RESUMEN
Being able to psychologically relax after work in the evening is important to the day-to-day recovery process and should enable employees to wake up feeling energized for the next workday. Drawing on affective events theory and allostatic load theory, we expected that employees will be able to psychologically relax when they get home from work if during work (a) they experienced less work-related goal-frustration events and more work-related goal-achievement events and (b) if they were adaptively regulating physiological stress arousal (as indexed by heart rate variability). As such, this research considers that work events, as well as a physiological indicator of parasympathetic regulation, can be important antecedents to off-the-job recovery. Over the course of 5 consecutive workdays, 72 employees completed daily surveys (on waking, at work, and in the evening) and wore an ambulatory electrocardiograph to measure their heart rate variability while at work that afternoon. Multilevel mediation analyses revealed support for our hypotheses at the within-person level, except for the role of goal-attainment events. The finding that goal-frustration events and heart rate variability both contribute to evening relaxation, and then indirectly to next-morning energy, provides initial insights on how both mind and body impact off-the-job recovery. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
Asunto(s)
Logro , Frecuencia Cardíaca/fisiología , Estrés Laboral/fisiopatología , Relajación/fisiología , Relajación/psicología , Trabajo/psicología , Adulto , Emociones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multinivel , Trabajo/fisiología , Adulto JovenRESUMEN
Ensuring a healthier working environment is of utmost importance for companies and global health organizations. In manufacturing plants, the ergonomic assessment of adopted working postures is indispensable to avoid risk factors of work-related musculoskeletal disorders. This process receives high research interest and requires extracting plausible postural information as a preliminary step. This paper presents a semi-automated end-to-end ergonomic assessment system of adopted working postures. The proposed system analyzes the human posture holistically, does not rely on any attached markers, uses low cost depth technologies and leverages the state-of-the-art deep learning techniques. In particular, we train a deep convolutional neural network to analyze the articulated posture and predict body joint angles from a single depth image. The proposed method relies on learning from synthetic training images to allow simulating several physical tasks, different body shapes and rendering parameters and obtaining a highly generalizable model. The corresponding ground truth joint angles have been generated using a novel inverse kinematics modeling stage. We validated the proposed system in real environments and achieved a joint angle mean absolute error (MAE) of 3.19±1.57∘ and a rapid upper limb assessment (RULA) grand score prediction accuracy of 89% with Kappa index of 0.71 which means substantial agreement with reference scores. This work facilities evaluating several ergonomic assessment metrics as it provides direct access to necessary postural information overcoming the need for computationally expensive post-processing operations.
Asunto(s)
Ergonomía/métodos , Enfermedades Musculoesqueléticas/diagnóstico , Enfermedades Profesionales/diagnóstico , Postura/fisiología , Trabajo/fisiología , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Instalaciones Industriales y de Fabricación , Enfermedades Musculoesqueléticas/etiología , Enfermedades Profesionales/etiología , Medición de Riesgo/métodos , Factores de RiesgoRESUMEN
This study compared subjective sleep and subjective health complaints among Norwegian oil rig workers, before and after a two week work period. The study also compared differences between two different work schedules. The workers worked either two weeks of day shift (n=90) or two weeks of a swing shift schedule (n=93), involving one week of night shifts, immediately followed by one week of day shifts. Overall, the workers reported significantly poorer sleep quality and more complaints of insomnia at the end compared to the start of the work period. However, there was no significant difference in terms of subjective health complaints. Furthermore, there were no clear differences in changes in sleep quality, insomnia or subjective health complaints during the work period between day- and swing shift workers. However, at the end of the work period a higher proportion of insomniacs were seen among swing shift workers compared with day workers. To conclude, sleep quality and complaints of insomnia became worse during the work period. However, there were few differences in changes in terms of sleep or subjective health complaints between day- and swing shift, suggesting that 12 h day shift affected sleep and health similarly to the schedule involving night work.
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Industria Procesadora y de Extracción , Enfermedades Profesionales/fisiopatología , Petróleo , Trastornos del Inicio y del Mantenimiento del Sueño/fisiopatología , Sueño/fisiología , Tolerancia al Trabajo Programado/fisiología , Adulto , Femenino , Estado de Salud , Humanos , Masculino , Persona de Mediana Edad , Noruega , Enfermedades Profesionales/etiología , Salud Laboral , Océanos y Mares , Trastornos del Inicio y del Mantenimiento del Sueño/etiología , Encuestas y Cuestionarios , Trabajo/fisiología , Adulto JovenRESUMEN
AIM: To examine reliability and validity of an abbreviated version of Oral Impacts on Daily Performances (OIDP) questionnaire and to analyze the interrelationship among OIDP scores, socio-demographic characteristics and oral health status among 12-15 year old adolescents in Davanagere city, Karnataka, India. METHOD: The descriptive cross-sectional survey was conducted among 900 adolescents aged between 12-15 years. The study subjects were randomly selected from six high schools. Selected subjects completed a survey instrument designed to measure subjective oral health indicators including the eight-item OIDP frequency scores. The study participants were clinically examined for dental caries and completed a self-administered questionnaire about demographic information and oral behaviors. RESULTS: 44% of the students reported at least one oral impact in the last six months. Cronbach's alpha for the OIDP frequency items was 0.81. Eating was the most common performance affected (33%) followed by cleaning teeth (22%) and speaking (20%). The severity of impacts was low for relaxing and carrying out works. CONCLUSION: The OIDP frequency score have acceptable psychometric properties in the context of an oral health survey among 12-15 year old adolescents.
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Actividades Cotidianas , Salud Bucal , Calidad de Vida , Adolescente , Actitud Frente a la Salud , Niño , Estudios Transversales , Índice CPO , Atención Odontológica , Ingestión de Alimentos/fisiología , Femenino , Conductas Relacionadas con la Salud , Estado de Salud , Humanos , India , Masculino , Higiene Bucal , Relajación/fisiología , Autoinforme , Sonrisa/fisiología , Conducta Social , Clase Social , Habla/fisiología , Encuestas y Cuestionarios/normas , Cepillado Dental , Trabajo/fisiologíaRESUMEN
Work related musculoskeletal disorders are seen as an indicating parameter of occupational stress among the women workers engaged in tea leaf plucking operation. The hand plucking (no mechanized plucking is practiced in Assam) being a highly repetitive task requires forceful exertions to reach to the distant periphery of the tea bushes and mechanical compression (pressing against hard surfaces). Specifically it aggravates with awkward positions adopted. The current research addresses to minimize the risk factors associated with CTDs and to ascertain the role of ergonomic design development in improving the situation. Women workforce engaged in tea industry in Assam suffer from back, shoulder, arm and finger pains. Workers perform the activity for 440 minutes in the entire shift with one hour lunch break in between in the garden itself. An ergonomic investigation aiming at studying the strain index of plucking operation in tea industry was conducted. While performing the operation workers were found to assume unnatural posture which is static as well as highly dynamic with a load (tea leaf collecting basket up to weight of 30 kg when filled with plucked leaves) at back. With gradual increment of load and pain though the load is released intermittently the strain level found to remain at a high level. The total QEC scores found for plucking activity was 110 out of 138. To improve the situation and to reduce the work related upper limb disorder (WRULD) an ergonomically designed basket was conceived and trial results showed improvements. The newly designed plucking basket fits the back curvature of the workers well, which keeps the basket in place unlike the existing round basket. The new basket is light in weight having more leaf capacity. Significant reduction in energy expenditure and MSDs suffered was observed while using improved basket over existing basket.
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Agricultura , Trastornos de Traumas Acumulados/prevención & control , Ergonomía , Dolor Musculoesquelético/prevención & control , Enfermedades Profesionales/prevención & control , Hojas de la Planta , Té , Adulto , Metabolismo Energético , Diseño de Equipo , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Esfuerzo Físico , Postura , Trabajo/fisiologíaRESUMEN
Conventional and improved methods of aonla pricking were evaluated ergonomically on an experiment conducted for 20 minute with women workers. The working heart rate, energy expenditure rate, total cardiac cost of work and physiological cost of work with conventional tools varied from 93-102 beats.min-1, 6-7.5 kJ.min-1, 285-470 beats, 14 -23 beats.min-1 while with machine varied from 96-105 beats.min-1, 6.5-8 kJ.min-1 , 336-540 beats, 16-27 beats.min-1 respectively. OWAS score for conventional method was 2 indicating corrective measures in near future while with machine was 1 indicating no corrective measures. Result of Nordic Musculoskeletal Questionnaire revealed that subjects complaint of pain in back, neck, right shoulder and right hand due to unnatural body posture and repetitive movement with hand tool. Moreover pricking was carried out in improper lighting conditions (200-300 lux) resulting into finger injuries from sharp edges of hand tool, whereas with machine no such problems were observed. Output with machine increased thrice than hand pricking in a given time. Machine was found useful in terms of saving time, increased productivity, enhanced safety and comfort as involved improved posture, was easy to handle and operate, thus increasing efficiency of the worker leading to better quality of life.
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Ergonomía , Industria de Procesamiento de Alimentos/instrumentación , Enfermedades Profesionales/etiología , Traumatismos Ocupacionales/etiología , Phyllanthus emblica , Trabajo/fisiología , Adulto , Fenómenos Biomecánicos , Femenino , Traumatismos de los Dedos/etiología , Industria de Procesamiento de Alimentos/métodos , Frutas , Humanos , India , Dolor Musculoesquelético/etiología , Esfuerzo Físico , Preparaciones de Plantas , Postura , Adulto JovenRESUMEN
Changes in autonomic nervous system function have been related to work stress induced increases in cardiovascular morbidity and mortality. Our purpose was to examine whether various heart rate variability (HRV) measures and new HRV-based relaxation measures are related to self-reported chronic work stress and daily emotions. The relaxation measures are based on neural network modelling of individual baseline heart rate and HRV information. Nineteen healthy hospital workers were studied during two work days during the same work period. Daytime, work time and night time heart rate, as well as physical activity were recorded. An effort-reward imbalance (ERI) questionnaire was used to assess chronic work stress. The emotions of stress, irritation and satisfaction were assessed six times during both days. Seventeen subjects had an ERI ratio over 1, indicating imbalance between effort and reward, that is, chronic work stress. Of the daily emotions, satisfaction was the predominant emotion. The daytime relaxation percentage was higher on Day 2 than on Day 1 (4 ± 6% vs. 2 ± 3%, p < 0.05) and the night time relaxation (43 ± 30%) was significantly higher than daytime or work time relaxation on the both Days. Chronic work stress correlated with the vagal activity index of HRV. However, effort at work had many HRV correlates: the higher the work effort the lower daytime HRV and relaxation time. Emotions at work were also correlated with work time (stress and satisfaction) and night time (irritation) HRV. These results indicate that daily emotions at work and chronic work stress, especially effort, is associated with cardiac autonomic function. Neural network modelling of individual heart rate and HRV information may provide additional information in stress research in field conditions.
Asunto(s)
Frecuencia Cardíaca/fisiología , Trabajo/fisiología , Adulto , Factores de Edad , Emociones/fisiología , Femenino , Hospitales , Humanos , Satisfacción en el Trabajo , Masculino , Persona de Mediana Edad , Actividad Motora/fisiología , Relajación/fisiología , Relajación/psicología , Estrés Psicológico/fisiopatología , Estrés Psicológico/psicología , Encuestas y Cuestionarios , Trabajo/psicología , Recursos Humanos , Adulto JovenRESUMEN
BACKGROUND: This study investigates social inequalities in self-rated health dynamics for working-aged adults in four nations, representing distinct welfare regime types. The aims are to describe average national trajectories of self-rated health over a 7-year period, identify social determinants of cross-sectional and longitudinal health and compare cross-national patterns. METHODS: Data are from national household panel surveys in Britain, Germany, Denmark and the USA. The self-rated health of working-age respondents is measured for the years 1995-2001. Social indicators include education, occupational class, employment status, income, age, gender, minority status and marital status. Latent growth curve models are used to estimate both individual change and average national trajectories of self-rated health, conditioned on the social indicators. RESULTS: Ageing-vector graphs reveal general declines in health as people age. They also show differential patterns of change for specific national cohorts. Older cohorts in Denmark had poorer health and young cohorts in the USA had better health in 2001 than 1995. Social covariates predicted baseline health in all four countries, in ways that were consistent with welfare regime theories. Once inequalities in baseline health were accounted for, the few determinants of mean health decline occurred mainly in the USA, again in line with theoretical expectations. Finally, trajectories of health for those in average and advantaged social circumstances were similar, but disadvantaged individuals had much poorer health trajectories than 'average' individuals. The differences were greatest in the countries with lower levels of public transfers. CONCLUSION: National differences in self-rated health trajectories and their social correlates may be attributed partly to welfare policies.
Asunto(s)
Envejecimiento/fisiología , Medicina Basada en la Evidencia , Disparidades en el Estado de Salud , Autoevaluación (Psicología) , Bienestar Social , Adulto , Factores de Edad , Envejecimiento/etnología , Comparación Transcultural , Dinamarca/epidemiología , Femenino , Alemania/epidemiología , Gráficos de Crecimiento , Encuestas Epidemiológicas , Humanos , Estudios Longitudinales , Masculino , Estado Civil/etnología , Estado Civil/estadística & datos numéricos , Persona de Mediana Edad , Programas Nacionales de Salud , Análisis de Regresión , Factores Sexuales , Bienestar Social/etnología , Bienestar Social/estadística & datos numéricos , Reino Unido/epidemiología , Estados Unidos/epidemiología , Trabajo/fisiología , Trabajo/estadística & datos numéricosRESUMEN
OBJECTIVE: The stress hormone cortisol shows a pronounced endogenous diurnal rhythm, which is affected by the sleep/wake cycle, meals and activity. Shift work and especially night work disrupts the sleep/wake cycle and causes a desynchronization of the natural biological rhythms. Therefore, different shift schedules may have different impact on performance at work and health. AIM: The purpose was to study if health, reaction time, and the cortisol rhythm were negatively affected when a group of shift workers changed their work schedule from ordinary day-night shift (fixed shift) to "swing shift". METHODS AND SETTINGS: 19 healthy workers on a Norwegian oil rig participated in the study. They worked 2 weeks offshore followed by 4 weeks off work. The ordinary schedule consisted of 12-h day shift and 12-h night shift every other work period (14 days or nights=fixed shift). "Swing shift" involved 1 week of night shift, followed by 1 week of day shift during the work period. All participants worked ordinary day-night shift when baseline data were collected (questionnaires, saliva cortisol, and reaction time during work). After collection of baseline data the workers changed their work schedule to "swing shift", for every working period, and 9 months later the same data were collected. RESULTS: "Swing shift" did not give any negative health effects or any negative changes in reaction time during the day they shifted from night work to day work. Personnel adapted to night shift within a week regardless of schedule, but recovery from night shift took longer time. During swing shift the cortisol rhythm went back towards a normal rhythm in the second week, but it was not returned completely to normal values when they returned home for the 4 weeks off period. However, the cortisol rhythms were readapted to normal values after 1 week at home. For personnel returning home directly from 14 consecutive night shifts, cortisol adaptation was not complete after 1 week at home. CONCLUSION: We found no increase in health complaints from swing shift or reaction time in the shift from night to day work. Recovery from night shift takes longer time.
Asunto(s)
Ritmo Circadiano/fisiología , Salud , Hidrocortisona/análisis , Pruebas Neuropsicológicas , Tiempo de Reacción/fisiología , Trabajo/fisiología , Adaptación Fisiológica/fisiología , Adulto , Industria Química , Industria Procesadora y de Extracción , Femenino , Humanos , Hidrocortisona/metabolismo , Masculino , Persona de Mediana Edad , Noruega , Océanos y Mares , Petróleo , Trastornos del Sueño del Ritmo Circadiano/metabolismo , Trastornos del Sueño del Ritmo Circadiano/fisiopatología , Trastornos del Sueño del Ritmo Circadiano/psicología , Encuestas y Cuestionarios , Trabajo/psicología , Recursos HumanosRESUMEN
INTRODUCTION: This study investigated the effects of trait anxiety and state worry on working memory performance in a normal sample. Phase one investigated the effects of trait anxiety and state worry on the capacity of specific working memory components. Phase two investigated the validity of Eysenck and Calvo's (1992) Processing Efficiency Theory of worry. METHOD: Sixty adult participants (40 females and 20 males with a mean age of 26 years) were assigned to a 2 (trait anxiety: Low vs. high)x2 (state worry: Low vs. high) between-subjects design. RESULTS: Contrary to prediction, worry did not lead to a decrement in performance on verbal working memory tasks but unexpectedly enhanced performance on visual tasks in participants with low trait anxiety (LTA). The results were also in opposition to expectations for Phase two. Individuals in the conditions of high trait anxiety and/or high state worry (LTA/HW, HTA/LW, and HTA/HW) displayed shorter response latencies than individuals in the LTA and low state worry (LTA/LW) condition on both verbal and spatial working memory (i.e., N-back) tasks. CONCLUSION: Although non-pathological worry is predominantly a verbal-linguistic activity, it may also be complemented by the processing of visual imagery which facilitates problem-solving and adaptive functions.
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Ansiedad/fisiopatología , Ansiedad/psicología , Eficiencia , Evaluación del Rendimiento de Empleados , Memoria/fisiología , Trabajo/fisiología , Trabajo/psicología , Adulto , Femenino , Humanos , Masculino , Inventario de Personalidad , Tiempo de Reacción , Percepción Espacial , Percepción VisualRESUMEN
This study investigated the physiological reactions of companion dogs (Canis familiaris) used in animal-assisted activities and animal-assisted therapy by measuring salivary cortisol concentrations. The dog caregivers (owners) collected saliva samples (a) at 3 control days without therapeutic work, (b) directly before and after each therapeutic session during 3 consecutive months, and (c) again at 3 control days without therapeutic work. The study used an enzyme immunoassay to analyze the samples. Cortisol concentrations were significantly higher during therapy days than on control days. Dogs working during the first half of the day produced higher cortisol concentrations after therapeutic sessions than before, whereas dogs working in the afternoon produced lower cortisol concentrations. Cortisol concentrations were higher in short sessions than in long ones and increased relative to the number of therapeutic sessions done during the sampling period. The results indicate that therapeutic work was physiologically arousing for the dogs in this study. Whether these physiological responses are indicative of potentially negative stress or of positive excitement remains an open question.
Asunto(s)
Perros/fisiología , Hidrocortisona/metabolismo , Saliva/química , Estrés Psicológico/metabolismo , Trabajo/fisiología , Animales , Perros/metabolismo , Femenino , Humanos , MasculinoRESUMEN
BACKGROUND: Low physical activity is known to be a potential risk factor for cardiovascular disease. With high prevalence of cardiovascular diseases in the Portuguese urban population, little is known about how sedentary this population is and what factors are associated to sedentary lifestyles. This study's objective was to examine sedentary lifestyles and their determinants through a cross-sectional study. METHODS: 2134 adults (18 years and older) were interviewed using a standard questionnaire, comprising of social, behavioural and clinical information. Time spent in a variety of activities per day, including: work, household chores, sports, sedentary leisure time and sleep, were self-reported. Energy expenditure was estimated based on the related metabolic equivalent (MET) and time spent in each activity (min/day). Those with less than 10% of energy expenditure at a moderate intensity of 4 METs or higher were categorised as sedentary. The proportion of sedentary people and 95% Confidence Intervals (CI) were calculated, and the magnitude of associations, between sedentary lifestyles and the population characteristics, were computed as age-adjusted odds ratios using logistic regression. RESULTS: Sedentarism in both genders during leisure time is high at 84%, however in full day energy expenditure, which includes physical activity at work, sleeping hours and household chores, 79% of males and 86% of females are found to be sedentary. In leisure-time only, increased age is associated with higher odds of being sedentary in both genders, as well as in women with increased BMI. In comparison, in full-day energy expenditure, sedentarism is more likely to occur in those with higher levels of education and in white-collar workers. CONCLUSIONS: A high prevalence of sedentarism is found in the study participants when measuring leisure-time and full-day energy expenditure. The Portuguese population may therefore benefit from additional promotion of physical activity.
Asunto(s)
Metabolismo Energético/fisiología , Ejercicio Físico/fisiología , Conductas Relacionadas con la Salud , Actividades Recreativas , Estilo de Vida , Actividades Cotidianas , Adolescente , Adulto , Anciano , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Portugal/epidemiología , Relajación , Distribución por Sexo , Sueño/fisiología , Encuestas y Cuestionarios , Población Urbana , Trabajo/fisiologíaRESUMEN
In order to evaluate the effects of dietary taurine supplementation on visual fatigue induced by visual display terminals (VDT) work, 25 male college students aged from 20 to 24 years who were not engaged in VDT work were selected to participate in the study. Volunteers were randomly assigned to either the taurine supplementation (n=13) or the placebo supplementation control group (n=12). Before and after 12 days of taurine (3 g/day) or placebo supplementation, two identical 2.5-hr VDT work tests were performed while recording the P100, N75 and N145 latencies and P100 amplitude of pattern visual evoked potential (PVEP) and the frequency of critical flicker fusion (CFF). Following 2.5-hr of VDT work, the P100 and N75 latencies of PVEP increased ( P<0.01) while the P100 amplitude decreased significantly ( P<0.01). The frequency of CFF also reduced significantly ( P<0.01). After 12 days of taurine supplementation, the reduction in P100 amplitude after VDT work alleviated significantly ( P<0.05). The results suggest that taurine supplementation alleviates visual fatigue induced by VDT work.
Asunto(s)
Astenopía/prevención & control , Estrés Fisiológico/prevención & control , Taurina/administración & dosificación , Adulto , Astenopía/fisiopatología , Astenopía/orina , Terminales de Computador , Potenciales Evocados Visuales/fisiología , Fusión de Flicker/fisiología , Humanos , Masculino , Estrés Fisiológico/fisiopatología , Estrés Fisiológico/orina , Taurina/orina , Trabajo/fisiologíaRESUMEN
This study extends previous research on respite from work and addresses the question of how individuals use their leisure time to recover from work. It is hypothesized that time spent on work-related and household activities has a negative effect on well-being, whereas low-effort, social, and physical activities are assumed to have a positive effect. One hundred Dutch teachers completed a diary on leisure time activities and situational well-being for 5 days, and work situation variables were assessed with a questionnaire. Multilevel analyses in which preleisure well-being and work situation variables were entered as control variables supported 4 of the 5 hypotheses. Moreover, a lagged effect of high time pressure on poor situational well-being was found. The study showed that leisure time activities and a low-stress work situation contribute independently to an individual's well-being.
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Actividades Cotidianas/psicología , Docentes/estadística & datos numéricos , Actividades Recreativas/psicología , Salud Laboral , Trabajo/psicología , Adaptación Psicológica , Salud Holística , Humanos , Países Bajos , Psicometría , Calidad de Vida/psicología , Estrés Psicológico , Encuestas y Cuestionarios , Trabajo/fisiologíaRESUMEN
Changes in blood glutathione antioxidant system in response to exercise and training, and aerobic performance, were investigated. Selenium (Se) supplementation effects on these changes were evaluated. The study was double blind. Both groups selenium (Sel, N = 12) and placebo (Pla, N = 12), followed a 10-wk endurance training program, with a prolonged exhaustive exercise bout performed (Cap Max), before (Pre) and after (Post) training. Blood was sampled before (Bef) and after (Aft) Cap Max. The oxidation of blood glutathione after Cap Max exercise showed a reactive oxygen species production. Training developed maximal aerobic power and capacity, significantly increased (P < 0.001) plasma and erythrocyte glutathione peroxidase (GPx) activity, and decreased (P < 0.001) erythrocyte glutathione reductase activity. The Se supplementation caused an increase in the basal plasma GPx level (P < 0.05). There was also a correlation (r = 0.66, P < 0.05) between the variation in VO2max and that of erythrocyte GPx only in supplemented subjects. Our results confirm that blood glutathione remains a sensitive marker of oxidative stress induced by exhausting submaximal exercise and that the antioxidant potential of GPx can be developed by endurance training. Se supplementation at the dose used had no effect on physical performance.
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Glutatión/sangre , Consumo de Oxígeno/fisiología , Resistencia Física/fisiología , Selenio/farmacología , Adulto , Aerobiosis , Antioxidantes/metabolismo , Método Doble Ciego , Eritrocitos/enzimología , Ejercicio Físico/fisiología , Glutatión Peroxidasa/sangre , Glutatión Reductasa/sangre , Humanos , Masculino , Consumo de Oxígeno/efectos de los fármacos , Educación y Entrenamiento Físico , Placebos , Especies Reactivas de Oxígeno/metabolismo , Selenio/sangre , Trabajo/fisiologíaRESUMEN
Ginseng has been used for several thousand years in the Orient as a tonic, prophylactic agent and 'restorative'. However, its efficacy has been established primarily through clinical experience as opposed to scientific verification of its pharmacological effects. Ginseng has been used by athletes as an ergogenic aid for many years, but there is an absence of compelling research evidence in support of its use for this purpose. Indeed, most of the support favouring the use of ginseng to enhance physical performance is of a testimonial nature. While studies with animals show that ginseng or its active components may prolong survival to physical or chemical stress, there is, generally, a lack of controlled research demonstrating the ability of ginseng to improve or prolong performance in fatigued humans.
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Panax , Plantas Medicinales , Animales , Ensayos Clínicos como Asunto , Medicamentos Herbarios Chinos/efectos adversos , Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/uso terapéutico , Fatiga/fisiopatología , Humanos , Panax/clasificación , Desempeño Psicomotor/fisiología , Estrés Fisiológico/fisiopatología , Trabajo/fisiologíaRESUMEN
The effect of a combination of a warm-up, stretching exercises and massage on subjective scores for delayed onset muscle soreness (DOMS) and objective functional and biochemical measures was studied. Fifty people, randomly divided in a treatment and a control group, performed eccentric exercise with the forearm flexors for 30 min. The treatment group additionally performed a warm-up and underwent a stretching protocol before the eccentric exercise and massage afterwards. Functional and biochemical measures were obtained before, and 1, 24, 48, 72 and 96h after exercise. The median values at the five post-exercise time points differed significantly for DOMS measured when the arm was extended (p = 0.043). Significant main effects for treatment were found on the maximal force (p = 0.026), the flexion angle of the elbow (p = 0.014) and the creatine kinase activity in blood (p = 0.006). No time-by-treatment interactions were found. DOMS on pressure, extension angle and myoglobin concentration in blood did not differ between the groups. This combination of a warm-up, stretching and massage reduces some negative effects of eccentric exercise, but the results are inconsistent, since some parameters were significantly affected by the treatment whereas others were not, despite the expected efficacy of a combination of treatments. The objective measures did not yield more unequivocal results than the subjective DOMS scores.
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Masaje , Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Esfuerzo Físico/fisiología , Adulto , Brazo/fisiología , Creatina Quinasa/sangre , Articulación del Codo/fisiología , Prueba de Esfuerzo , Frecuencia Cardíaca/fisiología , Humanos , Contracción Isotónica/fisiología , Masculino , Relajación Muscular/fisiología , Músculo Esquelético/metabolismo , Mioglobina/sangre , Presión , Factores de Tiempo , Trabajo/fisiologíaRESUMEN
The present study was designed to assess the utility of end-tidal PCO2 (peak concentration of carbon dioxide in a single breath of exhaled air) as an index of psychophysiological activity during performance of a computer-based task and during relaxation. Eleven data-entry operators were monitored continuously for three consecutive, 6 hour work days under the following conditions: (a) during a self-relaxation baseline period; (b) during an abbreviated progressive muscle relaxation period; and (c) during a period of computer-based data-entry work. End-tidal PCO2, respiration frequency, and cardiac inter-beat interval (a measure of heart rate and its variability) were monitored continuously during the three conditions of the study. Self-ratings of relaxation and tension were also monitored at periodic intervals. Consistent with a decrease in psychophysiological arousal, end-tidal PCO2 and self-ratings of relaxation were significantly higher during progressive muscle relaxation than during baseline relaxation. Consistent with an increase in psychophysiological arousal, end-tidal PCO2, cardiac inter-beat interval, and relaxation ratings during data-entry work were significantly lower than during either baseline relaxation or progressive muscle relaxation, while respiration frequency and tension ratings were higher. The findings indicate that end-tidal PCO2 discriminates among different psychophysiological states, and that end-tidal PCO2 may be useful in indexing the stress-health effects of human-computer interactions.