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El proceso de envejecimiento está marcado por el sedentarismo y la escasa actividad física, lo que se asocia a la disminución rápida y continua de las capacidades funcionales, la dependencia y la fragilidad. El objetivo del trabajo se orienta a valorar, mediante el test de repeticiones máximas con pesos no extremos, el efecto de la aplicación de ejercicios con pesas para la atención de la sarcopenia. Se aplicaron métodos de los niveles teóricos y empíricos como el analítico, sintético, inductivo, deductivo, revisión documental, análisis documental, observación, encuesta y entrevista. Se aplicó, como instrumento de trabajo, una batería de ejercicios físicos de resistencia a la fuerza, y aeróbicos que permitieron utilizar el método de medición en siete adultos mayores con sarcopenia, atendidos en el Centro de Actividad Física y Salud de la Universidad de las Ciencias de la Cultura Física y Deportes ¨ Manuel Fajardo. Se evaluó el trabajo de fuerza muscular mediante el test mencionado, lo que permitió identificar el peso real de la carga física con la que deben entrenar y, sobre esa base, se elaboró la batería de ejercicios con pesas. En los resultados preliminares registrados, mediante la aplicación del test, se constató que la integración del trabajo con pesas y el aeróbico influyen de manera favorable en la ganancia de fuerza en el adulto mayor.

O processo de envelhecimento é marcado por um estilo de vida sedentário e pouca atividade física, o que está associado ao declínio rápido e contínuo das capacidades funcionais, à dependência e à fragilidade. O objetivo do trabalho visa avaliar, por meio do teste de repetições máximas com pesos não extremos, o efeito da aplicação de exercícios com carga no tratamento da sarcopenia. Foram aplicados métodos dos níveis teórico e empírico como analítico, sintético, indutivo, dedutivo, revisão documental, análise documental, observação, levantamento e entrevista. Como instrumento de trabalho foi aplicada uma bateria de exercícios físicos resistidos de força e aeróbios que permitiu a utilização do método de mensuração em sete idosos com sarcopenia atendidos no Centro de Atividade Física e Saúde da Universidade de Ciências da Cultura Física e. Desporto ¨ Manuel Fajardo. O trabalho de força muscular foi avaliado por meio do referido teste, que possibilitou identificar o real peso da carga física com a qual devem treinar e, com base nisso, foi desenvolvida a bateria de exercícios com pesos. Nos resultados preliminares registrados, por meio da aplicação do teste, foi confirmado que a integração do trabalho com pesos e do trabalho aeróbio influencia favoravelmente o ganho de força em idosos.

The aging process is marked by a sedentary lifestyle and little physical activity, which is associated with the rapid and continuous decline in functional capacities, dependency and fragility. The objective of the work is aimed at assessing, through the test of maximum repetitions with non-extreme weights, the effect of the application of exercises with weights for the care of sarcopenia. Methods from the theoretical and empirical levels such as synthetic analytical, inductive-deductive, documentary review, documentary analysis, observation, survey and interview were applied. As a working instrument, a set of strength endurance and aerobic physical exercises was applied that allowed the measurement method to be used in seven older adults with sarcopenia, treated at the Center for Physical Activity and Health of the University of Sciences. of Physical Culture and Sports ¨Manuel Fajardo¨. The muscular strength work was evaluated using the aforementioned test, which made it possible to identify the real weight of the physical load with which they must train and, on that basis, the set of exercises with weights was developed. In the preliminary results recorded, through the application of the test, it was confirmed that the integration of weight work and aerobic work favorably influences strength gain in the older adults.

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Behavioral momentum theory (BMT) provides a theoretical and methodological framework for understanding how differentially maintained operant responding resists disruption. A common way to test operant resistance involves contingencies with suppressive effects, such as extinction or prefeeding. Other contingencies with known suppressive effects, such as response-cost procedures arranged as point-loss or increases in response force, remain untested as disruptive events within the BMT framework. In the present set of three experiments, responding of humans was maintained by point accumulation programmed according to a multiple variable-interval (VI) VI schedule with different reinforcement rates in either of two components. Subsequently, subtracting a point following each response (Experiment 1) or increasing the force required for the response to be registered (Experiments 2 and 3 decreased response rates, but responding was less disrupted in the component associated with the higher reinforcement rate. The point-loss contingency and increased response force similarly affected response rates by suppressing responding and human persistence, replicating previous findings with humans and nonhuman animals when other types of disruptive events (e.g., extinction and prefeeding) were investigated. The present findings moreover extend the generality of the effects of reinforcement rate on persistence, and thus BMT, extending the analysis of resistance to two well-known manipulations used to reduce responding in the experimental analysis of behavior.

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The effects of voluntary running on the skeletal muscle of rats with pulmonary arterial hypertension (PAH) were tested in the present study. PAH was induced in rats by a single injection of monocrotaline (MCT, 60 mg/kg). Rats in the sedentary hypertension (HS) group had their tolerance to physical exertion reduced throughout the experiment, while those in the sedentary control (SC), exercise control (EC), exercise hypertension (EH) and median exercise (EM) groups maintained or increased. Despite that, the muscular citrate synthase activity was not different between groups. The survival time was higher in the EH (32 days) than in the SH (28 days) (p = 0.0032). SH and EH groups showed a lower percentage of muscle fiber and a higher percentage of extracellular matrix compared to control groups (p < 0.0001). However, the EM and EH groups presented higher percentage of muscle fiber and lower percentage of extracellular matrix than SH group (p < 0.0001). Regarding muscular gene expression, the SH and EM groups showed a lower expression of PGC1-α (p = 0.0024) and a higher expression of VEGF (p = 0.0033) compared to SC, while PGC1-α was elevated in the EH. No difference between groups was found for the carbonylated protein levels (p > 0.05), while the TNF-α/IL-10 ratio was augmented in the EH (p = 0.0277). In conclusion, voluntary running augments the proportion of fiber and affects the gene expression of inflammatory and mitochondrial biogenesis' markers in the skeletal muscle of rats with MCT-induced PAH, which benefits their survival and tolerance to physical effort.

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We compared the effects of resistance training (ResisT) to pyramidal and traditional weightlifting sets on men's psychophysiological responses. In a randomized crossover design, 24 resistance-trained males performed drop-set, descending pyramid, and traditional ResisT in the barbell back squat, 45° leg press, and seated knee extension. We assessed participants' rating of perceived exertion (RPE) and feelings of pleasure/displeasure (FPD) at the end of each set and at 10, 15, 20, and 30 minutes post-session. No differences were detected across ResisT Methods in total training volume (p = 0.180). Post hoc comparisons revealed that drop-set training elicited higher RPE (M 8.8 SD 0.7 arbitrary units) and lower FPD (M -1.4 SD 1.5 arbitrary units) values compared to descending pyramid (M Set RPE 8.0 SD 0.9 arbitrary units and M Set FPD 0.4 SD 1.6 arbitrary units) and traditional set (M Set RPE 7.5 SD 1.1 arbitrary units and M Set FPD 1.3 SD 1.2 arbitrary units) schemes (p < 0.05). In addition, drop-set training elicited higher session RPE (M 8.1 SD 0.8 arbitrary units) and lower session FPD (M 0.2 SD 1.4 arbitrary units) values than descending pyramid and traditional ResisT (p < 0.001). Similarly, descending pyramid training elicited higher session RPE (M 6.6 SD 0.9 arbitrary units) and lower session FPD (M 1.2 SD 1.4 arbitrary units) than traditional set (M Session RPE 5.9 SD 0.8 arbitrary units and M Session FPD 1.5 SD 1.2 arbitrary units) training (p = 0.015). No differences were found in the temporality of post-session metrics, suggesting that testing 10 and 15 minutes post-ResisT was sufficient to assess session RPE (p = 0.480) and session FPD (p = 0.855), respectively. In conclusion, even with similar total training volume, drop-set training elicited more pronounced psychophysiological responses than either pyramidal or traditional ResisT in resistance-trained males.

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BACKGROUND: Sickle cell disease is the most common genetic hemoglobinopathy globally and systemically affects body functioning, decreasing exercise capacity. OBJECTIVE: To assess exercise capacity through the 6-minute walk test (6MWT) and biomarkers in children and adolescents with sickle cell disease. MATERIALS AND METHODS: Cross-sectional study involving 20 children and adolescents from Brazil. Demographic and socioeconomic data were obtained. Baseline measurements included biomarkers (red blood cells, hemoglobin, hematocrit, white blood cells, platelets, reticulocytes, lactate dehydrogenase, creatine phosphokinase, C-reactive protein, interleukin 6, and fetal hemoglobin). The following data were obtained before, during, and after the 6MWT: heart rate, blood pressure, and peripheral oxygen saturation. RESULTS: Eighteen children and adolescents ages 5-14 years old were analyzed, 61.1% boys, 100% black or brown, and 61.1% in primary education, with low household income. The average distance walked in 6MWT was 463.8 (137.7) m, significantly less than the predicted value (P < .001). The distance of 6MWT was associated positively with age (P = .042) and inversely with reticulocyte count (P = .42) and interleukin 6 (P = .00). Age modified the effect of interleukin 6 in younger children (P = .038). CONCLUSION: Our findings suggest increased baseline levels of biomarkers of hemolysis and inflammation impact on 6MWT performance.

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Asthma involves an increase in airway resistance even in periods between attacks, which generates changes in thoracoabdominal kinematics. The aim of the present study was to detect these adaptations at rest and after physical effort. Evaluations were performed using optoelectronic plethysmography at rest and immediately after physical effort of moderate intensity. Thirty-two children and adolescents participated in the present study (16 asthma- AG and 16 health controls-CG). After exercise, the AG exhibited a less variability of respiratory variables. The kinematic behavior of thoracoabdominal motion was the inverse of that found in healthy controls. These findings suggest mechanical and physiological adaptations to minimize the possible turbulence of the airflow and reduce the impact of airway resistance during physical exertion. Moreover, these changes are found even at rest and in patients whose asthma is clinically controlled.

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Background: There are still no studies of the cardiovascular safety of the isolated use of Citrus aurantium in aerobic submaximal exercise. Objective: To evaluate the effect of C. aurantium supplementation on the recovery of cardiorespiratory and autonomic parameters following a session of submaximal aerobic exercise. Methods: Twelve healthy male adults achieved a crossover, randomized, double-blind, and placebo-controlled trial. C. aurantium (600 mg, p-synephrine at 30% amount [180 mg]) or placebo (600 mg of starch) were ingested 90 min before evaluation in randomized days. We evaluated systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), mean arterial pressure (MAP), heart rate (HR) and, HR variability indexes at Rest and during 60 min of recovery from exercise. Results: Citrus aurantium ingestion accelerated the reduction in SBP after exercise, anticipated the return of vagal modulation of the heart after exercise via the HF (ms2), pNN50 (%), and 2 UV% indices. Moreover, rushed the output of sympathetic modulation after exercise via the 0V% index. No unfavorable cardiovascular effects were achieved for HR, DBP, PP, and MAP parameters. Conclusions: Citrus aurantium was shown to be safe for the cardiovascular and autonomic systems alongside submaximal aerobic exercise in healthy males.

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ABSTRACT The fundamental objective of military field training exercises (FTX) is to prepare military personnel for real-life operations through simulated scenarios. These training sessions often require extreme physical efforts with prolonged, high-intensity exercises that can be combined with food restrictions and partial, or total, sleep deprivation. Such conditions can compromise an individual's physical performance and cause tissue damage, thus affecting their health. This study aimed to perform a systematic review of the literature to identify studies that measured the changes in hormone levels and biomarkers of cellular injury and oxidative stress resulting from FTX with high levels of energy expenditure combined with food and sleep restrictions. PubMed and the Scopus database were searched for articles that combined physical effort/food restriction/sleep deprivation with military training. The initial database search identified 158 articles that were reduced to 18 after confirmation. Significant reductions were reported in thyroid hormones, T3, T4, and anabolic hormones such as testosterone, insulin and androstenedione. An exception for GH was found, which increased throughout FTX. Less distinct responses to FTX were observed with cortisol, TSH and LH. The presence of biomarkers for cellular damage (myoglobin, TNF, and CRP) and increased immune response activities were also described. The scarcity of information on oxidative stress, analyses of cellular injury and biomarkers of inflammatory responses warrants the future study of these topics, which could be helpful in facilitating the safe and effective physical preparations of the members of the armed forces.

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The fundamental objective of military field training exercises (FTX) is to prepare military personnel for real-life operations through simulated scenarios. These training sessions often require extreme physical efforts with prolonged, high-intensity exercises that can be combined with food restrictions and partial, or total, sleep deprivation. Such conditions can compromise an individual's physical performance and cause tissue damage, thus affecting their health. This study aimed to perform a systematic review of the literature to identify studies that measured the changes in hormone levels and biomarkers of cellular injury and oxidative stress resulting from FTX with high levels of energy expenditure combined with food and sleep restrictions. PubMed and the Scopus database were searched for articles that combined physical effort/food restriction/sleep deprivation with military training. The initial database search identified 158 articles that were reduced to 18 after confirmation. Significant reductions were reported in thyroid hormones, T3, T4, and anabolic hormones such as testosterone, insulin and androstenedione. An exception for GH was found, which increased throughout FTX. Less distinct responses to FTX were observed with cortisol, TSH and LH. The presence of biomarkers for cellular damage (myoglobin, TNF, and CRP) and increased immune response activities were also described. The scarcity of information on oxidative stress, analyses of cellular injury and biomarkers of inflammatory responses warrants the future study of these topics, which could be helpful in facilitating the safe and effective physical preparations of the members of the armed forces.

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Information on fish preference for environmental conditions can be a useful tool to offer them what they want, an important requirement for welfare purposes. Giving that such an approach deals with psychological states of the fish, we investigated whether psychological stress affects fish preference. In this study, we found that the aversive condition of crossing a white open field did not change individual zebrafish's preference for color background or for plant enrichments, despite a great individual variability of preference response. We conclude that individual preferences for environmental conditions are maintained even following a psychological stressor, and highlight that variability in preference options among individuals raises questions about how to best improve welfare of grouped zebrafish.

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Resumo Este estudo de corte transversal investigou a associação entre raça/cor autorrelatada e dois desfechos - demanda psicossocial e demanda física no trabalho - em 1.032 trabalhadores da Limpeza Urbana e da Indústria Calçadista, na Bahia. Mensurou-se demanda psicossocial por meio do Job Content Questionnaire e demanda física, com questões sobre posturas e manuseio de carga. Regressão de Cox forneceu razões de prevalência (RP) ajustadas por idade, sexo e escolaridade. Entre os pretos há maior proporção de coletores de lixo e menor proporção de cargos de supervisão. Trabalhadores pretos estão mais submetidos à alta demanda psicológica e à baixo controle e, consequentemente, à mais alta exigência no trabalho (RP=1,65). Ademais, são mais expostos ao trabalho com braços elevados (RP=1,93) e ao manuseio de carga (RP=1,62), comparados com brancos. Pardos estão mais expostos ao baixo controle (RP=1,36), ao trabalho com braços elevados (RP=1,48) e com manuseio de carga (RP=1,25), também comparados com brancos. Apoio social é mais baixo entre os pretos e pardos. O estudo demonstrou iniquidades nas exposições psicossocial e física no trabalho que estão em acordo com a concepção estrutural do racismo e sua evidência pode contribuir para condutas que ampliem a equidade no mundo do trabalho.

Abstract This cross-sectional study investigated the association between self-reported race/skin color and two outcomes - psychosocial demand and physical demand at work - in 1,032 workers in an urban cleaning services company and two footwear manufacturers, located in the State of Bahia, Brazil. Psychosocial demand was measured through the Job Content Questionnaire and physical demand was measured through questions about postures and cargo handling. A Cox regression analysis provided prevalence ratios (PR) adjusted by age, gender, and educational level. Among blacks, there is a higher proportion of garbage collectors and a lower proportion of supervisory positions. Black workers are more subject to high psychological demand and low job control and, consequently, to high strain (PR=1.65). Also, they are more exposed to work with arms above shoulder level (PR=1.93), and material handling (PR=1.62), compared to white workers. Brown workers are more exposed to low job control (PR=1.36), work with arms above shoulder level (PR=1.48), and material handling (PR=1.25), also compared with whites. Social support is lower among blacks and brown. The study demonstrated inequities in psychosocial and physical exposures at work that are in line with the structural conception of racism. This evidence can contribute to the adoption of practices that increase equity in the world of work.

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The aim of the present study was to investigate lung particulate matter (PM) deposition during endurance exercise and provide a new insight concerning how SARS-CoV-2 could be carried into the respiratory tract. The anatomical and physiological characteristics of the Human Respiratory Tract model were considered for modeling the lung PM deposition during exercise. The Monte Carlo method was performed to randomly generate different values of PM concentrations (1.0, 2.5, and 10.0 µm), minute ventilation, and duration of exercise at moderate, heavy, and severe exercise intensity domains. Compared to moderate and severe intensities, during heavy exercise (75-115 L‧min-1, duration of 10.0-60.0 min) there is greater lung deposition in the bronchiolar region (p < 0.01). In turn, there is greater deposition per minute of exercise at the severe intensity domain (115.0-145.0 L‧min-1, duration of 10.0-20.0 min, p < 0.01). Considering that SARs-CoV-2 could be adsorbed on the particles, exercising under PM exposure, mainly at the severe domain, could be harmful concerning the virus. In conclusion, beyond the traditional minute ventilation assumption, there is a time vs intensity dependence for PM deposition, whereby the severe domain presents greater deposition per minute of exercise. The results observed for PM deposition are alarming since SARs-CoV-2 could be adsorbed by particles and carried into the deeper respiratory tract.

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El tabaquismo es considerado una de las principales causas de morbilidad y mortalidad en la población general. En Chile la prevalencia de tabaquismo alcanza el 36,7% en hombres y 28,5% en mujeres. En este contexto, diversas estrategias farmacológicas y no farmacológicas han sido propuestas para promover la cesación de su consumo, así como para contrarrestar las comorbilidades asociadas al tabaquismo prolongado. Entre ellas, el ejercicio físico ha sido tradicionalmente considerado, por su impacto en la promoción de la cesación del hábito tabáquico, así como también por sus efectos en la reducción de las manifestaciones clínicas del síndrome de abstinencia post cesación. No obstante, estudios realizados en modelos animales durante los últimos 10 años han proporcionado datos contundentes para sustentar la hipótesis de que la práctica regular de ejercicio físico sería también efectiva para prevenir o modular el estrés oxidativo y la respuesta inflamatoria inducida por el tabaco, previniendo el deterioro orgánico de los sistemas fisiológicos expuestos. Esta revisión tiene por objetivo discutir la evidencia publicada respecto a los efectos biológicos inducidos por ejercicio físico y su impacto en la reversión de los mecanismos fisiopatológicos que subyacen a las comorbilidades asociadas al hábito tabáquico, focalizando el análisis en los mecanismos de estrés oxidativo y respuesta inflamatoria del sistema respiratorio y cardiovascular.

Smoking is considered one of the main causes of morbidity and mortality in the general population. In Chile, the prevalence of smoking reaches 36.7% in men and 28.5% in women. In this context, several pharmacological and non-pharmacological strategies have been proposed to promote the cessation of their use, as well as to counteract the comorbidities associated with prolonged smoking. Among them, physical exercise has been traditionally considered, due to its impact on the promotion of cessation of smoking, as well as its effects in reducing the clinical manifestations of withdrawal syndrome. However, studies conducted in animal models during the last 10 years have provided strong data to support the hypothesis that regular practice of physical exercise would also be effective in preventing or modulating oxidative stress and the inflammatory response induced by tobacco, preventing the organic deterioration of exposed physiological systems. The objective of this review is to discuss the published evidence regarding the biological effects induced by physical exercise and its impact on the reversion of the pathophysiological mechanisms underlying the comorbidities associated with smoking, focusing the analysis on the mechanisms of oxidative stress and inflammatory response of the respiratory and cardiovascular system.

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ABSTRACT The objective of the present study was to analyze the influence of execution velocity on rating of perceived exertion (RPE) and on volume of repetitions at different velocities. Methods: The sample consisted of 10 male volunteers (23.4 ± 5.4 years old) with at least 6 months of experience in strength training. The participants performed 8 sets of up to 8 repetitions with an intensity of 60% of 1RM at different velocities of movement execution: slow cadence (6020), moderate cadence (2020) and free cadence. RPE (OMNI-RPE scale) and volume of repetitions performed in each condition were assessed. Results: The number of repetitions executed in the slow- and moderate-cadence protocols was smaller compared to that in the free protocol (p <0.05), as of the 2nd and 6th sets, respectively. RPE in the slow-cadence protocol was higher compared to that in the other cadences (p <0.05). Conclusion: The slow- and moderate-cadence protocols significantly reduce the number of repetitions performed and result in a greater rating of perceived exertion in comparison with free cadence.

RESUMO O objetivo do presente estudo foi analisar a influência da velocidade de execução na percepção subjetiva de esforço (PSE) e o volume de repetições em diferentes velocidades. Métodos: A amostra foi composta por 10 voluntários do sexo masculino (23,4 ± 5,4 anos), com no mínimo 6 meses de experiência no treinamento de força. Os participantes realizaram 8 séries de até 8 repetições com intensidade de 60% de 1RM em diferentes velocidades de execução de movimento: cadência lenta (6020), cadência moderada (2020) e cadência livre. Foram avaliadas a PSE (escala OMNI-RES) e o volume de repetição executadas em cada condição. Resultados: O número de repetições executadas nos protocolos de cadência lenta e moderada foi menor quando comparada ao protocolo livre (p < 0,05) a partir da 2ª e 6ª séries, respectivamente. A PSE no protocolo de cadência lenta foi maior quando comparado com as outras cadências (p<0,05). Conclusão: Os protocolos de cadência lenta e moderada reduzem significativamente o número de repetições realizadas e resultam em maior percepção subjetiva de esforço quando comparado com cadência livre.

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Interoception has been shown to influence self-regulation of effort and perceived exertion during exercise. However, whether interoceptive accuracy influences submaximal and maximal exercise performance, as well as psychophysiological responses to it, remains elusive. We assessed poor (n = 15) and good (n = 17) heartbeat perceivers young men accordingly with their interoceptive accuracy. Heart rate variability (HRV) and blood pressure were measured at rest, and peak power, ratings of perceived exertion (RPE), and HR during a maximal incremental test in a bicycle ergometer. Results: At rest, HR, diastolic and mean blood pressure was lower, and inter-beat intervals were longer for good heartbeat perceivers, with no difference in HRV. During exercise, good and poor heartbeat perceivers exhibited the same submaximal and maximal power, HR, RPE at submaximal intensity, and physical fitness. Interoceptive accuracy does not influence cardiac autonomic modulation perceptual responses and performance at submaximal and maximal intensities during maximal incremental exercise.

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Abstract Objective: To develop a quasi-experimental study to know the changes in physiological responses and perceived efforts of a group of fifteen healthy students that performed a simulated task related with the operation of a CNC lathe in a lab environment. Materials and Methods: The participants were asked to randomly complete a total of eight sessions including single and combined test of physical and mental load. Low/High Physical Load and Low/ High Mental Load were established as independent variables. Heart rate, physical performance, mental performance, and effort perception were established as dependent variables. Conclusions: High load levels have a significant effect on the heart rate increasing, but not in the perception of effort. High levels of mental load have a significant effect on physical and mental performance.

Resumen Objetivo: Desarrollar un estudio quasi-experimental para conocer los cambios en las respuestas fisiológicas y esfuerzos percibidos en un grupo de quince estudiantes sanos que realizaron una tarea simulada relacionada con la operación de un torno CNC en ambiente de laboratorio. Materiales y métodos: Los participantes completaron un total de ocho sesiones que incluyeron pruebas individuales y combinadas de esfuerzo físico y mental. La Carga Mental Baja/Alta y Carga Física Baja/Alta fueron establecidas como variables independientes. Frecuencia cardiaca, desempeño físico, desempeño mental y la percepción de esfuerzo fueron establecidas como variables dependientes. Conclusiones: Los niveles altos de carga física tienen un efecto significativo en el incremento de la frecuencia cardiaca, pero no en la percepción de esfuerzo. Los niveles altos de carga mental tienen un efecto significativo en el desempeño físico y mental.

Resumo Objetivo: Desenvolver um estudo quase-experimental para conhecer as mudanças nas respostas fisiológicas e esforços percebidos em um grupo de 15 estudantes saudáveis que realizaram uma tarefa simulada relacionada com a operação de um torno CNC em ambientes de laboratório. Materiais e métodos: Os participantes completaram um total de 8 sessões que incluíram provas individuais e combinadas de esforço físico e mental. A Carga Mental Baixa/Alta e a Carga Física Baixa/Alta foram estabelecidas como variáveis independentes. Frequência cardíaca, desempenho físico, desempenho mental e a percepção de esforço foram estabelecidas como variáveis dependentes. Conclusões: Os níveis altos de carga física têm um efeito significativo no incremento da frequência cardíaca, mas não na percepção de esforço. Os níveis altos de carga mental têm um efeito significativo no desempenho físico e mental.

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BACKGROUND: Among combat sports, Judo and Brazilian Jiu-Jitsu (BJJ) present elevated physical fitness demands from the high-intensity intermittent efforts. However, information regarding how metabolic and neuromuscular physical fitness is associated with technical-tactical performance in Judo and BJJ fights is not available. This study aimed to relate indicators of physical fitness with combat performance variables in Judo and BJJ. METHODS: The sample consisted of Judo (n = 16) and BJJ (n = 24) male athletes. At the first meeting, the physical tests were applied and, in the second, simulated fights were performed for later notational analysis. RESULTS: The main findings indicate: (i) high reproducibility of the proposed instrument and protocol used for notational analysis in a mobile device; (ii) differences in the technical-tactical and time-motion patterns between modalities; (iii) performance-related variables are different in Judo and BJJ; and (iv) regression models based on metabolic fitness variables may account for up to 53% of the variances in technical-tactical and/or time-motion variables in Judo and up to 31% in BJJ, whereas neuromuscular fitness models can reach values up to 44 and 73% of prediction in Judo and BJJ, respectively. When all components are combined, they can explain up to 90% of high intensity actions in Judo. DISCUSSION: In conclusion, performance prediction models in simulated combat indicate that anaerobic, aerobic and neuromuscular fitness variables contribute to explain time-motion variables associated with high intensity and technical-tactical variables in Judo and BJJ fights.

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OBJETIVO: Describir factor de ponderación de riesgo del factor técnica de manipulación combinada (5 técnicas), analizando sus diferencias en condición dinámico-asimétrica, considerando la carga biomecánica en los segmentos extremidades superiores y columna. MÉTODO: Estudio cuasiexperimental, analítico y transversal, muestra por conveniencia de 100 sujetos (hombres y mujeres) en edad laboral, de la comunidad universitaria de la Universidad de Chile, evaluando cinco técnicas de manipulación de carga, utilizando sistema optoelectrónico, 3D Static Strength Prediction Program, electromiografía de superficie y percepción de esfuerzo. RESULTADOS: En extremidades superiores, se describen diferencias significativas entre técnicas en todas las variables de análisis biomecánico: el patrón de torque, activación muscular y percepción de esfuerzo es mayor en la técnica simétrica sobre hombros y asimétrica que en las otras técnicas. A nivel de columna, la actividad electromiográfica a nivel de erectores espinales entre técnicas es estadísticamente significativa. CONCLUSIÓN: Las técnicas con mayor carga biomecánica son las técnicas "Simétrica sobre Hombro" y "Asimétrica". La técnica "Simétrica a nivel de caderas" genera una carga intermedia, las técnicas "Simétrica a nivel de tronco" y de "Una mano" tienden a ser similares y las menos exigentes.

To describe risk weighting factor of combined manipulation technique factor (5 Technical), analyzing their differences in dynamic-asymmetrical condition, considering the biomechanical load on the upper limbs and spine segments. METHOD: Quasi-experimental, analytical and cross-sectional study, convenience sample of 100 subjects (male and female) in working age, from University of Chile community, assessing five load-handling techniques using optoelectronic system, 3D Static Strength Prediction Program, surface electromyography and perceived exertion. RESULTS: in upper extremities, significant differences in all variables techniques of biomechanical analysis are described: the pattern of torque, muscle activation and perceived exertion is higher in the symmetric on shoulders and asymmetric technique than the other techniques. In a column level, the electromyographic activity in a spinal erector level between techniques is statistically significant. CONCLUSION: The techniques with more biomechanical loading are "Symmetric on Shoulder" and "asymmetric" techniques. The "symmetrical hips level" technique generates an intermediate charge, techniques "trunk level Symmetric" and "One hand" tend to be similar and less demanding.

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OBJECTIVE: This study aims to evaluate the betaine supplementation and its possible ergogenic potential in physically active adults. Data source: In the present review, articles were searched using indexed databases (SciELO and NCBI) and the following keywords were selected for the search: "supplement", "betaine", "performance" and "adults", including terms of lexical proximity, limited to articles in English, published between 2000 and the present date. Inclusion criteria: adults, physically active individuals or individuals under physical test and betaine supplementation. Data synthesis: According to the applied search criteria, 20,750 articles were found, from which only seven obeyed to inclusion parameters after judicious reading of the texts. In these, betaine supplementation was capable to increase anaerobic potency, muscular and isometric endurance, and stimulate an anabolic environment. In contrast, no increase was observed in the plasmatic levels of nitrate/nitrite and, when compared to creatine, betaine supplementation was not able to raise the levels of phosphorylcreatine or strength in sedentary individuals. CONCLUSIONS: The present work showed that betaine supplementation plays an important role as an ergogenic resource, mainly in biomarkers and muscular strength and power; nevertheless, it is apparently ineffective when given to sedentary individuals

OBJETIVO: Este estudo teve como objetivo avaliar a suplementação de betaína e seu possível potencial ergogênico em adultos fisicamente ativos. Fonte de dados: Na presente revisão, artigos foram pesquisados usando bancos de dados indexados (e.g., SciELO e NCBI) e as seguintes palavras-chave foram selecionados para a procura: "suplemento", "betaína", "desempenho" e "adultos", incluindo termos de proximidade léxica, limitado-se a artigos em inglês e português publicados entre 2000 e a presente data. Critérios de inclusão: referirem-se a adultos, indivíduos fisicamente ativos ou sob teste físico e suplementação de betaína. Síntese dos dados: De acordo com os critérios de pesquisa aplicada, 20.750 artigos foram encontrados, dos quais apenas sete obedeceram aos parâmetros de inclusão após leitura criteriosa do texto. Nesses estudos, a suplementação de betaína foi capaz de elevar potência anaeróbica, resistência muscular e isométrica e estimular um ambiente anabólico. Em contraste, não foram encontradas elevações nos níveis plasmáticos de nitrato/nitrito e, quando comparada à suplementação de creatina, não foi capaz de elevar níveis de fosforilcreatina ou força em indivíduos sedentários. CONCLUSÕES: O presente trabalho mostrou que a suplementação de betaína desempenha um papel importante como ergogênico, principalmente em níveis de marcadores biológicos e sobre força e potência muscular, embora aparentemente seja inefetiva quando fornecida a indivíduos sedentários

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