivo es analizar el trazado electrocardiográfico y la evolución de la frecuencia cardiaca (FC) durante esta actividad paracaidista creando una figura de alta dificultad. MÉTODO: Colocamos un monitor electrocardiográfico Nuubo a dos paracaidistas experimentados de la Patrulla Acrobática Paracaidista del Ejército del Aire (PAPEA) durante la ejecución de una formación acrobática en la que cuatro paracaidistas se unen durante el vuelo creando una figura denominada "diamante". Analizamos el electrocardiograma (ECG) durante todo el ejercicio y recogimos la FC en las siguientes fases: 1.- Subiendo al avión; 2.- Despegando; 3.- Antes de saltar; 4.- Preparando la figura; 5.- En formación y 6.- Tomando tierra. Se repitió cinco veces, obteniéndose la media de cada saltador. Previamente se realizó un ECG en reposo y una prueba de esfuerzo máxima (PE) en tapiz rodante. RESULTADOS: Ambos saltadores consiguen la mayor FC mientras vuelan preparando la formación (165 y 143 lat/min), supone el 87% y 77% de la FC máxima alcanzada en la PE. No se recogen FC inferiores a 95 pulsaciones en ninguna fase ni salto. Cada saltador tiene un tipo de respuesta, según le afecte el momento del despegue. En uno la FC aumenta paulatinamente hasta ella llega al pico máximo cuando están en formación y en el otro aparece otro pico, que se repite en los cinco saltos, coincidiendo con el despegue. En el ECG sólo se han observado episodios continuados de taquicardias sinusales. CONCLUSIONES: Concluimos que el estrés cardiaco producido por la realización de este tipo de ejercicios se manifiesta por aumentos importantes de la frecuencia cardiaca, en torno al 80% de la frecuencia cardiaca máxima, sin otras alteraciones electrocardiográficas

INTRODUCTION: Acrobatic skydiving is considered a high risk activity. This risk and the difficulty of the maneuvers are stressors that modify the cardiac activity. Our aim is to analyze the electrocardiographic tracing and the evolution of the heart rate during this paratrooper activity, creating a figure of high difficulty. METHOD: We put a Nuubo electrocardiographic monitor on two experienced paratroopers members of the Acrobatic Patrooper Patrol of the Air Force (PAPEA) during the execution of an acrobatic exercise, called "diamond", in which four parachutists are attached during the flight. We analyzed the electrocardiogram (ECG) during the whole activity and we got the heart rate (HR) in the following phases: 1.- Up to the aircraft; 2.-Taking off; 3.- Before jumping; 4.- Preparing the figure; 5.- Formation flight and 6.- Landing. They jumped five times, obtaining the average of each jumper. Previously we made them an ECG at rest and maximal treadmill stress test (ST ).RESULTS: Both jumpers get the largest HR while they fly preparing the formation (165 and 143 beats/min), it is 87% and 77% of the max HR reached in ST. Beats under 95 b/min are not registered in any stage or jump. Each jumper has a different response, depending on the effect that the take-off has on him. In one of them, HR increases gradually until it reaches the maximum peak when they are in formation, and on the other jumper it appears another peak, that is repeated in the five jumps, coinciding with the taking off. There is no other ECG alterations. CONCLUSIONS: We conclude that cardiac stress caused by carrying out this type of exercises is manifested by significant increases in heart rate, around 80% of the maximum heart rate, without other electrocardiographic abnormalities

Fuerza isocinética y test de salto vertical en paracaidistas acrobáticos / Isokinetic strength and vertical jump test in acrobatic skydivers

Introducción: Las rodillas de los paracaidistas pueden sufrir lesiones durante la toma de tierra que se pueden prevenir con una adecuada fuerza muscular. Esta fuerza se puede evaluar de manera directa con dinamómetros isocinéticos y con métodos indirectos mediante el test de salto vertical. Objetivo: El objetivo del estudio fue determinar y analizar, en paracaidistas profesionales, las relaciones entre los valores fuerza isocinética máxima de cuádriceps e isquiosurales con la altura y el tiempo de vuelo en saltos verticales. Material y método: Valoramos a los catorce paracaidistas pertenecientes a la Patrulla Acrobática Paracaidista del Ejército del Aire mediante un dinamómetro isocinético (a 60º/s y 180º/s) tanto para el trabajo concéntrico como excéntrico, obteniéndose los picos máximos de fuerza y las ratios isquiosurales/cuádriceps. Evaluamos, sobre una plataforma de contacto, los siguientes saltos verticales: Squat Jump, Counter Movement Jump y Abalakov Jump. Resultados: Los resultados indican que los picos de fuerza máxima de la musculatura flexo-extensora de la rodilla son mayores en modalidad excéntrica, y en el equipo masculino. Las ratios isquiosurales/cuádriceps muestran un predominio de los primeros. Abalakov Jump es el salto donde mayor altura y tiempo de vuelo se consigue. Existe una correlación positiva entre el tiempo de vuelo de todos los saltos y la fuerza concéntrica del cuádriceps. La altura de salto por el peso corporal (Trabajo = Kg x m) se correlaciona con los picos de fuerza concéntrica y excéntrica del cuádriceps. La relación es mayor en la velocidad más alta. La fuerza excéntrica de isquiosurales no se correlaciona con la altura de vuelo, pero sí la fuerza concéntrica. Conclusiones: Podemos concluir que las rodillas de los paracaidistas presentan un predominio en la fuerza de los isquiosurales, lo que se considera positivo para la actividad que realizan ya que contribuye a mejorar la estabilidad de la rodilla y que hay altas correlaciones entre los picos de fuerza isocinético y el trabajo realizado en los saltos verticales

Introduction: Knees of the parachutists can suffer injuries during the landing that can be avoided with a correct muscular strength. This strength is posible to be evaluated of direct way with isokinetic dynanometers and indirect methods using the test of vertical jump. Objective: The aim of this study was to determine and analyze, in professional skydivers, the relationship between the values of isokinetic force of quadriceps and hamstrings with height and time of flight in vertical jumps. Material and methods: We studied the fourteen paratroopers belonging to the (patrol acrobatic jumper of the air force) using an isokinetic dynamometer (60°/s and 180°/s) both for concentric work as eccentric, obtaining the peaks maximum of strength and hamstrings/quadriceps ratios. Evaluate, on a platform of contact, the following vertical jumps: Abalakov Jump and Squat Jump, Counter Movement Jump. Results: The results indicate that the peaks of maximum strength of flexor and extensor muscles of the knee are greater in eccentric mode, and the men’s team. Hamstrings/quadriceps ratios show a predominance of the first. AJ is the jump where greater height and time of flight is achieved. There is a positive correlation between the flight time of all jumps and concentric quadriceps strength. The height of jump by body weight (Work = Kg x m) correlates with the peaks of concentric and eccentric strength of the quadriceps. The ratio is higher in the higher speed. The eccentric strength of hamstrings does not correlate with the height of flight, but the concentric strength. Conclusions: We can conclude that the knees of the skydivers have a predominance of the hamstrings what is considered positive for the activity carried out, since it helps to improve the stability of the knee and that there are high correlations between the peaks of force isokinetic and the work done in the jumps vertical

Contraindicaciones para la práctica deportiva. Documento de consenso de la Sociedad Española de Medicina del Deporte (SEMED-FEMEDE) / Contraindications of sports practice. Consensus document of the SPANISH Society of Sports Medicine (SEMED-FEMEDE)

La función principal de la medicina del deporte es el cuidado de la salud del deportista, no solo desde el punto de vista del tratamiento, sino también desde el de la prevención. Los reconocimientos médicos para la aptitud deportiva, una de las atribuciones principales de esta especialidad, están destinados a descubrir patologías, enfermedades o alteraciones que pueden afectar a la salud, y abarcan desde las situaciones que pueden desencadenar incidentes mortales hasta las que, sin poner en riesgo la vida, pueden afectar la salud o el rendimiento del deportista. La realización adecuada de reconocimientos para el deporte implica el diagnóstico de problemas médicos que deben analizarse, entre otros puntos de vista, desde la óptica de la aptitud para la práctica deportiva, y el médico encargado debe disponer de una guía que le oriente sobre la decisión de autorizar o no la práctica de deporte, y en caso de no autorización, la temporalidad de esta y el riesgo asumible de participación en algunos deportes. Las contraindicaciones para la práctica deportiva mejor conocidas son las de origen cardiovascular, tratadas extensamente en la literatura, pero también existen contraindicaciones del resto de aparatos y sistemas del organismo, entendiendo que el deportista es un ser completo y que el ejercicio físico afecta a todo su conjunto. Este documento, además de recoger dichas contraindicaciones, analiza los aspectos legales que afectan a los profesionales en los que recae la responsabilidad de realizar los reconocimientos y los aspectos documentales que les son propios

Main purpose of sports medicine is reaching the health care of the athlete, not only from the point of view of treatment, but also from the point of view of prevention. The performance of preparticipation medical sports evaluation, one of the main attributions of this specialty, is aimed at the discovery of pathologies, diseases or alterations that may affect health. They might range from situations that can trigger deadly incidents, to those without putting life at risk, can affect the health or performance of the athlete. Adequate implementation of preparticipation medical sports evaluation implies the diagnosis of medical problems that must be analyzed, from other points of view such as the perspective of fitness for sport practice. In addition, the doctor in charge must have a guide for clearance for sports practice. In case of non-authorization, time for non-sports activities must be recommended in order to decrease injury risks. Cardiovascular pathologies are the best known contraindications in sport practice, treated extensively in the literature. However, there are also contraindications secondary to problems or issues of the rest of apparatus organs and systems of the organism, knowing that the athlete represents an entity in which physical exercise affects all their sets. This document highlights those contraindications already discussed above and analyzes the legal aspects of sports practice contraindications. Medical professionals are responsible for managing the pre-participation medical sports evaluation as well as the documentary aspects that support it

Sex differences in the effort indicators during cardiopulmonary resuscitation manoeuvres on manikins.

The aims of this study were to examine sex differences in college students while they performed cardiopulmonary resuscitation (CPR) on a manikin for 20 min in (a) objective and subjective effort indicators and (b) to analyse the influence of potential confounders (age, BMI and cardiorespiratory fitness) on these sex differences. Sixty-three participants were recruited. Participants performed 20 min of CPR on a manikin. During the CPR trial, percentages of maximal heart rate levels were higher in women than in men (P<0.05) and perceived exertion increased significantly in both sexes over time (P=0.05); furthermore, at the last two time points analysed, women scored higher than men (P<0.05). However, these sex differences disappeared when controlling for age, BMI and cardiorespiratory fitness. In conclusion, indicators of exertion during CPR are higher in women than in men, but these sex differences are because of BMI and differences in physical fitness conditions.

Influencia del consumo máximo de oxígeno y de la fuerza del tren superior en la calidad de la reanimación cardiopulmonar realizada por universitarios jóvenes / Influence of maximal oxygen uptake and maximum strength of the upper body of university students in the ability to perform quality cardiopulmonary resuscitation

Objetivos: 1) analizar por sexo el porcentaje medio de la frecuencia cardiaca máxima (PFCM) alcanzado en 5 minutos de reanimación cardiopulmonar (RCP); 2) examinar la asociación del índice de masa corporal (IMC) y la forma física con la proporción de compresiones torácicas externas (CTE) correctas; y 3) establecer los puntos de corte óptimos de consumo máximo de oxígeno (VO2max), y fuerza muscular en brazos (kg) para realizar CTE correctas durante 5 minutos. Métodos: Estudio cuasi-experimental que incluyo 63 estudiantes universitarios. Se determinaron IMC, capacidad cardiorrespiratoria y fuerza muscular manual. Tras formación previa, realizaron Reanimación Cardiopulmonar en maniqui durante 5 minutos. Resultados: El PFCM alcanzado fue 64,2 en hombres y 76,9 en mujeres (p = <0,001). El porcentaje medio de CTE correctas fue mayor en participantes con normo peso/sobrepeso, alto nivel de VO2max y fuerza manual. IMC, VO2max y fuerza manual fueron predictores de adecuada profundidad de compresiones en modelos de regresión lineal múltiple controlando por edad y sexo. En curva característica de operación del receptor (ROC), el área bajo la curva normal para predecir CTE correctas fue 0,862 para VO2max, y 0,872 para la fuerza manual (puntos de corte de 44,5 ml/Kg/min y de 30,22 Kg respectivamente). Conclusiones: Las características antropométricas y la forma física influyen en la realización de CTE correctas en una RCP. Nuestros datos sugieren que una adecuada forma física aumentara la capacidad de los reanimadores para realizar RCP-Básica

Background: It has been hypothesized that fitness and body mass index of the rescuers are predictors of the adequate of external chest compressions. The aims of this study were to: 1) analyze by sex the percentage of maximum heart rate (%EMHR) reached in 5 minutes of cardiopulmonary resuscitation (CPR); 2) examine the influence of both body mass index and fitness on predicting adequate chest compressions; and 3) estimate the optimal levels of them in 5 minutes of cardiopulmonary resuscitation (CPR). Methods: Quasi-experimental study involving sixty three subjects were recruited from University of Castilla-La Mancha, Spain. We determined weight, height, cardiorespiratory (maximal oxygen uptake -VO2max) and muscular fitness (handgrip-test). After previous training, participants performed cardiopulmonary resuscitation on a mannequin during 5 minutes. Results: The %EMHR achieved was 64.2 in men and 76.9 in women. The mean percentage of adequate chest compressions was higher on the participants with normal weight/overweight (p<0.001), and on those who had a low level of cardiorespiratory (p=0.004) and muscular fitness (p=0.011). Body mass index, cardiorespiratory and muscular fitness are predictors of correct compression depth and chest compression when controlling for age and sex. The best cut-off points for predicting successful chest compressions were 44.45 ml/kg/min for VO2max, and 30.22 kg for muscular fitness. Conclusions: Anthropometric and physical fitness conditions may influence the external chest compressions performance. Our data suggest that rescuers should improve their fitness in order to increase their capacity to provide cardiopulmonary resuscitation

Seguimiento longitudinal de la evolución en la condición aeróbica en jóvenes futbolistas / Longitudinal tracing of aerobic condition's evolution in young soccer players

ObjetivoEl objetivo del presente estudio fue determinar el comportamiento de los principales factores condicionantes de la condición aeróbica en jóvenes futbolistas (15–18 años).ProcedimientoPara ello, se estudió a una muestra de 79 jugadores pertenecientes a los equipos inferiores del Albacete Balompié y que habían pasado al menos 2 pruebas de esfuerzo en el periodo de las temporadas 00/01–07/08.Se obtuvieron datos sobre el consumo máximo de oxígeno (VO2max), la FC máxima, la velocidad máxima alcanzada en el momento del máximo consumo de oxígeno y el porcentaje de VO2max al que se producía el umbral anaeróbico.ConclusionesEl consumo máximo de oxígeno relativo como máximo exponente de la potencia aeróbica de un sujeto no sufre modificaciones significativas durante el periodo de edad de los 15–18 años.La economía de carrera medida mediante la capacidad de generar velocidad (velocidad de desplazamiento) a una intensidad dada mejora durante la pubertad, para estabilizarse a partir de los 17 años.La FC máxima se reduce durante la adolescencia a razón de 7–8 pulsaciones cada 5 años.No existen diferencias entre los porcentajes de VO2max a los que los jugadores de 15–18 años experimentan su umbral anaeróbico(AU)

GoalThe aim of the present study was to determine the behaviour of the main factors of aerobic condition in young soccer players (15–18 years).ProcessFor this, we studied 79 subjects who belong to Albacete Balompié's young teams. These players passed two effort tests at least during the period (00/01–07/08).We obtained data about the maximum oxygen intake (VO2max), maximum heart rate, maximum speed at the moment of VO2max and the percentage of VO2max when the anaerobic threshold happenesConclusionsMaximal oxygen intake like exponent of aerobic power doesn't experiment significant changes during ages 15 to 18.Run's economy improves during puberty and stabilizes as of 17 years.Maximal heart rate decrease during adolescence us 7–8 beat each 5 years.There aren't differences between VO2max's percentages which 15–18 players experiment their anaerobic threshold(AU)

La "medicina" del Ejercicio Físico

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