Skeletal Maturation and Aerobic Performance in Young Soccer Players from Professional Academies.

The contribution of chronological age, skeletal age (Fels method) and body size to variance in peak velocity derived from the Carminatti Test was examined in 3 competitive age groups of Brazilian male soccer players: 10-11 years (U-12, n=15), 12-13 years (U-14, n=54) and 14-15 years (U-16, n=23). Body size and soccer-specific aerobic fitness were measured. Body composition was predicted from skinfolds. Analysis of variance and covariance (controlling for chronological age) were used to compare soccer players by age group and by skeletal maturity status within of each age group, respectively. Relative skeletal age (skeletal age minus chronological age), body size, estimated fat-free mass and performance on the Carminatti Test increased significantly with age. Carminatti Test performance did not differ among players of contrasting skeletal maturity status in the 3 age groups. Results of multiple linear regressions indicated fat mass (negative) and chronological age (positive) were significant predictors of peak velocity derived from the Carminatti Test, whereas skeletal age was not a significant predictor. In conclusion, the Carminatti Test appears to be a potentially interesting field protocol to assess intermittent endurance running capacity in youth soccer programs since it is independent of biological maturity status.

Consumo de oxigênio durante ciclismo na máxima fase estável de lactato sanguíneo até a exaustão: modelo contínuo vs. intermitente / Consumo de oxígeno durante ciclismo en la máxima fase estable de lactato sanguíneo hasta el agotamiento: modelo continuo vs. intermitente / Oxygen uptake during cycling at maximal lactate steady state to exhaustion: continuous vs. intermittent model

Objetivo. Analisar o consumo de oxigênio (VO2) acumulado e o tempo em que o VO2 é mantido (TMcg) em elevados valores durante o exercício realizado na máxima fase estável de lactato (MLSS) determinada de forma contínua (MLSScon) e intermitente (MLSSint) até à exaustão. Método. Catorze ciclistas treinados realizaram um teste incremental máximo no cicloergômetro; 2‐5 testes contínuos e 2‐4 testes intermitentes, para determinação da MLSScon e MLSSint, respectivamente; por fim mais 2 testes até a exaustão (TTE) (contínuo e intermitente), conduzidos nas respectivas cargas de MLSS. Resultados. O TTE contínuo foi significativamente menor do que o TTE intermitente (54,7 ± 10,9 vs. 67,8 ± 14,3, respectivamente; p = 0,001). O VO2 da carga (VO2cg) foi significantemente maior na condição intermitente (p < 0,05), em ambas as situações (MLSS e TTE). Por outro lado, o TMcg e o VO2 acumulado na carga (VO2ACcg) foram maiores na condição contínua (p < 0,0001), em ambas as situações. O total de VO2 acumulado (VO2ACt) foi similar entre as condições contínuas e intermitentes (104,7 ± 8,7 L vs. 103,9 ± 41,1 L para a MLSS e 193,8 ± 41,1 L vs. 226,4 ± 53,0 L para o TTE, respectivamente). Conclusão. Os exercícios contínuo e intermitente realizados com a mesma duração ou até a exaustão, e em condições metabólicas similares, apresentam valores de VO2ACt similares, embora o TMcg e o VO2ACcg sejam inferiores no exercício intermitente (AU)

Objetivo. Analizar el consumo de oxígeno (VO2) acumulado y el tiempo en que el VO2 es mantenido (TMcg) en valores elevados, durante el ejercicio realizado en la máxima fase estable de lactato (MLSS), determinada de forma continua (MLSScon) e intermitente (MLSSint) hasta el agotamiento. Método. Catorce ciclistas entrenados realizaron un test incremental máximo en el cicloergómetro; 2‐5 test continuos y 2‐4 test intermitentes, para determinación de la MLSScon y MLSSint, respectivamente; por último realizaron 2 test hasta el agotamiento (TTE) (continuo e intermitente), a las respectivas cargas de MLSS. Resultados. El TTE continuo fue significativamente menor que el TTE intermitente (54,7 ± 10,9 vs. 67,8 ± 14,3, respectivamente; p = 0,001). El VO2 de la carga (VO2cg) fue significativamente mayor en la condición intermitente (p < 0,05), en ambas situaciones (MLSS y TTE). Por otro lado, el TMcg y el VO2 acumulado en la carga (VO2ACcg) fueron mayores en la condición continua (p < 0,0001), en ambas las situaciones. El total de VO2 acumulado (VO2ACt) fue similar entre las condiciones continuas e intermitentes (104,7 ± 8,7 L vs. 103,9 ± 41,1 L para a MLSS y 193,8 ± 44,1 L vs. 226,4 ± 53,0 L para el TTE, respectivamente). Conclusión. Los ejercicios continuo e intermitente realizados con la misma duración o hasta el agotamiento, y en condiciones metabólicas similares presentan valores de VO2ACt similares, aunque el TMcg y el VO2ACcg sean inferiores en el ejercicio intermitente (AU)

Objective. The aim of this study was to analyse the accumulated oxygen uptake (VO2), as well the maintained time (TMcg) at high levels during a maximal lactate steady state (MLSS) exercise, determined in continuous (MLSScon) and intermittent (MLSSint) modes, until exhaustion. Method. Fourteen trained cyclists performed an incremental maximal testing; 2‐5 continuous and 2‐4 intermittent constant workload trials, in order to identify the MLSScon and MLSSint, respectively; two tests until exhaustion (TTE) (continuous and intermittent) were conducted using their respective MLSS workloads. Results. The continuous TTE was significantly lower than TTE at intermittent protocol (54.7 ± 10.9 vs. 67.8 ± 14.3 min; p = 0.001). The VO2 at target workload (VO2cg) was higher at intermittent exercise (p < 0.05), at both situations (MLSS and TTE). On the other hand, TMcg and the VO2 accumulated in MLSS workloads (VO2ACcg) were higher during continuous mode (p < 0.0001), at both situations. The total VO2 accumulated (VO2ACt) was similar between intermittent and continuous cycling (MLSS: 104.7 ± 8.7 L vs. 103.9 ± 41.1 L and TTE: 193.8 ± 41.1 L vs. 226.4 ± 53.0 L, respectively). Conclusion. When MLSS continuous and intermittent were performed with same duration or until exhaustion, the VO2ACt was similar, although the TMcg and VO2ACcg were smaller during intermittent exercise (AU)

Efeitos do treinamento intervalado em variáveis fisiológicas e na performance de ciclistas competitivos / Efectos del entrenamiento de intervalos en las variables fisiológicas y el rendimiento en ciclistas competitivos / Effects of interval training on physiological variables and performance in competitive cyclists

Objetivo: O presente estudo teve como objetivo analisar os efeitos de diferentes métodos de treinamento intervalado (TI) nos parâmetros fisiológicos e no desempenho de ciclistas competitivos. Método: A classificação dos métodos de TI foram: a) sub-máximo (TIsub), b) máximo (TImax) e c ) supra-máximo (TIsup). A estratégia de busca incluiu os seguintes termos: treinamento intervalado, treinamento intervalado em ciclistas, treinamento intervalado de alta intensidade, treinamento intervalado de alta intensidade em ciclistas e sprint. Foram consultadas as seguinte bases de dados: PubMed, Google Scholar e SPORTDiscus. Para isso, foi realizada uma pesquisa entre julho de 2011 e fevereiro de 2012. Resultados: Dentre as diferentes metodologias de TI em ciclistas competitivos, todos os métodos foram suficientes para demonstrar melhorias na potência aeróbia máxima (Pmax), consumo máximo de oxigênio (VO2max), limiares fisiológicos, tempo de exaustão (Tlim) e contra-relógio de 40 km no ciclismo (CR40km ) em ciclistas competitivos. Conclusão: Portanto, os três métodos de TI demonstraram que são necessárias de 6-8 sessões de treino durante um período de 4-6 semanas para se obter ganhos nas variáveis fisiológicas e na performance em ciclistas competitivos

Objetivo. En la presente investigación hemos planteado como objetivo analizar los efectos de diferentes métodos de entrenamiento de intervalos (EI) en los parámetros de la capacidad fisiológica y el desempeño de los ciclistas de competición. Método. La clasificación de los métodos de EI es: a) sub-máxima (EIsub), b) máxima (EImax), y c) supramáxima (EIsup). La estrategia de búsqueda incluyó los términos siguientes: entrenamiento de intervalos, entrenamiento de intervalos en el ciclismo, entrenamiento de intervalo de alta intensidad, entrenamiento de intervalo de alta intensidad en el ciclismo y sprint. Para este fin, se realizó una búsqueda entre julio de 2011 y febrero de 2012 en las bases de datos: PubMed y Google Scholar SPORTDiscus. Resultados. Entre las diferentes metodologías de EI en ciclistas de competición, todos los métodos fueron suficientes para demostrar mejoras de la potencia aeróbica máxima (Pmax), el consumo máximo de oxígeno (VO2max), los umbrales fisiológicos, tiempo hasta el agotamiento (Tlim) y la prueba de 40 km de contrarreloj de ciclismo (CR40km). Conclusión. Los tres métodos de EI mostraron que es necesario 6-8 sesiones de entrenamiento durante un período de 4-6 semanas para que los ciclistas entrenados mejoraron las variables fisiológicas y de rendimiento (AU)

Objective. The aim of this study was to analyze the effects of different methods of interval training (IT) on physiological variables and performance in competitive cyclists. Method. The classification of the IT methods were: a) sub-maximal (ITsub), b) high (ITmax) and c) supramaximum (ITsup). The search strategy included the following terms: interval training, interval training on cycling, high intensity interval training, high intensity interval training in cycling and sprint. We choose for the followed databases: PubMed, Google Scholar and SPORTDiscus. For this purpose, a search were in a period between July 2011 and February 2012. Results. The different methods of IT increased maximal aerobic power (Pmax), maximum oxygen consumption (VO2max), physiological thresholds, time to exhaustion (Tlim) and 40-km cycling time trial CR40km ) in competitive cyclists. Conclusion. Therefore, the three methods of IT showed that 6-8 sessions of training during 4-6 weeks isnecessary to improve physiological variables and cycling performance in competitive cyclists (AU)

Neuroprotective and neuroregenerative effects of low-intensity aerobic exercise on sciatic nerve crush injury in mice.

Here, we established a program of low-intensity aerobic exercise and compared the effects of exercise preoperative, postoperative, and a combination of both pre- and postoperative protocols on recovery from sciatic nerve crush injury in mice using behavioral, biochemical, and morphological assays. Sciatic nerve crush was performed in adult male mice. The animals were submitted to preoperative (for 2 weeks), postoperative (for 2 weeks), and a combination of preoperative-postoperative (for 4 weeks) training protocols. During the training period, functional recovery was monitored using the Sciatic Functional Index, the Sciatic Static Index, and mechanical and cold hypersensitivity analyses. Morphological and biochemical alterations were analyzed on the 14th day post-crushing. The functional recovery values of all of the exercised groups were significantly better than the nonexercised group. Biochemically, all of the exercise groups showed a reduction in the increase of interleukin-1ß (IL-1ß) in the sciatic nerve and in the IL-1ß and interleukin-6 receptor (IL-6R) levels in the spinal cord. However, the levels of tumor necrosis factor alpha (TNF-α) decreased only in the postoperative group and in the combination exercise protocols. In the morphological analysis, the combination exercise subjects presented an increase in fiber and axon diameter, in the myelination degree and in the number of myelinated fibers. The present study showed that pre- and postoperative exercise achieved values for functional and morphological sciatic nerve regeneration that were significantly better than either the preoperative or postoperative protocols. This experimental study suggests that physical exercise can restore motor and nerve function to a substantial degree when performed using a prophylactic and therapeutic approach.

Molecular aspects involved in swimming exercise training reducing anhedonia in a rat model of depression.

Patients suffering from depression frequently display hyperactivity of the hypothalamic-pituitary-adrenal axis (HPA) resulting in elevated cortisol levels. One main symptom of this condition is anhedonia. There is evidence that exercise training can be used as a rehabilitative intervention in the treatment of depressive disorders. In this scenario, the aim of the present study was to assess the effect of an aerobic exercise training protocol on the depressive-like behavior, anhedonia, induced by repeated dexamethasone administration. The study was carried out on adult male Wistar rats randomly divided into four groups: the "control group" (C), "exercise group" (E), "dexamethasone group" (D) and the "dexamethasone plus exercise group" (DE). The exercise training consisted of swimming (1 h/d, 5 d/wk) for 3 weeks, with an overload of 5% of the rat body weight. Every day rats were injected with either dexamethasone (D/DE) or saline solution (C/E). Proper positive controls, using fluoxetine, were run in parallel. Decreased blood corticosterone levels, reduced adrenal cholesterol synthesis and adrenal weight (HPA disruption), reduced preference for sucrose consumption and increased immobility time (depressive-like behavior), marked hippocampal DNA oxidation, increased IL-10 and total brain-derived neurotrophic factor (BDNF; pro-plus mature-forms) and a severe loss of body mass characterized the dexamethasone-treated animals. Besides increasing testosterone blood concentrations, the swim training protected depressive rats from the anhedonic state, following the same profile as fluoxetine, and also from the dexamethasone-induced impaired neurochemistry. The data indicate that physical exercise could be a useful tool in preventing and treating depressive disorders.

Effects of strength training on running economy.

The objective of this study was to compare the effect of different strength training protocols added to endurance training on running economy (RE). Sixteen well-trained runners (27.4 +/- 4.4 years; 62.7 +/- 4.3 kg; 166.1 +/- 5.0 cm), were randomized into two groups: explosive strength training (EST) (n = 9) and heavy weight strength training (HWT) (n = 7) group. They performed the following tests before and after 4 weeks of training: 1) incremental treadmill test to exhaustion to determine of peak oxygen uptake and the velocity corresponding to 3.5 mM of blood lactate concentration; 2) submaximal constant-intensity test to determine RE; 3) maximal countermovement jump test and; 4) one repetition maximal strength test in leg press. After the training period, there was an improvement in RE only in the HWT group (HWT = 47.3 +/- 6.8 vs. 44.3 +/- 4.9 ml . kg (-1) . min (-1); EST = 46.4 +/- 4.1 vs. 45.5 +/- 4.1 ml . kg (-1) . min (-1)). In conclusion, a short period of traditional strength training can improve RE in well-trained runners, but this improvement can be dependent on the strength training characteristics. When comparing to explosive training performed in the same equipment, heavy weight training seems to be more efficient for the improvement of RE.