Subcellular fractionation of frozen skeletal muscle samples.

Cell fractionation can be used to determine the localization and trafficking of proteins between cellular compartments such as the cytosol, mitochondria, and nuclei. Subcellular fractionation is usually performed immediately after tissue dissection because freezing may fragment cell membranes and induce organellar cross-contamination. Mitochondria are especially sensitive to freezing/thawing and mechanical homogenization. We proposed a protocol to improve the retention of soluble proteins in the mitochondrial fraction obtained from small amounts of frozen skeletal muscle. Fifty milligrams of the red portion of gastrocnemius muscle from Wistar rats were immediately processed or frozen in liquid nitrogen and stored at -80 °C for further processing. We compared the enrichment of subcellular fractions from frozen/fresh samples obtained with the modified protocol with those obtained by standard fractionation. Western blot analyses of marker proteins for cytosolic (alpha-tubulin), mitochondrial (VDAC1), and nuclear (histone-H3) fractions indicated that all of the procedures resulted in enriched subcellular fractions with minimal organellar cross-contamination. Notably, the activity of the soluble protein citrate synthase was higher in the mitochondrial fractions obtained with the modified protocol from frozen/fresh samples compared with the standard protocol. Therefore, our protocol improved the retention of soluble proteins in the mitochondrial fraction and may be suitable for subcellular fractionation of small amounts of frozen skeletal muscle samples.

Mountain Ultramarathon Induces Early Increases of Muscle Damage, Inflammation, and Risk for Acute Renal Injury.

Purpose: This study aimed to investigate changes in muscle damage during the course of a 217-km mountain ultramarathon (MUM). In an integrative perspective, inflammatory response and renal function were also studied. Methods: Six male ultra-runners were tested four times: pre-race, at 84 km, at 177 km, and immediately after the race. Blood samples were analyzed for serum muscle enzymes, acute-phase protein, cortisol, and renal function biomarkers. Results: Serum creatine kinase (CK), lactate dehydrogenase (LDH), and aspartate aminotransferase (AST) increased significantly throughout the race (P < 0.001, P < 0.001; P = 0.002, respectively), and effect size (ES) denoted a large magnitude of muscle damage. These enzymes increased from pre-race (132 ± 18, 371 ± 66, and 28 ± 3 U/L, respectively) to 84 km (30, 1.8, and 3.9-fold, respectively); further increased from 84 to 177 km (4.6, 2.9, and 6.1-fold, respectively), followed by a stable phase until the finish line. Regarding the inflammatory response, significant differences were found for C-reactive protein (CRP) (P < 0.001) and cortisol (P < 0.001). CRP increased from pre-race (0.9 ± 0.3 mg/L) to 177 km (243-fold), cortisol increased from pre-race (257 ± 30 mmol/L) to the 84 km (2.9-fold), and both remained augmented until the finish line. Significant changes were observed for creatinine (P = 0.03), urea (P = 0.001), and glomerular filtration rate (GFR) (P < 0.001), and ES confirmed a moderate magnitude of changes in renal function biomarkers. Creatinine and urea increased, and GFR decreased from pre-race (1.00 ± 0.03 mg/dL, 33 ± 6 mg/dL, and 89 ± 5 ml/min/1.73 m2, respectively) to 84 km (1.3, 3.5, and 0.7-fold, respectively), followed by a plateau phase until the finish line. Conclusion: This study shows evidence that muscle damage biomarkers presented early peak levels and they were followed by a plateau phase during the last segment of a 217-km MUM. The acute-phase response had a similar change of muscle damage. In addition, our data showed that our volunteers meet the risk criteria for acute kidney injury from 84 km until they finished the race, without demonstrating any clinical symptomatology.

Glycemic Control and Muscle Damage in 3 Athletes With Type 1 Diabetes During a Successful Performance in a Relay Ultramarathon: A Case Report.

Ultramarathon races are fairly demanding and impose substantial physiological stress on healthy athletes. These competitions may thus be considerably more challenging for individuals with diabetes. This case study aims to describe glycemic control, muscle damage, inflammation, and renal function in 3 athletes with type 1 diabetes during a successful performance in a relay ultramarathon. The team completed the race in 29 hours and 28 minutes, earning third place. The total distance covered by each athlete was 68.7, 84.5, and 65.1 km. Most blood glucose levels showed that athletes were in a zone where it was safe to exercise (90-250 mg/dL or 5.0-13.9 mmol/L). Creatine kinase, lactate dehydrogenase, and aspartate aminotransferase serum levels increased 1.2- to 50.7-fold prerace to postrace, and were higher than the reference ranges for all the athletes postrace. Blood leukocytes, neutrophils, and serum C-reactive protein (CRP) increased 1.6- to 52-fold prerace to postrace and were higher than the reference ranges for 2 athletes after the race. Serum creatinine increased 1.2-fold prerace to postrace for all the athletes but did not meet the risk criteria for acute kidney injury. In conclusion, our main findings show evidence of satisfactory glycemic control in athletes with type 1 diabetes during a relay ultramarathon. Moreover, elevation of muscle damage and inflammatory biomarkers occurred without affecting renal function and challenging the maintenance of blood glucose among athletes. These findings are novel and provide an initial understanding of the physiological responses in athletes with type 1 diabetes during ultramarathon races.

Technical and tactical soccer players' performance in conceptual small-sided games / Desempenho técnico e tático de jogadores de futebol em jogos reduzidos conceituais / Rendimiento técnico y táctico de jugadores de fútbol en juegos reducidos conceptuales

Conceptual small-sided games (CSSGs) may be interesting as a methodology for training soccer players given its connection to the unpredictability that is inherent to soccer. Our aim was investigate, through videogrammetry, if the technical and tactical principles promoted through the adoption of distinct rules from two distinct CSSGs (maintaining ball possession; and progression to the target) would actually be achieved. The study included 24 athletes assigned to 6-player teams. Our data showed that the CSSGs' organising principles create situations with differing levels of difficulty that obey the propositions of maintaining ball possession and progression to the target, i.e., CSSGs permit systematic training on technical and tactical components in order to emphasize the concepts adopted in this study in games context. Our data credit the CSSGs for teaching technical and tactical lessons that, when coupled with adequate physical conditioning, can facilitate a player's capacity to merge thoughts and events in different situations.

A utilização de jogos reduzidos conceituais (JRC) pode ser uma metodologia de treino interessante para treinar a imprevisibilidade inerente ao jogo de futebol. Nosso objetivo no presente estudo foi investigar por videogrametria os princípios técnico-táticos adotados em resposta as respectivas regras de dois jogos reduzidos conceituais distintos (manutenção de posse de bola e progressão ao alvo). Participaram do estudo 24 atletas separados em equipes de 6 jogadores. Nossos dados comprovaram que os princípios organizadores dos JRC criam situações distintas com graus de dificuldade diferentes. Ou seja, é possível sistematizar o treinamento dos componentes técnicos e táticos de forma a enfatizar os conceitos adotados neste estudo e inseridos no contexto do jogo. Nossos dados credenciam os JRC para o aprendizado de situações técnico táticas que, aliadas ao condicionamento físico adequado podem contribuir para produzir um jogador treinado para aproximar cada vez mais pensamentos e ações em situações diversificadas.

El uso de los juegos reducidos conceptuales (JRC) puede ser una interesante metodología para entrenar a la imprevisibilidad inherente en el juego de fútbol. Nuestro objetivo en este estudio fue investigar por videogrametría los principios técnico-tácticos adoptadas en respuesta a las respectivas reglas de dos JRC distintos (posesión del balón y la progresión a la meta). El estudio incluyó a 24 atletas divididos en equipos de 6 jugadores. Nuestros datos muestran que los principios de organización de los JRC crean diferentes situaciones con diferentes grados de dificultad. Es decir, es posible sistematizar el desarrollo de los componentes técnicos y tácticos de una manera a enfatizar los conceptos adoptados para este estudio en el contexto del juego. Nuestros datos acreditan JRC para el aprendizaje de situaciones técnicas tácticas que, junto con la preparación física adecuada puede ayudar a producir jugadores capacitados a unir cada vez más pensamientos y acciones en diferentes situaciones.

The geometric curvature of the spine of runners during maximal incremental effort test.

This study sought to analyse the behaviour of the average spinal posture using a novel investigative procedure in a maximal incremental effort test performed on a treadmill. Spine motion was collected via stereo-photogrammetric analysis in thirteen amateur athletes. At each time percentage of the gait cycle, the reconstructed spine points were projected onto the sagittal and frontal planes of the trunk. On each plane, a polynomial was fitted to the data, and the two-dimensional geometric curvature along the longitudinal axis of the trunk was calculated to quantify the geometric shape of the spine. The average posture presented at the gait cycle defined the spine Neutral Curve. This method enabled the lateral deviations, lordosis, and kyphosis of the spine to be quantified noninvasively and in detail. The similarity between each two volunteers was a maximum of 19% on the sagittal plane and 13% on the frontal (p<0.01). The data collected in this study can be considered preliminary evidence that there are subject-specific characteristics in spinal curvatures during running. Changes induced by increases in speed were not sufficient for the Neutral Curve to lose its individual characteristics, instead behaving like a postural signature. The data showed the descriptive capability of a new method to analyse spinal postures during locomotion; however, additional studies, and with larger sample sizes, are necessary for extracting more general information from this novel methodology.

Análise da potência aeróbia de futebolistas por meio de teste de campo e teste laboratorial / Analysis of aerobic power of soccer players through field test and laboratory test / Análisis de la capacidad aeróbica de futbolistas por medio de test de campo y test en laboratório

Introdução: Há métodos diretos e indiretos que são utilizados pelos clubes de futebol para avaliar, acompanhar e determinar o VO2max dos jogadores, sendo este muito importante para o rendimento e a recuperação dos atletas durante uma partida. Objetivo: Avaliar o nível de correlação entre as medidas de VO2max por meio da análise direta de gases e do teste de campo Yo-Yo Intermitente Recovery Level 1 (Yo-YoIR1). Métodos: Participaram do estudo 24 jogadores de futebol da categoria SUB-20 de um clube do estado de São Paulo, Brasil, com estatura 1,72±0,08 m e massa corporal 61,17±9,18 kg, com no mínimo cinco anos de prática na modalidade. Os atletas realizaram o teste de análise direta dos gases em esteira ergométrica e após 48 horas foi realizado o Yo-Yo IR1. Resultados: Os resultados apontaram uma correlação significante entre os testes (r=0,524; p<0,01), porém o Yo-Yo IR1 subestimou as medidas de análise direta dos gases em laboratório (44,98ml/kg/min e 48,14ml/kg/min, respectivamente). Conclusão: Os resultados apontaram uma correlação moderada entre as medidas de VO2max, dessa forma pode-se utilizar ambos os testes para análise da potência aeróbia dos jogadores de futebol, desde que seja repetido o mesmo protocolo nas avaliações subsequentes. .

Introduction: There are direct and indirect methods that are used by soccer clubs to assess, monitor and determine the VO2max of soccer players, which is very important for the performance and recovery of athletes during a match. Objective: The aim of this study was to assess the level of the correlation between measures of VO2max by direct gas analysis and by the field test Yo-Yo Intermittent Recovery Level 1 (Yo-Yo IR1). Methods: The study included 24 Brazilian male soccer players from under 20 category, of a club in the State of São Paulo, Brazil with stature of 1.72 ± 0.08 meter and body mass of 61.17 ± 9.18 kg, with at least five years of practice in the sport. The athletes performed the direct analysis of gases test on a treadmill 48 hours later the Yo-Yo IR1 was performed. Results: The results revealed a significant correlation between tests (r=0.524; p<0.01), but Yo-Yo IR1 underestimated measures of direct analysis of gases in the laboratory (44.98ml/kg/min and 48.14ml/kg/min, respectively). Conclusion: The results showed a moderate correlation between measures of VO2max, that way both tests can be used to analyze the aerobic power of soccer players, since the same protocol is repeated in subsequent evaluations. .

Introducción: Los métodos directos e indirectos son utilizados por los clubes de fútbol para evaluar, monitorear y determinar el VO2max de los jugadores, lo que es muy importante para el rendimiento y la recuperación de los atletas durante un partido. Objetivo: Evaluar el nivel de correlación entre las medidas de VO2max de análisis directo de gases y la prueba de campo Yo-Yo Intermitente Recovery Nivel 1 (Yo-YoIR1). Métodos: El estudio incluyó a 24 futbolistas categoría SUB-20 de un club en el Estado de São Paulo, Brasil, con estatura de 1,72 ± 0,08 metro y masa corporal de 61,17 ± 9,18 Kg, con al menos cinco años de práctica en la modalidad. Los atletas realizaron el análisis directo de los gases en una caminadora y después de 48 horas se realizó el Yo-Yo IR1. Resultados: Los resultados revelaron una correlación significativa entre los ensayos (r = 0,524, p < 0,01), pero el Yo-Yo IR1 ha subestimado las mediciones de laboratorio del análisis directo de gases (44,98 ml/Kg/min. y 48,14 ml/Kg/min., respectivamente). Conclusión: Los resultados indicaron una correlación moderada entre las medidas de VO2max, de esta manera se pueden utilizar ambas las pruebas para analizar la capacidad aeróbica de los jugadores de fútbol, siempre que se repita el mismo protocolo en las evaluaciones posteriores. .

Hematological and biochemical markers of iron status in a male, young, physically active population.

The aim of this study was to establish reference intervals (RIs) for the hemogram and iron status biomarkers in a physically active population. The study population included male volunteers (n = 150) with an average age of 19 ± 1 years who had participated in a regular and controlled exercise program for four months. Blood samples were collected to determine hematological parameters using a Sysmex XE-5000 analyzer (Sysmex, Kobe, Japan). Iron, total iron-binding capacity (TIBC), transferrin saturation and ferritin, and high-sensitivity C-reactive protein (CRP) concentrations in serum samples were measured using commercial kits (Roche Diagnostics, GmbH, Mannheim, Germany) and a Roche/Hitachi 902 analyzer. The RIs were established using the RefVal program 4.1b. The leucocyte count, TIBC, and CRP and ferritin concentrations exhibited higher RIs compared with those in a nonphysically active population. Thirty volunteers (outliers) were removed from the reference population due to blood abnormalities. Among the outliers, 46% exhibited higher CRP concentrations and lower concentrations of iron and reticulocyte hemoglobin compared with the nonphysically active population (P < 0.001). Our results showed that it is important to establish RIs for certain laboratory parameters in a physically active population, especially for tests related to the inflammatory response and iron metabolism.

Time course of muscle damage and inflammatory responses to resistance training with eccentric overload in trained individuals.

The purpose of this study was to observe the time course of muscle damage and inflammatory responses following an eccentric overload resistance-training (EO) program. 3 females (23.8 ± 2.6 years; 70.9 ± 12.7 kg; 1.6 ± 0.08 m) and 5 males (23.8 ± 2.6 years; 75.1 ± 11.2 kg; 1.8 ± 0.1 m) underwent thirteen training sessions (4 × 8-10 eccentric-only repetitions-80% of eccentric 1RM, one-minute rest, 2x week(-1), during 7 weeks, for three exercises). Blood samples were collected prior to (Pre) and after two (P2), seven (P7), nine (P9), eleven (P11), and thirteen (P13) sessions, always 96 hours after last session. The reference change values (RCV) analysis was employed for comparing the responses, and the percentual differences between the serial results were calculated for each subject and compared with RCV(95%). Four subjects presented significant changes for creatine kinase at P2, and another two at P13; six for C-reactive protein at P2, and three at P11; two for neutrophils at P2, P4, and P13, respectively; and only one for white blood cells at P2, P4, P7, and P9, for lymphocyte at P7, P9, and P13, and for platelet at P4. We conclude that EO induced high magnitude of muscle damage and inflammatory responses in the initial phase of the program with subsequent attenuation.

Interaction between overtraining and the interindividual variability may (not) trigger muscle oxidative stress and cardiomyocyte apoptosis in rats.

Severe endurance training (overtraining) may cause underperformance related to muscle oxidative stress and cardiomyocyte alterations. Currently, such relationship has not been empirically established. In this study, Wistar rats (n = 19) underwent eight weeks of daily exercise sessions followed by three overtraining weeks in which the daily frequency of exercise sessions increased. After the 11th training week, eight rats exhibited a reduction of 38% in performance (nonfunctional overreaching group (NFOR)), whereas eleven rats exhibited an increase of 18% in performance (functional overreaching group (FOR)). The red gastrocnemius of NFOR presented significantly lower citrate synthase activity compared to FOR, but similar to that of the control. The activity of mitochondrial complex IV in NFOR was lower than that of the control and FOR. This impaired mitochondrial adaptation in NFOR was associated with increased antioxidant enzyme activities and increased lipid peroxidation (in muscle and plasma) relative to FOR and control. Cardiomyocyte apoptosis was higher in NFOR. Plasma creatine kinase levels were unchanged. We observed that some rats that presented evidence of muscle oxidative stress are also subject to cardiomyocyte apoptosis under endurance overtraining. Blood lipid peroxides may be a suitable biomarker for muscle oxidative stress that is unrelated to severe muscle damage.

Reference intervals for saliva analytes collected by a standardized method in a physically active population.

OBJECTIVES: Our aims were to test a liquid-based saliva collection system for total antioxidant status (TAS), uric acid (UA), total protein concentration (TP) and salivary alpha-amylase (SAA) activity; to determine if these analytes in serum and saliva are correlated in a physically active population and to establish reference intervals for these parameters. DESIGN AND METHODS: Participants in this study were 115 physically active males (18-20 years old). Saliva samples were collected using the Saliva Collection System (Greiner Bio-One) immediately before obtaining blood. Biochemical analyses were conducted using an Autolab Boehringer analyzer. RESULTS: We found a correlation between UA and TP concentrations in serum and saliva samples. The reference intervals for TP and SAA activity in the morning were lower than in the afternoon (p<0.0001). The reference intervals for UA and TAS did not vary with the time of collection. CONCLUSION: The establishment of reference intervals for these saliva constituents increases their diagnostic utility and allows for detection of physiological or pathological states.

Efeitos de um programa de exercícios na postura vertebral de indivíduos com lombalgia / Effects of an exercise training program on the vertebral posture of low back pain subjects

O objetivo do presente trabalho foi analisar os efeitos de um programa de exercícios na postura vertebral de dois indivíduos com lombalgia crônica inespecífica(29 e 38 anos; 1.80 e 1.86 m; 86 e 84 kg). A curvatura geométrica 2D da coluna, no plano sagital, foi quantificada com videogrametria na postura ortostática, na marcha (1.2; 1.5 e 1.8m/s) e na corrida (2.2; 2.6 e 3.0 m/s). Após o programa de exercícios, opadrão de movimento da coluna mudou. A amplitude de movimento diminuiu na região lombar. Ocorreu um aumento da lordose lombar e da cifose torácica. Além dessas alterações biomecânicas, houve diminuição do quadro álgico e melhora na função motora, sugerindo a adoção de um padrão de movimento mais apropriado. .

The aim of this work was to evaluate the effects of an exercise training program in the vertebral posture of two individuals with unspecific chronic low back pain (29 and 38 years; 1.80 and 1.86 m; 86 and 84 kg). The 2D geometric curvature ofthe vertebral column, in the sagittal plane, was quantified by videogrametry in the standing posture, walking (1.2, 1.5 and 1.8 m/s) and running (2.2, 2.6 and 3.0 m/s). The spine movement pattern changed after the intervention. The range of motion of the lumbar spine decreased. Furthermore, the lumbar lordosis and the thoracic kyphosis were increased. Associated to these, the pain decreased and it was an improvement of the motor function, suggesting a better movement pattern.

Time course of strength and power recovery after resistance training with different movement velocities.

The purpose of this study was to evaluate the time course of strength and power recovery after a single bout of strength training designed with fast and slow contraction velocities. Nineteen male subjects were randomly divided into 2 groups: the slow-velocity contraction (SV) group and the fast velocity contraction (FV) group. Resistance training protocols consisted of 5 sets of 12 repetition maximum (5 × 12RM) with 50 seconds of rest between sets and 2 minutes between exercises. Contraction velocity was controlled by the execution time for each repetition (SV-6 seconds to complete concentric and eccentric phases and for FV-1.5 seconds). Leg Press 45° 1RM (LP 1RM), horizontal countermovement jump (HCMJ), and right thigh circumference (TC) were accessed in 6 distinct moments: base (1 week before exercise), 0 (immediately after exercises), 24, 48, 72, and 96 hours after exercise protocol. The SV and FV presented significant LP 1RM decrements at 0, and these were still evident 24-48 hours postexercise. The magnitude of decline was significantly (p < 0.05) higher for FV. The SV and FV presented significant HCMJ decrements at 0, but only for FV were these still evident 24-72 hours postexercise. The SV and FV presented significant TC increments at 0, and these were still evident 24-48 hours postexercise for SV but for FV it continued up to 96 hours. The magnitude of increase was significantly (p < 0.05) higher for FV. In conclusion, the fast contraction velocity protocol resulted in greater decreases in LP 1RM and HCMJ performance, when compared with slow velocity. The results lead us to interpret that this variable may exert direct influence on acute muscle strength and power generation capacity.

Reproducibility of an incremental treadmill VO(2)max test with gas exchange analysis for runners.

The evaluation of performance through the application of adequate physical tests during a sportive season may be a useful tool to evaluate training adaptations and determine training intensities. For runners, treadmill incremental VO(2)max tests with gas exchange analysis have been widely used to determine maximal and submaximal parameters such as the ventilatory threshold (VT) and respiratory compensation point (RCP) running speed. However, these tests often differ in methodological characteristics (e.g., stage duration, grade, and speed increment size), and few studies have examined the reproducibility of their protocol. Therefore, the aim of this study was to verify the reproducibility and determine the running speeds related to maximal and submaximal parameters of a specific incremental maximum effort treadmill protocol for amateur runners. Eleven amateur male runners underwent 4 repetitions of the protocol (25-second stages, each increasing by 0.3 km·h in running speed while the treadmill grade remained fixed at 1%) after 3 minutes of warm-up at 8-8.5 km·h. We found no significant differences in any of the analyzed parameters, including VT, RCP, and VO(2)max during the 4 repetitions (p > 0.05). Further, the results related to running speed showed high within-subject reproducibility (coefficient of variation < 5.2%). The typical error (TE) values for running speed related to VT (TE = 0.62 km·h), RCP (TE = 0.35 km·h), and VO(2)max (TE = 0.43 km·h) indicated high sensitivity and reproducibility of this protocol. We conclude that this VO(2)max protocol facilitates a clear determination of the running speeds related to VT, RCP, and VO(2)max and has the potential to enable the evaluation of small training effects on maximal and submaximal parameters.

Estudo dos efeitos de temporada de treinamento físico sobre a Performance de uma equipe de handebol feminino sub-21 / Study of the effect of a physical training season on performance of a women's under 21 handball team

O handebol é um esporte que demanda resistência associada a ações rápidas e potentes, como saltos, bloqueios, sprints e arremessos. O objetivo deste estudo foi avaliar os efeitos de treinamento físico sistematizado de 38 semanas aplicado em uma equipe de handebol feminino sub-21 sobre a potência de membros superiores e inferiores, velocidade e resistência de sprints de 30m. A periodização consistiu de adaptação da teoria de cargas concentradas e objetivou dois picos de performance durante a temporada, com seis coletas de dados. Os valores de mediana e amplitude de variação dos dados (entre parênteses) para o teste de arremesso de medicine ball de 3kg foram: 2,98m (2,15-3,50), 2,84m (2,43-3,20), 2,90m (2,60-3,38), 3,10 (2,83-3,81), 2,84 (2,55-3,57) e 3,34 (2,93-3,83). Para o teste de salto triplo horizontal alternado: 5,60m (4,93-6,58), 5,37m (5,04-6,38), 5,36m (4,93-6,12), 5,65m (4,80-6,78), 5,63m (5,00-6,40) e 5,83m (5,14-6,05). Para o teste de velocidade de sprint de 30m: 5,8m/s (5,45-6,44), 6,64m/s (6,24-7,09), 5,65m/s (5,17-5,95) (não houve coleta IV para esta capacidade), 6,19m/s (5,57-6,26) e 5,83m/s (5,14-6,05). Para o número de sprints até queda de 10 por cento velocidade de 30m: 4 (4-6), 5 (4-9), 4,5 (4-16) (não houve coleta IV para esta capacidade), 6 (4-12) e 5 (4-5). Observamos diferenças estatisticamente significativas nos testes de arremesso de medicine ball de 3kg e salto triplo horizontal em relação aos testes do início da temporada (p < 0,05) em pelo menos um dos períodos planejados para obtenção do pico de performance, sem melhoras significativas na velocidade média e resistência de sprints de 30m. O treinamento aplicado foi eficiente para a melhoria do condicionamento físico específico nos picos de performance, propiciando também melhor ajuste no treinamento para a próxima temporada.

Handball is a sport that demands endurance associated with fast and powerful actions such as jumps, blocks, sprints and throws. The aim of this study was to evaluate the effects of a 38-week systematic physical training applied to a women's under 21 handball team on upper and lower limb power, 30m sprints speed and endurance. The periodization applied was an adaptation of the Verkhoshansky theory, and aimed at two performance peaks during the season with six data collections. The median and range values for three kg medicine ball throwing was: 2.98m (2.15-3.50); 2.84m (2.43-3.20); 2.90m (2.60-3.38); 3.10 (2.83-3.81); 2.84 (2.55-3.57) and 3.34 (2.93-3.83). Regarding the three-pass running test: 5.60m (4.93-6.58); 5.37m (5.04-6.38); 5.36m (4.93-6.12); 5.65m (4.80-6.78); 5.63m (5.00-6.40) and 5.83m (5.14-6.05). Regarding the 30-m sprint test: 5.8m/s (5.45-6.44); 6,64 m/s (6,24-7,09); 5.65m/s (5.17-5.95); (there was not IV moment for this test); 6.19 m/s (5.57-6.26) and 5.83 (5.14-6.05).Regarding the 30-m sprint endurance test until 10 percent decrease: 4 sprints (4-6); 5 sprints (4-9); 4,5 sprints (4-16); (there was not IV moment for this test); 6 sprints (4-12) and 5 sprints (4-5). Significant differences (p<0.05) were observed in three kg medicine ball throwing and three-pass running tests at least in one of the performance peak planned, with no significant differences in 30-m sprint speed or endurance tests. The applied physical training was efficient at improving the specific physical fitness in the performance peaks, as well as giving support for better physical training adjustment for the upcoming season.

Reference change values of blood analytes from physically active subjects.

The analysis of blood constituents allows the detection of various physiological or pathological states when their values are increased or decreased in relation to a well-defined reference group or to themselves if monitored longitudinally. In the latter case, it is important to know the reference change value (RCV) or critical difference, which defines the percentage change that should be exceeded-given the analytical and biological variations inherent to a particular test, in that there is a significant difference between the two consecutive measurements. Our objective was to calculate the biological variation, analytical variation and RCV of the biochemical and hematological parameters in subjects undergoing 4 months of regular aerobic training. Blood samples (10 mL) were collected monthly from 56 male subjects (17-19 years old). Creatine kinase and aspartate aminotransferase activities, total cholesterol, triglycerides, uric acid, C-reactive protein, alpha-1-acid glycoprotein, creatinine and urea concentrations were measured in sera using an Autolab Boehringer analyzer. Hemogram were obtained from total blood using KX-21 N SYSMEX equipment. The RCV values for leukocytes and all biochemical analytes were elevated compared to the literature values of sedentary subjects. On the other hand, the RCV values for red blood cell count were slightly lower in physically active than in sedentary individuals. Knowledge of analyte RCV values within physically active subjects should improve the sensitivity/specificity of the hematological and biochemical alterations induced by training or the use of recombinant form of erythropoietin through blood parameter analysis, particularly in cases of longitudinal monitoring.

Development and characterization of an overtraining animal model.

PURPOSE: Development of an endurance training-overtraining protocol for Wistar rats that includes increased workload and is characterized by analyses of performance and biomarkers. METHODS: The running protocol lasted 11 wk: 8 wk of daily exercise sessions followed by 3 wk of increasing training frequency (two, three, and four times), with decreasing recovery time between sessions (4, 3, and 2 h) to cause an imbalance between overload and recovery. The performance tests were made before training (T1) and after the 4th (T2), 8th (T3), 9th (T4), 10th (T5), and 11th (T6) training weeks. All rats showed significantly increased performance at T4, at which time eight rats, termed the trained group (Tr), were sacrificed for blood and muscle assays. After T6, two groups were distinguishable by differences in the slope (alpha) of a line fitted to the individual performances at T4, T5, and T6: nonfunctional overreaching (NFOR; alpha < -15.05 kg x m) and functional overreaching (FOR; alpha >or= -15.05 kg x m). RESULTS: Data were presented as mean +/- SD. FOR maintained the performance at T6 similar to Tr at T4 (530.6 +/- 85.3 and 487.5 +/- 61.4 kg x m, respectively). The FOR and the Tr groups showed higher muscle citrate synthase activity (approximately 40%) and plasma glutamine/glutamate ratio (Gm/Ga; 4.5 +/- 1.7 and 4.5 +/- 0.9, respectively) than the sedentary control (CO) group (2.8 +/- 0.5). The NFOR group lost the performance acquired at T4 (407.3 +/- 88.2 kg x m) after T6 (280.5 +/- 93.1 kg x m) and exhibited sustained leukocytosis. NFOR's Gm/Ga (3.1 +/- 0.2) and muscle citrate synthase activity were similar to CO values. CONCLUSIONS: The decline in performance in the NFOR group could be related to the decrease in muscle oxidative capacity. We observed a trend in the Gm/Ga and leukocytosis that is similar to what has been sometimes observed in overtrained humans. This controlled training-overtraining animal model may be useful for seeking causative mechanisms of performance decline.

The upper values of plasma creatine kinase of professional soccer players during the Brazilian National Championship.

The current schedule of the Brazilian Soccer Championship may not give players enough recovery time between games. This could increase the chances of muscle damage and impaired performance. We hypothesized that plasma creatine kinase (CK) activity could be a reliable indirect marker of muscle overload in soccer players, so we sought to identify the reference values for upper limits of CK activity during a real-life elite competition. This study analyzed changes in plasma CK activity in 128 professional soccer players at different times during the Brazilian Championship. The upper limits of the 97.5th and 90th percentiles determined for CK activity were 1.338U/L and 975U/L, respectively, markedly higher than values previously reported in the literature. We also evaluated a team monthly throughout the Championship. The upper limit of the 90th percentile, 975U/L, was taken as the decision limit. Six players showing plasma CK values higher than this were asked to decrease their training for 1 week. These players presented lower CK values afterwards. Only one player with a CK value higher than the decision limit (1800U/L 1 day before a game) played on the field and was unfortunately injured during the game. The CK activity in all the other players showed a significant decrease over the course of the Championship, and the values became more homogeneous at the end. The results presented here suggest that plasma CK upper limit values can be used as a practical alternative for early detection of muscle overload in competing soccer players.

Understanding the glycemic index and glycemic load and their practical applications.

We have introduced the study of synthesis pathways using two experiments: 1-the determination of the glycemic index (GI) of some foods and the effects of fiber and fat on the GI; 2-the determination of blood glucose levels after the ingestion of meals with high and low glycemic loads (GL). After a practice assembly, when the foods and meals that were eaten by the students were tallied, the students were divided into groups. At the next class, three members of each group, who had fasted for 8 hr, ingested 50 g of carbohydrate in food or a meal. After ingestion, the blood glucose was measured with a portable device every 30 min for a period of 2 hr. Discussion of the data obtained in experiment 1 allowed the students to understand the mechanism of action of insulin and to understand how the GI, as presented in the literature, is determined. The students also concluded that the addition of fiber to food reduces the glycemic response even with high GI foods, and these results could be a useful strategy for diet prescription. Discussion of experiment 2 allowed the students to understand that the amount of food intake is a determining factor for the glycemic response and subsequent release of insulin. These experimental observations allowed the students to transfer theoretical knowledge to their daily lives very easily. The students approved the classes and felt encouraged to study the synthesis pathways and metabolic integration in the fed state.

Interpretação metabólica dos parâmetros ventilatórios obtidos durante um teste de esforço máximo e sua aplicabilidade no esporte / Metabolic interpretation of ventilatory parameters during maximal effort test and their applicability to sports

A determinação das velocidades atingidas no limiar ventilatório (LV), ponto de compensação respiratório(PCR) e consumo máximo de O2 (VO2max) através de um teste de esforço máximo, é uma ferramenta importante para aaplicação de intensidades de treinamento específicas e individualizadas. Mas para poder interpretar os dados de uma forma abrangente, também é importante o entendimento das respostas metabólicas presentes no ajuste dos sistemas de transporte e utilização de O2 e produção de CO2 durante a realização do teste. Esta revisão apresenta um panorama das respostas metabólicas que acontecem durante a realização de um teste de esforço máximo hipotético, e a aplicabilidade dos valores obtidos no treinamento de atletas.

One important tool for producing specific and individualized training intensities is to determine ventilatory threshold (VT), respiratory compensation point (RCP) and maximal oxygen uptake (VO2max) by means of maximum effort testing. However, in order to be able to interpret these data in a wide-ranging manner, it is also important to understand the metabolic responses that occur during the test as the systems transporting and utilizing O2 and producing CO2 adjust. This review article presents an overview of the metabolic responses that take place during a hypothetical maximum effort test, and the applicability of the figures thus obtained to the training of athletes.

Apparatus for measuring rat body volume: a methodological proposition.

We propose a communicating-vessels system to measure body volume in live rats through water level detection by hydrostatic weighing. The reproducibility, accuracy, linearity, and reliability of this apparatus were evaluated in two tests using previously weighed water or six aluminum cylinders of known volume after proper system calibration. The applicability of this apparatus to measurement of live animals (Wistar rats) was tested in a transversal experiment with five rats, anesthetized and nonanesthetized. We took 18 measurements of the volume under each condition (anesthetized and nonanesthetized), totaling 90 measurements. The addition of water volumes (50-700 ml) produced a regression equation with a slope of 1.0006 +/- 0.0017, intercept of 0.75 +/- 0.81 (R(2) = 0.99999, standard error of estimate = 0.58 ml), and bias of approximately 1 ml. The differences between cylinders of known volumes and volumes calculated by the system were <0.4 ml. Mean volume errors were 0.01-0.07%. Among the live models, the difference between the volumes obtained for anesthetized and nonanesthetized rats was 0.31 +/- 2.34 (SD) ml (n = 90). These data showed that animal movement does not interfere with the volume measured by the proposed apparatus, and neither anesthesia nor fur shaving is needed for this procedure. Nevertheless, some effort should be taken to eliminate air bubbles trapped in the apparatus or the fur. The proposed apparatus for measuring rat body volume is inexpensive and may be useful for a range of scientific purposes.