ABSTRACT
The red squat lobster Pleuroncodes monodon is an important fishery resource in the Humboldt Current System (HCS). This decapod is exploited in two fishing units: (a) the northern fishing unit (NFU, from 26°S to 30°S) and (b) the southern fishing unit (SFU, from 32°S to 37°S), each of which have an adjacent nursery area that is the source of recruits to replace the exploited adult populations (in the NFU: off the coast of Coquimbo (28°S) and in the SFU: off the coast of Concepción (36°S)). Marked spatial differences in the environmental conditions of the NFU and SFU, and the biogeographic break that exists between these nursery areas (30°S) may promote changes in the bioenergetic condition of new P. monodon juveniles. To evaluate this, we analyzed the bioenergetic condition (measured as: body mass, lipids, proteins, glucose, and energy) of new juvenile females in the main nursery areas off the Chilean coast. The juvenile females from the SFU showed a higher body mass than those from the NFU. Consistently, the juvenile females from the SFU had a higher content of lipids, proteins, and glucose than those from the NFU, indicative of higher energy contents and a higher lipid/protein ratio in the south compared to the north. Considering the current overexploitation of this fishery resource in the HCS, it is essential to understand how the bioenergetic condition of juvenile females of P. monodon may vary in nursery areas at different latitudes in order to generate sustainable fishery management policies with an ecological approach, designed specifically to each fishing unit. Furthermore, identifying the latitudinal variations of these biochemical compounds in P. monodon juveniles can elucidate the geographic origin of red squat lobsters that present a "better bioenergetic condition" in the HCS, which may significantly benefit sustainable fishing certification processes.
Subject(s)
Anomura , Ecosystem , Animals , Female , Antarctic Regions , Energy Metabolism , Glucose , LipidsABSTRACT
BACKGROUND: Kinanthropometry offers to exercise and health professionals a standardized procedure of acquiring surface anatomical measurements that might be used to track changes in body composition. AIM: To describe simple anthropometric indices to monitor body composition changes in amateur and elite athletes, and to provide reference values during the competition phase. METHODS: A search of articles indexed in PubMed/MEDLINE, ScienceDirect, Cochrane, and SciELO databases using the string body composition AND (anthropometric OR skinfolds OR circumferences OR girth OR estimation equation) AND "body fat". Inclusion criteria were: quantitative and/or qualitative research published between 2009 and 2020, written in English or Spanish, reporting simple anthropometric indices that included skinfolds, girths, or basic measures in amateur and elite athletes. RESULTS: A total of 51 studies (Price's index = 66.4%) met all the inclusion criteria and were included in this scoping review. Contrary to the frequent practice, the use of a regression equation might not be accurate to evaluate body composition. To avoid this, anthropometrists should base their analysis on the absolute values of the sum of skinfolds (∑S) and related variables, such as skinfold-corrected girths and lean mass index. While not definitive, because further research is required, the practical recommendations and updated reference values in competition phase provided by this review would contribute to the accurate identification of body composition changes. CONCLUSIONS: ∑S and lean mass index have been shown to be valid for monitoring changes in fat mass and fat-free mass, respectively. More research is needed to derive the lean mass index-specific coefficient for each sports population.
Subject(s)
Athletes , Body Composition , Anthropometry/methods , Body Mass Index , Humans , Reference Values , Skinfold ThicknessABSTRACT
Creatine monohydrate (CrM) supplementation has been shown to improve body composition and muscle strength when combined with resistance training (RT); however, no study has evaluated the combination of this nutritional strategy with cluster-set resistance training (CS-RT). The purpose of this pilot study was to evaluate the effects of CrM supplementation during a high-protein diet and a CS-RT program on lower-limb fat-free mass (LL-FFM) and muscular strength. Twenty-three resistance-trained men (>2 years of training experience, 26.6 ± 8.1 years, 176.3 ± 6.8 cm, 75.6 ± 8.9 kg) participated in this study. Subjects were randomly allocated to a CS-RT+CrM (n = 8), a CS-RT (n = 8), or a control group (n = 7). The CS-RT+CrM group followed a CrM supplementation protocol with 0.1 g·kg-1·day-1 over eight weeks. Two sessions per week of lower-limb CS-RT were performed. LL-FFM corrected for fat-free adipose tissue (dual-energy X-ray absorptiometry) and muscle strength (back squat 1 repetition maximum (SQ-1RM) and countermovement jump (CMJ)) were measured pre- and post-intervention. Significant improvements were found in whole-body fat mass, fat percentage, LL-fat mass, LL-FFM, and SQ-1RM in the CS-RT+CrM and CS-RT groups; however, larger effect sizes were obtained in the CS-RT+CrM group regarding whole body FFM (0.64 versus 0.16), lower-limb FFM (0.62 versus 0.18), and SQ-1RM (1.23 versus 0.75) when compared to the CS-RT group. CMJ showed a significant improvement in the CS-RT+CrM group with no significant changes in CS-RT or control groups. No significant differences were found between groups. Eight weeks of CrM supplementation plus a high-protein diet during a CS-RT program has a higher clinical meaningfulness on lower-limb body composition and strength-related variables in trained males than CS-RT alone. Further research might study the potential health and therapeutic effects of this nutrition and exercise strategy.
Subject(s)
Body Composition/drug effects , Creatine/pharmacology , Muscle Strength/drug effects , Performance-Enhancing Substances/pharmacology , Resistance Training/methods , Absorptiometry, Photon , Adipose Tissue/diagnostic imaging , Adult , Diet, High-Protein , Dietary Supplements , Exercise/physiology , Humans , Lower Extremity/physiology , Male , Muscle, Skeletal/drug effects , Pilot Projects , Young AdultABSTRACT
INTRODUÇÃO: A corrente interferencial é uma modalidade bastante utilizada, porém, apresenta como fator limitante a quantidade de acomodações, o que é comum em eletroestimulação. Apesar de possuir alguns recursos que visam reduzir a adaptação fisiológica, não é totalmente eficaz; neste sentido, pode haver diferenças devido à técnica de uso. Assim, o presente estudo pretendeu analisar se há diferenças na adaptação para as formas bipolar ou tetrapolar em indivíduos com dor lombar crônica não específica. MÉTODOS: Ensaio clínico cruzado, composto por 15 voluntárias com dor lombar crônica não específica, as quais receberam terapia bipolar ou tetrapolar em semanas subsequentes. Foi explicado sobre a adaptação à corrente e o que deveria avisar quando ocorresse, e, desta forma, foi computado o número de vezes em que o fenômeno ocorreu, o tempo necessário até ocorrer a primeira adaptação, a intensidade inicial da corrente utilizada e o quanto aumentou-se após a primeira adaptação. RESULTADOS: Para nenhuma das variáveis analisadas, foi observada diferença significativa entre as duas técnicas (p>0,05). CONCLUSÃO: As técnicas analisadas não mostraram diferenças na adaptação em mulheres jovens com dor lombar não específica.
INTRODUCTION: The interferential current is a widely used modality; however, it presents as a limiting factor the amount of accommodation, which is common in electrostimulation. Despite having some resources that aim to reduce physiological adaptation, it is not fully effective in this sense, but there may be differences due to the technique of use. Thus, the present study aimed to analyze whether there are differences in the accommodation for bi- or tetrapolar forms in individuals with chronic nonspecific low back pain. METHODS: Crossover clinical study, consisting of 15 volunteers with chronic nonspecific low back pain, who received bipolar or tetrapolar therapy in subsequent weeks. They were explained about the current accommodation and that they should be told when it occurred, and in this way, the number of times that the phenomenon occurred, the time needed until the first accommodation occurred, the initial intensity of the current used, and how much it increased after the first accommodation were computed. RESULTS: None of the variables analyzed had a significant difference between the two techniques (p>0.05). CONCLUSION: The techniques analyzed showed no differences in accommodation in young women with nonspecific low back pain.
Subject(s)
Humans , Female , Adolescent , Adult , Young Adult , Adaptation, Physiological , Electric Stimulation Therapy/methods , Low Back Pain/therapy , Chronic Disease , Longitudinal StudiesABSTRACT
Asthma is the most common chronic lower respiratory disease in childhood throughout the world; it is characterized by bronchial hyperreactivity and variable airway obstruction. Asthma is a disorder involving autonomic nervous system, immunologic, and psychologic factors in individuals. This work sought to describe the relationship among stress, coping, and disease control in children with asthma between 6 and 12 years of age. This was a cross-sectional correlational quantitative study with the participation of 280 children with asthma admitted to outpatient consultation and to a hospitalization service at a tier IV health institution in the city of Bogotá. An inverse correlation was found between stress and coping (r = -0.581; p < .05); between stress and asthma control (r = -0.545¸ p < .05); and a direct correlation between coping and asthma control (r = 0.759; p < .05). The results show that children with low stress levels have greater control of their disease and assume functional coping against their health status. The theory of Adaptation to Chronic Health Conditions permitted analyzing children's conduct and behaviors against a health situation. These findings provide evidence for promoting interventions directly to patients with asthma, focusing on patients, families, and schools. Thus, it is possible to improve the quality of health care and strengthen primary health care.
ABSTRACT
AIM: Separating infants and their parents after a Caesarean section is still the routine care worldwide. This study investigated three caregiving models on the wakefulness and physiological parameters of full-term infants after an elective Caesarean section. METHODS: Newborn infants born in a Chilean public hospital in 2009-12 were randomised to three groups: cot, fathers' arms or skin-to-skin contact with their father. They were assessed at 15-minute intervals, from 45 to 120 minutes after the Caesarean section. Their physiological parameters were measured, and their wakefulness was assessed using the Neonatal Behavioural Assessment Scale. RESULTS: We studied 95 infant (53% girls) born at a mean gestational age of 38.9 ± 0.9 weeks. Heart rates were significantly higher in the skin-to-skin than cot or fathers' arms groups and showed greater stability over time. Wakefulness was initially higher in the skin-to-skin group, but there were no significant differences by the end of the observation. There were no differences between the groups in peripheral oxygen saturation. Skin-to-skin contact had no negative impact on the infants. CONCLUSION: The skin-to-skin group showed some advantages over the cot and fathers' arms groups when it came to establishing stable physiological parameters and wakefulness. This approach should be supported during mother-infant separation.
Subject(s)
Cesarean Section , Fathers , Chile , Female , Gestational Age , Humans , Infant , Infant, Newborn , Male , Mothers , PregnancyABSTRACT
Post-exercise recovery is a broad term that refers to the restoration of training capacity. After training or competition, there is fatigue accumulation and a reduction in sports performance. In the hours and days following training, the body recovers and performance is expected to return to normal or improve. ScienceDirect, PubMed/MEDLINE, and Google Scholar databases were reviewed to identify studies and position declarations examining the relationship between nutrition and sports recovery. As an evidence-based framework, a 4R's approach to optimizing post-exercise recovery was identified: (i) Rehydration-a fundamental process that will depend on the athlete, environment and sports event; (ii) Refuel-the consumption of carbohydrates is not only important to replenish the glycogen reserves but also to contribute to the energy requirements for the immune system and tissue reparation. Several bioengineered carbohydrates were discussed but further research is needed; (iii) Repair-post-exercise ingestion of high-quality protein and creatine monohydrate benefit the tissue growth and repair; and (iv) Rest-pre-sleep nutrition has a restorative effect that facilitates the recovery of the musculoskeletal, endocrine, immune, and nervous systems. Nutritional consultancy based on the 4R's is important for the wise stewardship of the hydration, feeding, and supplementation strategies to achieve a timely recovery.
Subject(s)
Dietary Carbohydrates/administration & dosage , Exercise/physiology , Myalgia , Sleep Hygiene , Athletic Performance , Family Characteristics , Glycogen , Humans , Nutritional RequirementsABSTRACT
RESUMEN Con el objetivo de describir los cambios funcionales y morfológicos tempranos en el riñón remanente de donantes vivos, se realizó un estudio retrospectivo en el Hospital Cayetano Heredia, en el que se incluyeron 55 individuos. De las historias clínicas, se obtuvieron los datos clínicos y demográficos, así como la depuración de creatinina, la proteinuria, la presión arterial y las dimensiones renales a los 1, 2, 3, 6 y 12 meses después de la donación del riñón. La edad media fue de 40,88 (±9,84) años; el 80% eran mujeres y el índice de masa corporal medio fue de 25,68 (±3,5) kg/m2. Se utilizaron modelos lineales y cuadráticos para estudiar las variables fisiológicas y morfológicas. Durante el tiempo de seguimiento, la tasa de filtración glomerular, la proteinuria, la presión arterial diastólica y la longitud de los riñones mostraron cambios significativos (p < 0,05).
ABSTRACT In order to describe the early functional and morphological changes in the remnant kidney of living donors, a retrospective study was carried out at the Cayetano Heredia Hospital. Data from 55 individuals was included. Clinical and demographic data were obtained from the clinical records, as well as data for creatinine clearance, proteinuria, blood pressure and renal dimensions at 1, 2, 3, 6 and 12 months after kidney donation. The mean age was 40.88 (±9.84) years; 80% were women and the mean body mass index was 25.68 (±3.5) kg/m2. Linear and quadratic models were used to study physiological and morphological variables. During the follow-up time, glomerular filtration rate, proteinuria, diastolic blood pressure, and kidney length showed significant changes (p < 0.05).
Subject(s)
Humans , Male , Female , Kidney Transplantation , Living Donors , Kidney , Physiology , Proteinuria , Tissue Donors , Adaptation, Physiological , Arterial Pressure , Solitary Kidney , Glomerular Filtration RateABSTRACT
PURPOSE: This study evaluated the effect of the use of a powder-type adhesive on masticatory performance and oral health related quality of life (OHRQoL) in patients with normal and resorbed mandibular ridges during adaptation period with complete dentures. METHODS: Forty-two edentulous subjects (12 men, 30 women) were distributed in four groups: normal mandibular ridges with adhesive, n = 10; normal mandibular ridges without adhesive, n = 10; resorbed mandibular ridges with adhesive, n = 11; resorbed mandibular ridges without adhesive, n = 11. Masticatory performance was evaluated by sieving method and OHRQoL by Oral Health Impact Profile in Edentulous Adults (OHIP-EDENT) inventory at 30, 60 and 90 days after the insertion of new complete dentures. Data were analyzed using 2-way ANOVA test and Generalized Estimating Equations (GEEs), α = 0.05. RESULTS: The use of adhesive resulted in better masticatory performance at 30 (35.76 ± 12.63%) and 60 days (30.06 ± 10.54%) after the insertion of the dentures and did not influence on OHRQoL in participants with normal ridges during the adaptation period. The use of adhesive did not interfere on masticatory performance during adaptation period and had a negative effect on masticatory discomfort/disability subscale OHRQoL at 30-day period [5.2(3.6, 6.8)] for resorbed mandibular ridges with new complete dentures. CONCLUSIONS: The use of adhesive can improve masticatory performance of new complete dentures users with normal mandibular ridges in the initial adaptation period up to 60 days after insertion. For resorbed ridges subjects, the use of adhesive had a negative impact on masticatory discomfort/disability OHRQoL at 30 days after insertion.
Subject(s)
Mouth, Edentulous , Quality of Life , Adult , Dental Cements , Denture, Complete , Female , Humans , Male , MasticationABSTRACT
BACKGROUND: There is evidence of hypertensive effects caused by anabolic androgenic steroids (AAS). A single exercise session promotes the acute reduction of blood pressure, but the effects of AAS on this phenomenon are unknown. OBJECTIVES: To investigate the post-exercise blood pressure response in androgenic-anabolic steroid users. METHODS: Thirteen AAS users (23.9±4.3 years old) and sixteen controls (22.1±4.5 years old) performed a session of aerobic exercise. Heart rate and blood pressure were assessed before exercise and during a 60min post-exercise resting period. Repeated ANOVA measures were used to determine differences between the groups. RESULTS: While the control group had a significant reduction in post-exercise systolic blood pressure of up to 13.9±11.6mmHg at 40min, this phenomenon was limited among AAS users who reached a maximum of 6.2±11.5mmHg at 60min. The between groups comparison revealed significant higher post-exercise hypotension (PEH) for the control group at 30min (-12.9±14.1mmHg versus -2.9±7.6mmHg), 40min (-13.9±11.6mmHg versus -2.5±8.3mmHg), 50min (-13.9±13.9mmHg versus -5.0±7.9mmHg) and 60min (-12.5±12.8mmHg versus -6.2±11.5mmHg). There was no significant diastolic PEH in any of the groups. CONCLUSIONS: This study demonstrated impaired systolic post-exercise hypotension as a new adverse effect of AAS usage.
Subject(s)
Anabolic Agents/therapeutic use , Androgens/therapeutic use , Post-Exercise Hypotension/prevention & control , Post-Exercise Hypotension/physiopathology , Testosterone Congeners/therapeutic use , Adult , Anabolic Agents/pharmacology , Androgens/pharmacology , Blood Pressure/drug effects , Case-Control Studies , Heart Rate/drug effects , Heart Rate/physiology , Humans , Systole/drug effects , Systole/physiology , Testosterone Congeners/pharmacology , Young AdultABSTRACT
Resumen Introducción. En Bogotá, hay una prevalencia de sobrepeso y obesidad del 16% y del 6%, respectivamente, tanto en niños como adolescentes escolares 1. En 2013, se implementó el Programa 40X40 (P40X40) en instituciones educativas distritales (IED) con el objetivo de incrementar los niveles de actividad física de los escolares. Objetivo. El presente estudio busca determinar el efecto del P40x40 en la composición corporal de escolares con sobrepeso y obesidad de las IED de Bogotá. Materiales y métodos. Estudio controlado no aleatorizado en el que participaron 1003 escolares (6 a 17 años) asignados a un grupo de intervención (GI) (P40X40) (n=497) y a un grupo control (GC) (n=506). Se evaluó el efecto de dos meses de intervención del P40X40 sobre las variables porcentaje de grasa corporal (PGC), índice de masa corporal (IMC) e índice de masa corporal Zscore (IMCZscore). Resultados. Se presentaron cambios significativos en el GI para todas las variables (p=0.00), con mayor reducción en el PGC para los deportes de tiempo y marca por diferencia de medias (DaMs) (DaMs=1.36). Conclusiones. Al observarse cambios significativos en el GI para todas las variables (p=0.00) sin relevancia clínica, se determinó que el P40X40 requiere modificaciones en cuanto a intensidad, frecuencia y duración si su objetivo es disminuir los niveles de sobrepeso y obesidad en escolares.
Abstract Introduction: In Bogotá, there is a prevalence of overweight and obesity of 16% and 6%, respectively, in both school children and adolescents 1. In 2013, the 40X40 program (P40X40) was implemented by city educational institutions (IED, by its acronym in Spanish) in order to increase levels of physical activity in school children. Objective: This study aims to determine the effect of P40x40 in body composition of overweight and obese school children at public schools in Bogotá. Materials and methods: Non-randomized controlled study involving 1 003 school children (age 6 to 17) assigned to an intervention group (IG) (P40X40) (n=497) and a control group (CG) (n=506). The effect of the P40X40 intervention was assessed at two months in relation to body fat percentage (BFP), body mass index (BMI) and body mass index Zscore (BMIZscore). Results: Significant changes in IG for all variables (p=0.00) were presented, with greater reduction in BFP for time sports and mean difference (DaMs, for its acronym in Spanish) (DaMs = 1.36). Conclusions: After observing significant changes in the IG for all variables (p=0.00) with no clinical relevance, it was determined that the P40X40 requires changes in intensity, frequency and duration if the goal is to reduce levels of overweight and obesity in school children.
ABSTRACT
Climate is a major selective force in nature. Exploring patterns of inter- and intraspecific genetic variation in functional traits may explain how species have evolved and may continue evolving under future climate change. Photoprotective pigments play an important role in short-term responses to climate stress in plants but knowledge of their long-term role in adaptive processes is lacking. In this study, our goal was to determine how photoprotective mechanisms, morphological traits and their plasticity have evolved in live oaks (Quercus series Virentes) in response to different climatic conditions. For this purpose, seedlings originating from 11 populations from four live oak species (Quercus virginiana, Q. geminata, Q. fusiformis and Q. oleoides) were grown under contrasting common environmental conditions of temperature (tropical vs temperate) and water availability (droughted vs well-watered). Xanthophyll cycle pigments, anthocyanin accumulation, chlorophyll fluorescence parameters and leaf anatomical traits were measured. Seedlings originating from more mesic source populations of Q. oleoides and Q. fusiformis increased the xanthophyll de-epoxidation state under water-limiting conditions and showed higher phenotypic plasticity for this trait, suggesting adaptation to local climate. Likewise, seedlings originating from warmer climates had higher anthocyanin concentration in leaves under cold winter conditions but not higher de-epoxidation state. Overall, our findings suggest that (i) climate has been a key factor in shaping species and population differences in stress tolerance for live oaks, (ii) anthocyanins are used under cold stress in species with limited freezing tolerance and (iii) xanthophyll cycle pigments are used when photoprotection under drought conditions is needed.
Subject(s)
Cold Temperature , Droughts , Pigments, Biological/metabolism , Plant Leaves/physiology , Quercus/physiology , Adaptation, Physiological , Anthocyanins/metabolism , Central America , Chlorophyll/metabolism , Climate Change , Genetic Variation , North America , Plant Leaves/anatomy & histology , Quercus/anatomy & histology , Quercus/genetics , Species Specificity , Xanthophylls/metabolismABSTRACT
An increase in altitude leads to a proportional fall in the barometric pressure, and a decrease in atmospheric oxygen pressure, producing hypobaric hypoxia that affects, in different degrees, all body organs, systems and functions. The chronically reduced partial pressure of oxygen causes that individuals adapt and adjust to physiological stress. These adaptations are modulated by many factors, including the degree of hypoxia related to altitude, time of exposure, exercise intensity and individual conditions. It has been established that exposure to high altitude is an environmental stressor that elicits a response that contributes to many adjustments and adaptations that influence exercise capacity and endurance performance. These adaptations include increase in hemoglobin concentration, ventilation, capillary density and tissue myoglobin concentration. However, a negative effect in strength and power is related to a decrease in muscle fiber size and body mass due to the decrease in the training intensity. Many researches aim at establishing how training or living at high altitudes affects performance in athletes. Training methods, such as living in high altitudes-training low, and training high-living in low altitudes have been used to research the changes in the physical condition in athletes and how the physiological adaptations to hypoxia can enhance performance at sea level. This review analyzes the literature related to altitude training focused on how physiological adaptations to hypoxic environments influence performance, and which protocols are most frequently used to train in high altitudes.
A mayor altitud se produce una disminución proporcional en la presión barométrica y atmosférica del oxígeno. Esto genera hipoxia hipobárica que afecta, en diferentes grados, a todos los órganos, sistemas y funciones del organismo. La reducción crónica de la presión parcial de oxígeno hace que los individuos se adapten y se ajusten a este estrés fisiológico. La intensidad de estas adaptaciones depende de factores como el grado de hipoxia relacionado con la altitud, el tiempo de exposición, la intensidad del ejercicio y las condiciones individuales. Se ha establecido que la exposición a la altura produce una respuesta fisiológica que contribuye en muchos de los ajustes y adaptaciones que influyen la capacidad de ejercicio y de resistencia aeróbica. Estas adaptaciones incluyen aumento en la ventilación, densidad capilar y concentración de mioglobina tisular y hemoglobina. Sin embargo, hay un efecto negativo en fuerza y potencia relacionado con una disminución en la masa muscular y el tamaño de la fibra, por una menor intensidad del entrenamiento. Métodos de entrenamiento como vivir alto -entrenar bajo y entrenar alto-vivir bajo han sido desarrollados e investigados para establecer los cambios en la condición física de los atletas y cómo las adaptaciones fisiológicas a la hipoxia pueden mejorar su desempeño a nivel del mar. Esta revisión analiza la literatura relacionada con el entrenamiento en altura, centrándose en la influencia las adaptaciones fisiológicas a ambientes hipóxicos en el rendimiento y desempeño de los atletas; y cuáles son los protocolos más frecuentemente utilizados para entrenar en altura.
A maior altitude se produz uma diminuição proporcional na pressão barométrica e atmosférica do oxigeno. Isto gera hipoxia hipobárica que afeita, em diferentes graus, a todos os órgãos, sistemas e funções do organismo. A redução crônica da pressão parcial de oxigeno faz que os indivíduos se adaptem e se ajustem a este estresse fisiológico. A intensidade destas adaptações depende de fatores como o grau de hipoxia relacionado com a altitude, o tempo de exposição, a intensidade do exercício e as condições individuais. Tem se estabelecido que a exposição à altura produz uma resposta fisiológica que contribui em muitos dos ajustes e adaptações que influem a capacidade de exercício e se resistência aeróbica. Estas adaptações incluem aumento na ventilação, densidade capilar e concentração de mioglobina tissular e hemoglobina. No entanto, existe um efeito negativo em força e potencia relacionado com uma diminuição na massa muscular e o tamanho da fibra, por uma menor intensidade do treinamento. Métodos de treinamento como viver no alto e treinar baixo têm sido desenvolvidos e pesquisados para estabelecer as mudanças na condição física dos atletas e como as adaptações fisiológicas à hipoxia podem melhorar seu desempenho à altura do mar. Esta revisão analisa a literatura relacionada com o treinamento em altura, se centrando em como as adaptações fisiológicas a ambientes hipõxicos influem no rendimento e desempenho dos atletas; e quais são os protocolos mais frequentemente utilizados para treinar em altura.
Subject(s)
Humans , Adaptation, Physiological , Exercise , Athletic Performance , Altitude , HypoxiaABSTRACT
O objetivo do estudo foi analisar o efeito de programa de treinamento aeróbio sobre parâmetros cardiovasculares, metabólicos e de composição corporal comparando diferentes periodizações. Sessenta e cinco bombeiros militares/ES (25,9 ± 0,6 anos) foram divididos em quatro grupos: controle (Gcon, n = 15) sem tratamento; ondulatório (Gond, n = 18), escalonado (Ges, n = 17), e crescente (Gcres, n = 15), e treinaram 13 semanas, três sessões semanais de 30 minutos e intensidades de 60% a 90% FCmáx. A frequência cardíaca (FC) foi controlada em todas as sessões . Antes e após o programa foram realizadas avaliações antropométricas e teste cardiopulmonar (Aerosport TEEM-100). Houve redução no percentual de gordura, bradicardia em repouso e da FC submáxima com aumento do consumo de oxigênio, e redução do duplo produto, da PAD em repouso para os três grupos treinados, sem vantagens adicionais para o Gcres. Esses resultados sugerem que programas de treinamento aeróbio com distribuição de intensidade ao longo das semanas de forma escalonada e/ou ondulatória podem ser mais apropriados para indivíduos não atletas...
The aim of the present study was to analyze the effect of different periodization models of aerobic training on cardiovascular and metabolic parameters, and body composition. Sixty-five military firefighters y / ES (25.9 ± 0.6 years) were divide into four groups: control (GCON, n = 15) without treatment; undulating (Gu, n = 18), scaled (Gs, n = 17) and increasing (Gi, n = 15); they trained during 13 weeks, three weekly sessions of 30 minutes at intensities of 60% to 90% HRmax. Heart rate (HR) was monitored in all sessions . Anthropometric measurements and cardiopulmonary exercise testing (Aerosport TEEM-100) were conducted before and after the experimental program. A reduction in body fat percentage, bradycardia at rest and submaximal HR with increased oxygen consumption, and reduction of RPP, in DBP at rest for all three groups trained without advantages for Gi, were observed. These results suggest that training programs which includes increasing and/or undulating aerobic training models may be more suitable for non-athletes...
Subject(s)
Humans , Male , Adult , Cardiovascular System , Exercise , Heart RateABSTRACT
INTRODUÇÃO: O potencial de ação (PA) origina-se graças a uma perturbação do estado de repouso da membrana celular, com consequente fluxo de íons, por meio da membrana e alteração da concentração iônica nos meios intra e extracelular. OBJETIVOS: Sintetizar o conhecimento científico acumulado até o presente sobre o potencial de ação neural e o seu processo de adaptação sob aplicação de um estímulo constante. MATERIAIS E MÉTODOS: Busca realizada nas bases Springer, ScienceDirect, PubMed, IEEE Xplore, Google Acadêmico, Portal de Periódicos da Capes, além de livros referentes ao assunto. O idioma de preferência selecionado foi o inglês, com as keywords: action potential; adaptation; accommodation; rheobase; chronaxy; nerve impulse. Efetuou-se a procura de artigos com uma janela de tempo de 1931 a 2010 e livros de 1791 a 2007. RESULTADOS: Dos trabalhos selecionados, foram extraídas informações a respeito dos seguintes tópicos: potencial de ação e suas fases; condução nervosa; reobase; cronaxia; acomodação; e adaptação neuronal. CONCLUSÃO: Um estímulo que crie PA, se aplicado de maneira constante, pode reduzir a frequência de despolarizações em função do tempo e, consequentemente, adaptar a célula. O tempo que a célula demora, na ausência de estímulos, para recuperar sua frequência original é definido como desadaptação.
INTRODUCTION: The action potential (AP) arises due to a disturbance of the resting state of the cell membrane with consequent flow of ions across the membrane and ion concentration changes in intra and extra cellular space. OBJECTIVES: This article aims to summarize the scientific knowledge accumulated to date on the action potential and neural adaptation in the process of applying a constant stimulus. MATERIALS AND METHODS: This is a literature review on the bases Springer, ScienceDirect, PubMed, IEEE Xplore, Google Scholar, Capes Periodicals Portal as well as books on the topic. The selected preferred language was English with the keywords: action potential; adaptation, accommodation; rheobase; chronaxy; nerve impulse. We conducted a search of articles with a wide time window from 1931 to 2010 and books from 1791 to 2007. RESULTS: In the selected studies was extracted information about the following topics: action potential and its stages; nerve conduction; rheobase; chronaxie, accommodation, and adaptation. CONCLUSION: A stimulus that creates AP, if applied consistently, can reduce the frequency of depolarization as a function of time and, consequently, to adapt the cell. The time it takes the cell in the absence of stimuli, to recover its original frequency, is defined as a disadaptation.
Subject(s)
Action Potentials , Adaptation, Physiological , Chronaxy , Ion Channels , Nerve TissueABSTRACT
Los diferentes tipos de mecanismos que emplea el organismo cuando se enfrenta a una situación de hipoxia incluyen la acomodación, la aclimatación y la adaptación. La acomodación es la respuesta inicial a la exposición aguda a la hipoxia de altura y se caracteriza por aumento de la ventilación y de la frecuencia cardiaca. La aclimatación se presenta en los individuos que están temporalmente expuestos a la altura y, que en cierto grado, les permite tolerar la altura. En esta fase hay un incremento en la eritropoyesis, se incrementa la concentración de hemoglobina y mejora la capacidad de transporte de oxígeno. La adaptación es el proceso de aclimatación natural donde entra en juego las variaciones genéticas y la aclimatación que les permiten a los individuos vivir sin dificultad en la altura. La testosterona es una hormona que regula la eritropoyesis y la ventilación, podría estar asociada con los procesos de aclimatación y adaptación a la altura. La eritrocitosis excesiva que conduce al mal de montaña crónico es causada por una baja saturación arterial de oxígeno, una ineficiencia ventilatoria y reducida respuesta ventilatoria a la hipoxia. La testosterona se incrementa en la exposición aguda en la altura y en los nativos de altura con eritrocitosis excesiva. Los resultados de las investigaciones actuales permitirían concluir que el incremento de la testosterona y de la hemoglobina son buenas para la aclimatación adquirida pues mejoran el transporte de oxígeno pero no para la adaptación a la altura, dado que valores altos de testosterona en suero se asocian con eritrocitosis excesiva.
The different types of response mechanisms that the organism uses when exposed to hypoxia include accommodation, acclimatization and adaptation. Accommodation is the initial response to acute exposure to high altitude hypoxia and is characterized by an increase in ventilation and heart rate. Acclimatization is observed in individuals temporarily exposed to high altitude, and to some extent, it enables them to tolerate the high altitudes. In this phase, erythropoiesis is increased, resulting in higher hemoglobin and hematocrit levels to improve oxygen delivery capacity. Adaptation is the process of natural acclimatization where genetical variations and acclimatization play a role in allowing subjects to live without any difficulties at high altitudes. Testosterone is a hormone that regulates erythropoiesis and ventilation and could be associated to the processes of acclimatization and adaptation to high altitude. Excessive erythrocytosis, which leads to chronic mountain sickness, is caused by low arterial oxygen saturation, ventilatory inefficiency and reduced ventilatory response to hypoxia. Testosterone increases during acute exposure to high altitude and also in natives at high altitude with excessive erythrocytosis. Results of current research allow us to conclude that increase in serum testosterone and hemoglobin is adequate for acclimatization, as they improve oxygen transport, but not for high altitude adaptation, since high serum testosterone levels are associated to excessive erythrocytosis.
Subject(s)
Humans , Male , Adaptation, Physiological , Altitude , Hemoglobins/analysis , Testosterone/blood , Acclimatization , Erythropoiesis , PeruABSTRACT
This work investigated the effects of increasing temperature from 30°C to 47°C on the physiological and genetic characteristics of Saccharomyces cerevisiae strain 63M after continuous fermentation with cell recycling in a system of five reactors in series. Steady state was attained at 30°C, and then the temperature of the system was raised so it ranged from 35°C in the last reactor to 43°C in the first reactor or feeding reactor with a 2°C difference between reactors. After 15 days at steady state, the temperature was raised from 37°C to 45°C for 25 days at steady state, then from 39°C to 47°C for 20 days at steady state. Starter strain 63M was a hybrid strain constructed to have a MAT a/α, LYS/lys, URA/ura genotype. This hybrid yeast showed vigorous growth on plates at 40°C, weak growth at 41°C, positive assimilation of melibiose, positive fermentation of galactose, raffinose and sucrose. Of 156 isolates obtained from this system at the end of the fermentation process, only 17.3% showed the same characteristics as starter strain 63M. Alterations in mating type reaction and in utilization of raffinose, melibiose, and sucrose were identified. Only 1.9% of the isolates lost the ability to grow at 40°C. Isolates showing requirements for lysine and uracil were also obtained. In addition, cell survival was observed at 39-47°C, but no isolates showing growth above 41°C were obtained.