Anemia and nutritional aspects in adolescent athletes: a cross-sectional study in a reference sport organization / Anemia e aspectos nutricionais em atletas adolescentes: estudo transversal em agremiação desportiva de referência nacional

ABSTRACT Objective: To assess the association between anemia and nutritional aspects in adolescent athletes from a large sport club. Methods: This is a cross-sectional study, involving 298 athletes aged between 10 and 17 years, submitted to measurement of skin folds, weight and height, and collection of capillary blood in duplicate to determine hemoglobin values. It was carried out in a random sample composed of athletes from eight sport modalities. Results: Regarding nutritional status, 10.1% of athletes were overweight based on body mass index and 70 (23.5%) athletes had a percentage of body fat classified as high or very high. The prevalence of anemia was 16.4%, being more prevalent in judo (37.1%), basketball (34%) and futsal (20.5%) athletes. Low hemoglobin levels were significantly associated with shorter stature (p=0.006). Conclusions: There was a significant association between anemia and short stature, suggesting that the athlete's height-weight development may be affected in suboptimal conditions of oxygen distribution.

RESUMO Objetivo: Avaliar a associação entre anemia e aspectos nutricionais em atletas adolescentes de um clube desportivo de grande porte. Métodos: Trata-se de estudo de corte transversal que envolveu 298 atletas com idades entre 10 e 17 anos, submetidos à aferição de dobras cutâneas, peso e altura, além de coleta de sangue capilar em duplicata para a determinação dos valores de hemoglobina. Foi realizado em amostra aleatória composta de atletas oriundos de oito modalidades esportivas. Resultados: Em relação ao estado nutricional, 10,1% dos atletas apresentaram excesso de peso com base no índice de massa corpórea e 70 (23,5%) atletas estavam com porcentagem de gordura corporal classificada como alta ou muito alta. A prevalência de anemia foi de 16,4%, mais prevalente nos atletas do judô (37,1%), basquete (34%) e futsal (20,5%). Níveis baixos de hemoglobina foram associados à menor estatura (p=0,006). Conclusões: Observou-se associação significativa entre anemia e baixa estatura, o que sugere que o desenvolvimento pôndero-estatural do atleta pode ser afetado em condições subótimas de distribuição de oxigênio.

Anemia and nutritional aspects in adolescent athletes: a cross-sectional study in a reference sport organization.

OBJECTIVE: To assess the association between anemia and nutritional aspects in adolescent athletes from a large sport club. METHODS: This is a cross-sectional study, involving 298 athletes aged between 10 and 17 years, submitted to measurement of skin folds, weight and height, and collection of capillary blood in duplicate to determine hemoglobin values. It was carried out in a random sample composed of athletes from eight sport modalities. RESULTS: Regarding nutritional status, 10.1% of athletes were overweight based on body mass index and 70 (23.5%) athletes had a percentage of body fat classified as high or very high. The prevalence of anemia was 16.4%, being more prevalent in judo (37.1%), basketball (34%) and futsal (20.5%) athletes. Low hemoglobin levels were significantly associated with shorter stature (p=0.006). CONCLUSIONS: There was a significant association between anemia and short stature, suggesting that the athlete's height-weight development may be affected in suboptimal conditions of oxygen distribution.

Analysis of the small-sided games in volleyball: an ecological approach / Análise dos pequenos jogos no voleibol: uma abordagem ecológica

Abstract The aim of the present study was to compare the tactical and technical behavior of beginner players in volleyball side-out between four distinct situations of reduced games with different area/player ratios: 4.5 m2 (3.0 m x 3.0 m), 8.0 m2 (4.0 m x 4.0 m), 10.58 m2 (4.6 m x 4.6 m), and 13.52 m2 (5.2 m x 5.2 m). We analyzed 76 games played by 16 players with a mean age of 12.2 ± 0.5 years and experience of 1.2 ± 0.8 years of practice. Tactical and technical behavior was analyzed using an adaptation of the Game Performance Analysis Instrument (GPAI). The analysis was conducted for passing, setting and attacking according to the components related to technical adjustment, technical efficiency and decision-making. The results showed that players presented higher technical and tactical indexes in the passing and setting skills in 4.6 m x 4.6 m and 5.2 m x 5.2 m situations. Also, in the 3.0 m x 3.0 m situation higher technical indexes were found for the attacking. No differences were found in the tactical behavior of attacking for tested situations. We conclude that the environmental constraints imposed by the small-sided games imply distinct technical and technical behaviors. Thus, the pedagogical strategy of using small-sided games for the teaching of volleyball for beginner players must be associated with the intended objectives for each basic volleyball skills.

Resumo O objetivo do presente estudo foi comparar o comportamento tático e técnico de jogadores iniciantes no voleibol no side-out de acordo com quatro situações distintas de jogos reduzidos com diferentes relações área/jogador: 4,5 m2 (3,0 m x 3,0 m), 8,0 m2 (4,0 m x 4,0 m), 10,58 m2 (4,6 m x 4,6 m) e 13,52 m2 (5,2 m x 5,2 m). Foram analisados ​​76 jogos disputados por 16 jogadores com média de idade de 12,2 ± 0,5 anos e experiência de 1,2 ± 0,8 anos de prática. O comportamento tático e técnico foi analisado por meio de uma adaptação do Game Performance Analysis Instrument. A análise foi realizada para a recepção, o levantamento e o ataque de acordo com os componentes relacionados ao ajuste técnico, eficiência técnica e a tomada de decisão. Os resultados mostraram que os jogadores apresentaram índices táticos e técnicos superiores nas habilidades de recepção e levantamento nas situações de 4,6 m x 4,6 m e 5,2 m x 5,2 m. Além disso, na situação de 3,0 m x 3,0 m foram encontrados índices técnicos mais elevados para o ataque. Não foram encontradas diferenças no comportamento tático do ataque para as situações analisadas. Concluímos que as restrições ambientais, impostas pelos pequenos jogos, implicam em comportamentos táticos e técnicos distintos. Assim, a estratégia pedagógica de utilização de pequenos jogos para o ensino do voleibol para jogadores iniciantes deve estar associada aos objetivos pretendidos para cada uma das habilidades básicas do voleibol.

Relative age effect and dropout causes in a multisport club setting. Is there a special reason to give up?

The aim of the present study was 1) compare the drop-out rates between athletes born in different trimesters of the competitive year from different sports and 2) identify the causes pointed by the dropped-out athletes born in different selection year trimesters to disengage from the competitive sports environment. Methods: Data from 966 athletes who left the competitive sports context were analyzed under the Relative Age Effect (RAE) theoretical framework during 3 consecutive seasons. The drop-out rate and the reason to quit the competitive environment were analyzed by a routine club questionnaire. Results: An expected reverse RAE on drop-out rates was identified, in which the early born athletes were overrepresented (p<0.001). Regarding the reasons to disengage from competitive sports environment, no reason emerged as the main cause to dropout between athletes born in different selection year trimester. Conclusion: It was concluded that despite the common assumption that personal psychological issues related to RAE in late born athletes are important factors influencing sports disengagement, the relationship between drop-out and RAE is more complex and multifactorial.(AU)

O conhecimento tático produto de métodos de ensino combinados e aplicados em sequências inversas no voleibol / Tactical knowledge as a product of the combination of different teaching methods employed in inversesequences in volleyball

O objetivo desta pesquisa foi investigar as diferenças entre os métodos de ensino situacional e tradicional no desenvolvimento do conhecimento tático declarativo e processual nas sessões de treinamento de voleibol, bem como observar a influência da ordem de aplicação desses métodos no conhecimento tático. A amostra foi composta por 36 estudantes (sexo masculino - faixa etária de 12 a 14 anos), sendo 22 destes inscritos nas equipes escolares de voleibol e 14 não praticantes de voleibol (grupo controle). Um grupo iniciou o processo de ensino-aprendizagem-treinamento pelo método situacional (GST) e outro pelo método tradicional (GTS). Ao final de 15 sessões o método foi invertido e realizado o mesmo número de sessões. Para confirmar a execução do método de ensino foi empregada a observação e categorização dos treinos (STEFANELLO, 1999). Para a avaliação do conhecimento processual foi utilizado o teste KORA (MEMMERT, 2002), no parâmetro tático reconhecer espaços. Já no declarativo usou-se o teste de Conhecimento Tático em Situação de Ataque de Rede (PAULA, 2000). Os três grupos no pré-teste demonstram estar inicialmente no mesmo patamar de conhecimento tático declarativo e processual. No GST, ao se aplicar o método situacional (referente às 15 sessões iniciais), não houve diferença significativa no conhecimento tático declarativo, mas houve no processual convergente e divergente. Já no GTS, ao empregar o método tradicional, não se confirmou o desenvolvimento de nenhum dos conhecimentos táticos. Ao efetuar a inversão do método de ensino, no GST (30 sessões na sequência situacional-tradicional) foi apurada melhoria significativa de ambos os conhecimentos táticos processuais. Entretanto, o mesmo não ocorreu no GTS na sequência tradicional-situacional. Os resultados indicam que a sequência de treinamentos referentes ao GST proporcionou melhoras relevantes na inteligência e na criatividade tática dos jogadores.

The purpose of this study was to investigate the differences between traditional and situational teaching methods on the acquisition of procedural and declarative tactical knowledge in volleyball sessions of training, and to verify the influence of the order of employment of these methods on tactical knowledge. The sample was composed by 36 students (male/aged 12-14 years), 22 of them were school volleyball players and the other 14 were not volleyball players (control group). One group has started the teaching-learning-training process by using situational method (GST), while in the other group it was used traditional method (GTS). After 15 training sessions, there was an inversion, with the first group using the situational method and the traditional method being applied in the second group during additional 15 training sessions. Training session's categorization (STEFANELLO, 1999) was conducted in order to confirm the employment of the teaching method. To assess the procedural knowledge was used KORA test (MEMMERT, 2002) on the tactical parameter recognize spaces. For the measurement of declarative tactical knowledge it was utilized the Tactical Knowledge Test of Network Attack Situations (PAULA, 2000). Pre-test scores appointed the three groups to be in similar levels of declarative tactical knowledge, convergent procedural tactical knowledge (tactical intelligence) and divergent procedural tactical knowledge (tactical creativity). On the GST, by applying the situational method (referring to 15 initial sections), there was no significant difference on the tactical declarative knowledge, but there was on the procedure convergent and divergent. On the GTS, by using the traditional method none of the tactical knowledge developed. When making the inversion of learning method on the GST (30 sections on the sequence situational traditional) it was detected a significant improvement of both tactical procedure knowledge. However, this did not occur on the GTS on the traditional-situational sequence. These results suggest that training sequence referring to GST provided significant improvement on the players' tactical intelligence and creativity.

Relação entre o processo de ensino-aprendizagem-treinamento e o desenvolvimento do conhecimento tático no voleibol / Relationship between teaching-learning-training process and the development of tactical knowledge in volleyball

O objetivo desse estudo foi verificar em que medida o processo de ensino-aprendizagem-treinamento utilizado em uma equipe feminina de voleibol favoreceu o desenvolvimento do conhecimento tático declarativo das atletas. Doze jogadoras (idade média 13,9 ± 0,3 anos) pertencentes a um clube participaram da pesquisa. Para caracterizar o processo de ensino-aprendizagem-treinamento foram filmadas e posteriormente analisadas 17 sessões consecutivas de treinamento. Para verificar o desenvolvimento do conhecimento tático, utilizou-se o teste validado por PAULA (2001), sendo este aplicado no início e no final das sessões de treino registradas. Na análise das sessões de treino, as atividades relacionadas ao desenvolvimento da capacidade técnica ocuparam 57,5 por cento do tempo total de treinamento, enquanto que em 29,9 por cento do tempo foram desenvolvidas atividades com características de aperfeiçoamento tático. Para o conhecimento tático, não foi verificado aumento em nenhuma das variáveis medidas no teste. Esses resultados demonstraram que o treinador planificou suas sessões de forma a dedicar maior atenção ao componente técnico, sendo este contemplado especialmente através das atividades sem conexão com situações de jogo, como "fundamentos individuais" ou "combinação de fundamentos". A estrutura de treinamento utilizada parece não ter favorecido o aumento do nível de conhecimento tático declarativo no decorrer do período de treinamento avaliado.

The aim of this study was to verify the extent to which the teaching-learning-training process used in a female volleyball team promoted the development of the tactical knowledge. Twelve female players (13.9 ± 0.3 years) of a volleyball team participated in the study. To characterize the process of teaching-learning-training were video recorded and subsequently analyzed 17 consecutive sessions of technical-tactical training. The test validated by PAULA (2001) was used to verify the development of the declarative tactical knowledge and it was applied at the beginning and at the end of the registered training sessions. When analyzing the training sessions, activities related to the development of technical capacity occupied 57.5 percent of total time of training, while in 29.9 percent of total time was developed activities with tactical characteristics. There was no increase in any of the variables measured in the tactical knowledge test. The results demonstrated that the coach prepared training sessions dedicating more attention to the technical component, which is shown particularly through the activities without association with game situations, as "individual skills" and "skills combination". The training design used does not seem to have helped to increase the declarative tactical knowledge during the study period.