RESUMEN
Functional beverages based on almonds and olive oil and enriched with α-tocopherol and docosahexaenoic acid (DHA) could be useful in modulating oxidative stress and enhancing physical performance in sportsmen. The aim of this work was to evaluate the effects of supplementation with functional beverages on physical performance, plasma and erythrocyte fatty acids' and polyphenol handling, oxidative and nitrative damage, and antioxidant and mitochondrial gene expression in young and senior athletes. Athletes performed maximal exercise tests before and after one month of dietary supplementation and blood samples were taken immediately before and one hour after each test. The beverages did not alter performance parameters during maximal exercise. Supplementation increased polyunsaturated and reduced saturated plasma fatty acids while increasing the DHA erythrocyte content; it maintained basal plasma and blood polyphenol levels, but increased the blood cell polyphenol concentration in senior athletes. Supplementation protects against oxidative damage although it enhances nitrative damage in young athletes. The beverages enhance the gene expression of antioxidant enzymes in peripheral blood mononuclear cells after exercise in young athletes.
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Bebidas/análisis , Ácidos Docosahexaenoicos/farmacología , Aceite de Oliva/farmacología , Estrés Oxidativo/efectos de los fármacos , Aceites de Plantas/farmacología , Vitamina E/farmacología , Adulto , Envejecimiento , Rendimiento Atlético , Biomarcadores , Suplementos Dietéticos , Ácidos Docosahexaenoicos/administración & dosificación , Ácidos Docosahexaenoicos/química , Prueba de Esfuerzo/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Aceite de Oliva/administración & dosificación , Aceite de Oliva/química , Aceites de Plantas/administración & dosificación , Aceites de Plantas/química , Vitamina E/administración & dosificación , Vitamina E/química , Adulto JovenRESUMEN
The purpose of genital examination (GE) during the Pre-participation Physical Examination (PPE) is to identify the state of maturity, and rule out any genital pathology. To describe genital anomalies (GA) and estimate the awareness of GE in young football players. A descriptive, cross-sectional study was conducted in 280 elite football players from the results of PPE over two seasons. There was a detection rate of 5.4% GA, with varicocele being 3.2%, and of which only 13% were aware of their condition. Although this study shows a low incidence of genital abnormality in the study population, only 13% were aware of the GE prior to assessment. These findings demonstrate a low incidence of GA in this population. While GE is recommended during PPE, it is not a routine practice performed by family doctors or sports medicine specialists. This article attempts to raise awareness of the importance of GE in PPE as a preventive health strategy.
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Genitales Masculinos/anomalías , Adolescente , Niño , Anomalías Congénitas/epidemiología , Estudios Transversales , Fútbol Americano , Humanos , Incidencia , Masculino , Prevalencia , Varicocele/epidemiologíaRESUMEN
INTRODUCTION: The discovery of vitamin D muscle receptors in the last few years suggested a significant role in muscle tissue, pointing out athletes as a special group. Specific data are scarce. AIM: The main aim of the current paper was to provide, for the first time, comparable data about vitamin D status in elite Spanish athletes by sport, age, season and training environment. METHODS: Four hundred and eight elite athletes with a mean age of 22.8 ± 8.4 years were recruited from the High-performance sport centre in Barcelona for this cross-sectional study. Athletes from 34 different sports modalities were analysed. Data were available for vitamin D status, training environment, seasonality and number of medical visits. All data were analysed using SPSS version 18.0. RESULTS: Mean 25(OH)D of all athletes was 56.7 ± 23.4 nmol/L. Approximately 82% of the athletes were below the optimal levels, (< 75nmol/l), 45% had moderate deficient levels (< 50 nmol/L) and 6% had severe deficiency (< 27.5 nmol/L). We have observed a steady increase in 25(OH)D concentrations with increasing age (p < 0.01) Highest levels were observed in those subjects training outdoors compared with those training indoor (p.
INTRODUCCIÓN: En los últimos años, el descubrimiento de receptores musculares para la vitamina D sugiere un papel significativo de esta vitamina en el tejido muscular, adquiriendo una relevancia especial en deportistas. No existen apenas datos disponibles acerca de las concentraciones de vitamina D en deportistas de élite Españoles. OBJETIVO: El objetivo del presente trabajo ha sido analizar y proporcionar datos comparables sobre el estado de vitamina D de atletas de élite españoles y la influencia de factores como la edad, la estación del año o el lugar de entrenamiento. MÉTODOS: Cuatrocientos ocho atletas de élite pertenecientes al centro de alto rendimiento de San Cugat del Vallés, en Barcelona, fueron seleccionados con toma de datos transversal. La edad media fue de 22,8 ± 8,4 años con un total de 34 modalidades deportivas diferentes. Entre las variables analizadas se obtuvieron las concentraciones plasmáticas de vitamina D, el número de visitas médicas anuales, la toma de suplementos, la estación del año y el lugar de entrenamiento. La estadística se realizó con el programa SPSS versión 19.0. RESULTADOS: La concentración media de 25(OH)D de la muestra total fue de 56.7 ± 23.4 nmol/L. Aproximadamente el 82% de los atletas obtuvieron concentraciones sanguíneas por debajo de los niveles óptimos (< 75nmol/L). Dentro de estos, el 45% presentó deficiencia moderada (< 50 nmol/L ) mientras que un 6% deficiencia severa (< 27,5 nmol/L). Se observó un aumento lineal de las concentraciones de 25(OH)D con la edad (p < 0,01 ) y concentraciones más altas en las modalidades deportivas con entrenamiento al aire libre (tenis, natación piscina descubierta ) en comparación con los que entrenan bajo techo (natación piscina cubierta, balonmano..) (p < 0,01). Incluso durante los meses de verano, el 87% de los atletas obtuvieron concentraciones insuficientes de vitamina D en su mayoría los que entrenan en interior. Señalaron no tomar suplementos vitamínicos. CONCLUSIONES: Existe una alta prevalencia de insuficiencia de vitamina D entre los deportistas de élite españoles. El entrenamiento al aire libre podría garantizar la suficiencia de vitamina D y las diferencias encontradas entre las distintas modalidades deportivas se deben tener en cuenta para futuras investigaciones. Los resultados contribuyen a identificar la necesidad de optimizar los niveles de vitamina D en deportistas de élite.
Asunto(s)
Adaptación Fisiológica , Deportes/fisiología , Deficiencia de Vitamina D/epidemiología , Adolescente , Adulto , Estudios Transversales , Femenino , Humanos , Masculino , Prevalencia , Estaciones del Año , España , Vitamina D/sangre , Deficiencia de Vitamina D/sangre , Adulto JovenRESUMEN
OBJECTIVE: Physical exercise is capable of enhancing or suppressing the immune response depending on the intensity and duration of exercise. This study investigated how exercise intensity influences the lymphocyte antioxidant response and the induction of cellular oxidative damage. DESIGN: Eighteen voluntary male pre-professional soccer players participated in this study. Sportsmen played a 60 min training match, and were divided into three groups depending on the intensity degree during the match: low, medium and high intensities. MEASUREMENTS: Malondialdehyde (MDA), vitamins C and E and haem oxygenase-1 (HO-1) gene expression were measured in lymphocytes. Reactive oxygen species (ROS) production was determined in lymphocytes and neutrophils. RESULTS: Lymphocyte MDA levels and H(2)O(2) production were significantly increased in the group which performed the most intense exercise. Neutrophil counts and ROS production increased progressively with the exercise intensity. Vitamin C significantly decreased after exercise in the highest-intensity group in comparison with initial values, whereas vitamin E levels significantly increased in the medium and high-intensity groups. HO-1 gene expression significantly increased in the medium and high-intensity groups. CONCLUSIONS: Exercise intensity affects the lymphocyte and neutrophil oxidant/antioxidant balance, but only exercise of high intensity induces lymphocyte oxidative damage.
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Antioxidantes/metabolismo , Ejercicio Físico/fisiología , Peróxido de Hidrógeno/metabolismo , Linfocitos/metabolismo , Fútbol/fisiología , Adulto , Análisis de Varianza , Ácido Ascórbico/metabolismo , Humanos , Masculino , Malondialdehído/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Vitamina E/metabolismo , Adulto JovenRESUMEN
Exercise-induced (EI) hypersensitivity disorders are significant problems for both recreational and competitive athletes. These include EI-asthma, EI-bronchoconstriction, EI-rhinitis, EI-anaphylaxis and EI-urticaria. A group of experts from the European Academy of Allergology and Clinical Immunology and the American Academy of Allergy Asthma and Immunology met to discuss the pathogenesis of these disorders and how to diagnose and treat them, and then to develop a consensus report. Key words (exercise with asthma, bronchoconstriction, rhinitis, urticaria or anaphylaxis) were used to search Medline, the Cochrane database and related websites through February 2008 to obtain pertinent information which, along with personal reference databases and institutional experience with these disorders, were used to develop this report. The goal is to provide physicians with guidance in the diagnosis, understanding and management of EI-hypersensitivity disorders to enable their patients to safely return to exercise-related activities.
Asunto(s)
Ejercicio Físico , Hipersensibilidad/etiología , Anafilaxia/etiología , Asma Inducida por Ejercicio/etiología , Humanos , Hipersensibilidad/diagnóstico , Hipersensibilidad/terapia , Rinitis/etiología , Síndrome , Urticaria/etiologíaRESUMEN
AIM: The aims of part II is to review the current recommended treatment of exercise-induced asthma (EIA), respiratory and allergic disorders in sports, to review the evidence on possible improvement of performance in sports by asthma drugs and to make recommendations for their treatment. METHODS: The literature cited with respect to the treatment of exercise induced asthma in athletes (and in asthma patients) is mainly based upon the systematic review given by Larsson et al. (Larsson K, Carlsen KH, Bonini S. Anti-asthmatic drugs: treatment of athletes and exercise-induced bronchoconstriction. In: Carlsen KH, Delgado L, Del Giacco S, editors. Diagnosis, prevention and treatment of exercise-related asthma, respiratory and allergic disorders in sports. Sheffield, UK: European Respiratory Journals Ltd, 2005:73-88) during the work of the Task Force. To assess the evidence of the literature regarding use of beta(2)-agonists related to athletic performance, the Task Force searched Medline for relevant papers up to November 2006 using the present search words: asthma, bronchial responsiveness, exercise-induced bronchoconstriction, athletes, sports, performance and beta(2)-agonists. Evidence level and grades of recommendation were assessed according to Sign criteria. RESULTS: Treatment recommendations for EIA and bronchial hyper-responsiveness in athletes are set forth with special reference to controller and reliever medications. Evidence for lack of improvement of exercise performance by inhaled beta(2)-agonists in healthy athletes serves as a basis for permitting their use. There is a lack of evidence of treatment effects of asthma drugs on EIA and bronchial hyper-responsiveness in athletes whereas extensive documentation exists in treatment of EIA in patients with asthma. The documentation on lack of improvement on performance by common asthma drugs as inhaled beta(2)-agonists with relationship to sports in healthy individuals is of high evidence, level (1+). CONCLUSIONS: Exercise induced asthma should be treated in athletes along same principles as in ordinary asthma patients with relevance to controller and reliever treatment after careful diagnosis. There is very high level of evidence for the lack of improvement in athletic performance by inhaled beta2-agonists.
Asunto(s)
Asma Inducida por Ejercicio/tratamiento farmacológico , Hiperreactividad Bronquial/tratamiento farmacológico , Doping en los Deportes , Hipersensibilidad/tratamiento farmacológico , Administración por Inhalación , Agonistas Adrenérgicos beta/uso terapéutico , Comités Consultivos , Antiasmáticos/uso terapéutico , Asma Inducida por Ejercicio/epidemiología , Asma Inducida por Ejercicio/fisiopatología , Hiperreactividad Bronquial/epidemiología , Hiperreactividad Bronquial/fisiopatología , Directrices para la Planificación en Salud , Humanos , Hipersensibilidad/epidemiología , Hipersensibilidad/fisiopatología , Ensayos Clínicos Controlados Aleatorios como Asunto , Sociedades Médicas , Medicina DeportivaRESUMEN
AIMS: To analyze the changes in the prevalence of asthma, bronchial hyperresponsiveness (BHR) and allergies in elite athletes over the past years, to review the specific pathogenetic features of these conditions and to make recommendations for their diagnosis. METHODS: The Task Force reviewed present literature by searching Medline up to November 2006 for relevant papers by the search words: asthma, bronchial responsiveness, EIB, athletes and sports. Sign criteria were used to assess level of evidence and grades of recommendation. RESULTS: The problems of sports-related asthma and allergy are outlined. Epidemiological evidence for an increased prevalence of asthma and BHR among competitive athletes, especially in endurance sports, is provided. The mechanisms for development of asthma and bronchial hyperresponsiveness in athletes are outlined. Criteria are given for the diagnosis of asthma and exercise induced asthma in the athlete. CONCLUSIONS: The prevalence of asthma and bronchial hyperresponsiveness is markedly increased in athletes, especially within endurance sports. Environmental factors often contribute. Recommendations for the diagnosis of asthma in athletes are outlined.
Asunto(s)
Asma Inducida por Ejercicio , Hiperreactividad Bronquial , Hipersensibilidad , Medicina Deportiva , Comités Consultivos , Animales , Asma Inducida por Ejercicio/diagnóstico , Asma Inducida por Ejercicio/epidemiología , Asma Inducida por Ejercicio/etiología , Asma Inducida por Ejercicio/fisiopatología , Hiperreactividad Bronquial/diagnóstico , Hiperreactividad Bronquial/epidemiología , Hiperreactividad Bronquial/etiología , Hiperreactividad Bronquial/fisiopatología , Diagnóstico Diferencial , Humanos , Hipersensibilidad/epidemiología , Hipersensibilidad/etiología , Prevalencia , Sociedades MédicasRESUMEN
BACKGROUND: The prevalence of asthma and bronchial hyper-responsiveness is greater in elite athletes than in the general population, and its association with mild airway inflammation has recently been reported. OBJECTIVE: To study the relationship between the type of sport practised at the highest levels of competition (on land or in water) and sputum induction cell counts in a group of healthy people and people with asthma. MATERIAL AND METHODS: In total, 50 athletes were enrolled. Medical history, results of methacholine challenge tests and sputum induced by hypertonic saline were analysed RESULTS: Full results were available for 43 athletes, who were classified by asthma diagnosis and type of sport (land or water sports). Nineteen were healthy (10 land and 9 water athletes) and 24 had asthma (13 land and 11 water athletes). Although the eosinophil counts of healthy people and people with asthma were significantly different (mean difference 3.1%, 95% CI 0.4 to 6.2, p = 0.008), analysis of variance showed no effect on eosinophil count for either diagnosis of asthma or type of sport. However, an effect was found for neutrophil counts (analysis of variance: F = 2.87, p = 0.04). There was also a significant correlation between neutrophil counts and both duration of training and bronchial hyper-responsiveness among athletes exposed to water (Spearman's rank correlations, 0.36 and 0.47, p = 0.04 and 0.04, respectively). CONCLUSIONS: Elite athletes who practice water sports have mild neutrophilic inflammation, whether or not asthma is present, related to the degree of bronchial hyper-reactivity and the duration of training in pool water.
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Asma/fisiopatología , Hiperreactividad Bronquial/fisiopatología , Neutrófilos/metabolismo , Aptitud Física/fisiología , Deportes/fisiología , Adulto , Análisis de Varianza , Pruebas de Provocación Bronquial , Femenino , Humanos , Inflamación/fisiopatología , Masculino , Pruebas Cutáneas , Espirometría , Esputo/química , AguaRESUMEN
OBJECTIVE: To assess which of the equations used to estimate mechanical power output for a wide aerobic range of exercise intensities gives the closest value to that measured with the SRM training system. METHODS: Thirty four triathletes and endurance cyclists of both sexes (mean (SD) age 24 (5) years, height 176.3 (6.6) cm, weight 69.4 (7.6) kg and Vo(2)max 61.5 (5.9) ml/kg/min) performed three incremental tests, one in the laboratory and two in the velodrome. The mean mechanical power output measured with the SRM training system in the velodrome tests corresponding to each stage of the tests was compared with the values theoretically estimated using the nine most referenced equations in literature (Whitt (Ergonomics 1971;14:419-24); Di Prampero et al (J Appl Physiol 1979;47:201-6); Whitt and Wilson (Bicycling science. Cambridge: MIT Press, 1982); Kyle (Racing with the sun. Philadelphia: Society of Automotive Engineers, 1991:43-50); Menard (First International Congress on Science and Cycling Skills, Malaga, 1992); Olds et al (J Appl Physiol 1995;78:1596-611; J Appl Physiol 1993;75:730-7); Broker (USOC Sport Science and Technology Report 1-24, 1994); Candau et al (Med Sci Sports Exerc 1999;31:1441-7)). This comparison was made using the mean squared error of prediction, the systematic error and the random error. RESULTS: The equations of Candau et al, Di Prampero et al, Olds et al (J Appl Physiol 1993;75:730-7) and Whitt gave a moderate mean squared error of prediction (12.7%, 21.6%, 13.2% and 16.5%, respectively) and a low random error (0.5%, 0.6%, 0.7% and 0.8%, respectively). CONCLUSIONS: The equations of Candau et al and Di Prampero et al give the best estimate of mechanical power output when compared with measurements obtained with the SRM training system.
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Umbral Anaerobio/fisiología , Ciclismo/fisiología , Tolerancia al Ejercicio/fisiología , Consumo de Oxígeno/fisiología , Adulto , Antropometría , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Modelos Teóricos , Fenómenos Fisiológicos Musculoesqueléticos , Probabilidad , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: To describe the fat-oxidation rate in triathlon and different modalities of endurance cycling. METHODS: 34 endurance athletes (15 male triathletes, 4 female triathletes, 11 road cyclists and 4 male mountain bikers) underwent a progressive cycloergometer test until exhaustion. Relative work intensity (VO(2max)), minimal lactate concentration (La(-)(min)), lactic threshold, individual lactic threshold (ILT), maximal fat-oxidation rate (Fat(max), Fat(max) zone) and minimal fat-oxidation rate (Fat(min)) were determined in each of the groups and were compared by means of one-way analysis of variance. RESULTS: No significant differences were found for Fat(max), Fat(min) or for the Fat(max) zone expressed as fat oxidation rate (g/min). Intensities -20%, -10% and -5% Fat(max) were significantly lower for mountain bikers with respect to road cyclists and female triathletes, expressed as % VO(2max). Intensities 20%, 10% and 5% Fat(max) were significantly lower for mountain bikers with respect to male triathletes and female triathletes, and for male triathletes in comparison with female triathletes, expressed as % VO(2max). Lactic threshold and La(-)(min) did not show significant differences with respect to Fat(max). Lactic threshold was found at the same VO(2max) with respect to the higher part of the Fat(max) zone, and La(-)(min) at the same VO(2max) with respect to the lower part of the Fat(max) zone. CONCLUSIONS: The VO(2max) of Fat(max) and the Fat(max) zone may explain the different endurance adaptations of the athletes according to their sporting discipline. Lactic threshold and La(-)(min) were found at different relative work intensities with respect to those of Fat(max) even though they belonged to the Fat(max) zone.
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Ciclismo/fisiología , Carbohidratos de la Dieta/metabolismo , Grasas de la Dieta/metabolismo , Metabolismo Energético/fisiología , Carrera/fisiología , Natación/fisiología , Adulto , Índice de Masa Corporal , Calorimetría , Conducta Competitiva/fisiología , Femenino , Humanos , Masculino , Oxidación-Reducción , Consumo de Oxígeno/fisiología , Resistencia Física/fisiologíaRESUMEN
OBJECTIVE: To validate a field test to assess the maximal and submaximal exercise aerobic adaptation under specific conditions, for endurance modality cyclists and triathletes. METHODS: 30 male and 4 female endurance modality cyclists and triathletes, with heterogeneous performance levels, performed three incremental tests: one in the laboratory and two in the field. Assessment of the validity of the field protocol was carried out by the Student's t test, intraclass correlation coefficient (ICC) and coefficient of variation (CV) of the maximal variables (maximal aerobic speed (MAS), maximal aerobic power (MAP), maximal heart rate (HR(max)), maximal blood lactate concentration ([La(-)](max)) and maximal oxygen uptake (VO(2max))) and submaximal variables (heart rate, HR) measured in each one of the tests. The errors in measurement were calculated. The repeatability of the field tests was assessed by means of the test-retest of the two field tests, and the validity by means of the test-retest of the laboratory test with respect to the mean of the two field tests. RESULTS: No significant differences were found between the two field tests for any of the variables studied, but differences did exist for some variables between the laboratory tests with respect to the field tests (MAP, [La(-)](max), humidity (H), barometric pressure (Pb) and some characteristics of the protocols). The ICC of all the variables was high and the CV for the MAP was small. Furthermore, the measurement errors were small and therefore, assumable. CONCLUSIONS: The incremental protocol of the proposed field test turned out to be valid to assess the maximal and submaximal aerobic adaptation.
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Ciclismo/fisiología , Prueba de Esfuerzo/normas , Consumo de Oxígeno/fisiología , Resistencia Física/fisiología , Adulto , Umbral Anaerobio/fisiología , Femenino , Humanos , Masculino , Oximetría , Valor Predictivo de las Pruebas , Reproducibilidad de los ResultadosRESUMEN
This study investigates the effects of moderate-high altitude on lung function and exercise performance in 46 volunteers (19 females, 27 males), with a mean age of 42.4 +/- 1.4 years (+/- SEM) and varying smoking and exercise habits, who were not previously acclimatized. Measures obtained in the base camp (1140 m) and at altitude (2630 m), in random order, included forced spirometry, maximal voluntary ventilation, maximal inspiratory and expiratory pressures, arterial oxygen saturation and capillary lactate concentration after a standardized exercise test. The smoking history, Fagerström test and degree of habitual physical activity were also recorded for each participant. The percentage of smokers was similar in males (19%) and females (21%) (P = n.s.). Mean habitual physical activity index was 8.2 +/- 0.2 (range, 5.88-11.63). At the base camp, all lung function variables were within the normal range. Lactate concentration after exercise averaged 3.7 +/- 0.3 mm l-1. No significant change was observed at altitude, except for a higher heart rate and a lower arterial oxygen saturation (SaO2) (both at rest and after inspiratory manoeuvres). The smoking history and the degree of physical activity did not influence lung function or exercise performance at altitude. The results of this study show that in middle-aged, healthy, not particularly well-trained individuals, lung function is not significantly altered by moderate-high altitude, despite the absence of any acclimatization period and independent of their smoking history and previous exercise habits.
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Altitud , Pulmón/fisiología , Prueba de Esfuerzo , Femenino , Humanos , Ácido Láctico/sangre , Pulmón/fisiopatología , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Pruebas de Función Respiratoria , Fumar/fisiopatologíaRESUMEN
In some trained athletes, maximal exercise ventilation is believed to be constrained by expiratory flow limitation (FL). Using the negative expiratory pressure method, we assessed whether FL was reached during a progressive maximal exercise test in 10 male competition cyclists. The cyclists reached an average maximal O2 consumption of 72 ml. kg-1. min-1 (range: 67-82 ml. kg-1. min-1) and ventilation of 147 l/min (range: 122-180 l/min) (88% of preexercise maximal voluntary ventilation in 15 s). In nine subjects, FL was absent at all levels of exercise (i.e., expiratory flow increased with negative expiratory pressure over the entire tidal volume range). One subject, the oldest in the group, exhibited FL during peak exercise. The group end-expiratory lung volume (EELV) decreased during light-to-moderate exercise by 13% (range: 5-33%) of forced vital capacity but increased as maximal exercise was approached. EELV at peak exercise and at rest were not significantly different. The end-inspiratory lung volume increased progressively throughout the exercise test. The conclusions reached are as follows: 1) most well-trained young cyclists do not reach FL even during maximal exercise, and, hence, mechanical ventilatory constraint does not limit their aerobic exercise capacity, and 2) in absence of FL, EELV decreases initially but increases during heavy exercise.
Asunto(s)
Ciclismo/fisiología , Ejercicio Físico/fisiología , Ápice del Flujo Espiratorio/fisiología , Adolescente , Adulto , Umbral Anaerobio/fisiología , Prueba de Esfuerzo , Humanos , Mediciones del Volumen Pulmonar , Masculino , Consumo de Oxígeno/fisiología , Pruebas de Función Respiratoria , Ventiladores de Presión NegativaRESUMEN
That asthmatics benefit not only from physical exercise but that they can even reach performance levels comparable to that of non asthmatics is becoming increasingly clear. To reach such a level, asthmatics need to use drugs to prevent effort-related asthma attacks in addition to taking appropriate therapeutic measures. beta 2 agonists are drugs that potentially produce a certain amount of "anabolic" effect, depending on the dose and permanence in tissues, in laboratory and farm animals as well as in humans. We must conclude that the dose needed to obtain this effect is higher than that used for therapeutic purposes in asthma or respiratory diseases. Bearing in mind that oral treatments are considerably less effective than inhaled drugs in exercise-related asthma attacks, that the doses of the latter are lower and that the ergogenic effects of the substances studied are nil or below detection levels, it seems logical to allow individuals with asthma who use such substances to engage in physical exercise. Moreover, the asthmatic whose disease is so severe as to require the use of orally administered beta 2 agonists will in all likelihood be too ill to participate in a sport while that status persists.
Asunto(s)
Agonistas Adrenérgicos beta/uso terapéutico , Asma/tratamiento farmacológico , Ejercicio Físico , Asma/fisiopatología , Humanos , DeportesRESUMEN
The presence of a high prevalence of bronchial hyperresponsiveness and asthma-like symptoms in swimmers has been recently reported. Chlorine, a strong oxidizing agent, is an important toxic gas that the swimmer can breath during swimming. Measurements of the chlorine concentration at the breathing level (< 10 cm) were obtained randomly during five nonconsecutive days in four different swimming pool enclosures. The mean level in all the swimming pools was 0.42 +/- 0.24 mg.m-3, far below the threshold limited value (TLV) of 1.45 mg.m-3 for the work places for a day of work (8 h). The TLV could be reached and even exceeded if we consider the total amount of chlorine that a swimmer inhales in a daily training session of 2 h (4-6 g) compared with a worker during 8 h at the TLV (4-7 g). Low correlation was observed with the number of swimmers in the swimming pool during the measurements (0.446) and other variables as the water surface area of the pool, volume of the enclosure, and the chlorine-addition system in the swimming pool. A low turnover rate in the air with an increase of chlorine levels through the day (P < 0.05) was observed in all pools. The concentration of chlorine in the microenvironment where the swimmer is breathing is below the TLV concentration limit, but nevertheless results in a high total volume of chlorine inhaled by the swimmers in a given practice session. The possible role of chlorine in producing respiratory symptoms in swimmers needs further investigation.
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Cloro , Exposición a Riesgos Ambientales , Natación , Humanos , Concentración Máxima Admisible , Natación/fisiologíaRESUMEN
Three different blood lactate analytic methods were tested for precision, accuracy, linearity, and intermethod comparison: a photoenzymatic assay (PHE), and three electroenzymatic (EE) semiautomatic assays (EE1, EE2, EE3). Reference standards and duplicate capillary blood samples from the earlobe were used. Precision and accuracy of the three techniques, when measuring L-lactate standards, were good in the whole range of measurement (mean variation coefficient, VC = 1.78-3.38%; mean difference = 1.81-3.38%). Correlation between the three methods was high (r = 0.913-0.946), but all three electroenzymatic techniques systematically measured lower values as compared to the PHE tests. The differences ranged from 0.1-1.2 (5 mmol.l-1 PHE level), to 3.4-5.7 (20 mmol.l-1 PHE level). These differences were drastically reduced when a hemolyser and a glycolytic inhibitor were added to the sample prior to the assay. The measurements obtained in capillary blood by the three techniques are not equivalent. The differences are partially attributed to the fact that the PHE technique measures total blood lactate, while the EE methods only measure plasmatic-extraerythrocytic lactate. Some regression equations are presented that may be used to convert values measured by the PHE technique, to EE values and vice versa.