Modelling anaerobic peak power assessed by the force-velocity test among late adolescents

SUMMARY OBJECTIVES: The aim of this study was to examine the concurrent contributions of body size, estimates of whole-body composition, and appendicular volume in addition to participation in competitive basketball to explain inter-individual variance in anaerobic peak power output during late adolescence. The study also tested non-participation versus participation in basketball as an independent predictor of peak power output. METHODS: The sample of this cross-sectional study was composed of 63 male participants (basketball: n=32, 17.0±0.9 years; school: n=31, 17.4±1.0 years). Anthropometry included stature, body mass, circumferences, lengths, and skinfolds. Fat-free mass was estimated from skinfolds and lower limbs volume predicted from circumferences and lengths. Participants completed the force-velocity test using a cycle ergometer to determine peak power output. RESULTS: For the total sample, optimal peak power was correlated to body size (body mass: r=0.634; fat-free mass: r=0.719, lower limbs volume: r=0.577). The best model was given by fat-free mass and explained 51% of the inter-individual variance in force-velocity test. The preceding was independent of participating in sports (i.e., the dummy variable basketball vs. school did not add significant explained variance). CONCLUSION: Adolescent basketball players were taller and heavier than school boys. The groups also differed in fat-free mass (school: 53.8±4.8 kg; basketball: 60.4±6.7 kg), which was the most prominent predictor of inter-individual variance in peak power output. Briefly, compared to school boys, participation in basketball was not associated with optimal differential braking force. Higher values in peak power output for basketball players were explained by a larger amount of fat-free mass.

Tactical rule and pitch size change the physical and technical performance of young soccer players during small-sided games / A regra tática e o formato do campo mudam o desempenho físico e técnico de jovens jogadores de futebol durante jogos reduzidos

Abstract The present study examined the effects of small-sided and conditioned games (SSCGs) manipulating tactical rules (ball-possession [BP] vs goal-scoring with goalkeepers [GS]) and pitch size (square [SP] vs rectangular [RP]) on the running performance and technical skills of young soccer players. Ten male soccer players (chronological age: 12.45 ± 0.51 years; body mass: 41.99 ± 7.97 kg; height: 152.85 ± 10.03 cm) were monitored using GPS units during SSCG formats. The distance covered at different running intensities and number of technical actions were used in analyses. SSCG-induced changes in 30 m sprint and CMJ performances were also evaluated. Compared to BP, GS elicited significantly lower distances covered at low intensity running (p=0.003; d=-0.95), more sprints (p=0.050; d=0.67), and longer distances covered in terms of walking (p=0.035; d=2.60) and sprinting (p=0.029; d=0.75); (ii) number of passes (short [p=0.002; d=1.10] and long [p=0.013; d=0.82]) were more frequent during BP than GS games, while RP game format allowed for greater occurrence of long passes (p=0.036; d=0.64) than under the SP condition; (iii) jumping and sprinting performance did not change (p>0.05) using different SSCG formats. In conclusion, GS games demand more sprint running episodes in terms of number and distance covered than BP games. In addition, RP game formats can be used to increase the occurrence of longer passes in young soccer players aged 11-13 years.

Resumo O estudo examinou os efeitos de diferentes jogos reduzidos e condicionados (JRC): manipulando as regras táticas (posse de bola (BP) vs. marcar gols com goleiro (GS)) e o formato do campo (quadrado vs. retangular) sobre o desempenho físico e técnico em jovens jogadores de futebol. Dez jogadores do sexo masculino (idade: 12,45 ± 0,51 anos; massa corporal: 41,99 ± 7,97 kg; altura: 152,85 ± 10,3 cm) foram monitorados através do sistema de posicionamento global e os JRC gravados em vídeo. A distância percorrida em diferentes intensidades e o número de ações técnicas para os 4 diferentes JRC foram usadas para análise. O efeito dos JRC sobre o desempenho no teste de sprints de 30 m e altura do salto vertical também foram analisadas. Os JRC para GS provocaram distâncias significativamente menores em corrida de baixa intensidade (p=0.003; d=-0.95) e mais sprints (p=0.050; d=0.67) e maiores distâncias caminhando (p=0.035; d=2.60) e em sprint (p=0.029; d=0.75) comparado ao BP; (ii) o número de passes (curtos [p=0.002; d=1.10] e longos [p=0.013; d=0.82]) é maior nos JRC de BP que GS. O formato retangular permite maior ocorrência de passes longos que o modelo quadrado (p=0.036; d=0.64); (iii) o desempenho de salto vertical e velocidade não mudou (p>0.05) após os JRC. Concluindo, ações envolvendo sprints em número e distância são maiores no JRC com GS comparado ao BP, enquanto que JRC de BP favorecem o desenvolvimento do passe. Por fim, o campo retangular com BP estimula a realização de passes mais longos em jovens jogadores.

Performance comparison in the Wingate test between standing and seated positions in competitive cyclists

Abstract Aims: The current study aimed to compare the anaerobic power output through the Wingate test in different positions, i.e., standing and seated, and identify the relationship between power-output and body mass. Methods: Eleven male competitive cyclists (age: 30.3 ± 4.7 years; body mass: 73.7 ± 7.7 kg; body fat: 11.3 ± 4.2%) were submitted to two sessions of the Wingate test (WT) in different positions, on different days. Results: The peak power (W), average power (W), relative peak power (W·kg-1), relative average power (W·kg-1), average cadence (rpm), and average velocity (km·h-1) presented significant differences in the standing position compared with the seated position (p < 0.05), 1155 ± 130 vs. 1082 ± 182 (W), 875 ± 96 vs. 818 ± 116 (W), 15.9 ± 1 vs. 15.0 ± 2 (W kg-1), 12.1 ± 1 vs. 11.3 ± 1 (W kg-1), 117.5 ± 7 vs. 109.8 ± 10 (rpm), 37.0 ± 2 vs. 34.6 ± 3 (km·h-1), respectively. However, when controlled the body mass, the differences in variables power output ceased to exist (p > 0.05). The fatigue and peak heart rate (bpm) indices did not present significant differences between the tests (p > 0.05). Conclusions: Sprint performance was improved when the WT was performed in a standing position in competitive cyclists. The study also reports the important relationship between body mass and anaerobic production capacity in the WT, emphasizing that it is desirable an increase in lean body mass and a reduction in fat mass, similar in competitions. We suggest that, for anaerobic assessment in cyclists, the standing position should be used during the WT, to determine the maximum power-output capacity.

Comparison of maturation and physical performance in basketball athletes of different playing positions / Comparação da maturação e desempenho físico em atletas de basquetebol de diferentes posições de jogo

Abstract The aim of this study was to compare the characteristics of somatic maturation, anthropometric and physical performance (vertical jump and aerobic power) in young basketball players of different playing positions (under 13 years) and analyze these relationships using Peak Height Velocity (PHV) as a measure of somatic maturation. For this, 26 male athletes were evaluated. Anthropometric variables were: body mass, standing and sitting height, and length of lower limbs. Maturation was determined by age at PHV. Physical performance was determined by lower limb power (counter movement jump - CMJ) and aerobic power (Intermittent Recovery Test) tests. MANOVA reported significant differences (p<0.05) among playing positions regarding variables Maturity Offset, estimated PHV age, standing height, sitting height, estimated leg length, body mass and Yo-Yo IR1. In addition, it was identified that point guards reached estimated PHV at later age than their peers who act as small forwards and centers. Regarding CMJ, no significant differences were identified among playing positions, but in relation to aerobic power, point guards and small forwards presented higher performance. These findings confirm that maturation has great effect on growth and physical performance measures and the estimated PHV age is an applicable tool in young athletes, mainly aiding professionals in structuring the teaching-learning- training process in this age group.

Resumo O objetivo do presente estudo foi comparar as características de maturação somática, antropométricas e desempenho físico entre as posições de jogo em jogadores de Basquetebol sub-13 e analisar estas relações utilizando o Pico de Velocidade de Crescimento (PVC) como uma medida da maturação somática. Para tanto, 26 atletas do sexo masculino foram avaliados. As variáveis antropométricas foram: massa corporal, estatura em pé e sentado e comprimento de membros inferiores. A maturação foi determinada pela idade do PVC. O desempenho físico foi através dos testes de potência de membros inferiores (salto com contra movimento - CMJ) e potência aeróbia (Yo-Yo IR1). A MANOVA reportou diferenças significativas (p<0,05) entre as posições em quadra nas variáveis Maturity Offset, idade do PVC estimado, estatura, altura sentado, comprimento de pernas estimado (CPE), massa corporal e Yo-Yo IR1. Além disso, foi identificado que os armadores alcançaram o PVC estimado, em uma idade mais tarde que seus companheiros que atuam como alas e pivôs. Em relação ao CMJ não foram identificadas diferenças significativas entre as posições, já em relação a potência aeróbia, os armadores e alas apresentaram desempenho significativo superior quando comparados aos pivôs. Estes achados confirmam que a maturação tem um grande efeito nas medidas de crescimento e desempenho físico e a determinação da idade estimada do PVC apresenta-se como uma ferramenta aplicável em jovens atletas, principalmente no auxílio de profissionais na estruturação do processo de ensino-aprendizagem-treinamento nesta faixa etária.

Relative age effect, skeletal maturation and aerobic running performance in youth soccer players

To investigate the presence of a relative age effect (RAE) and the influence of birth quarters (BQ), semesters (S) as well as skeletal maturation on anthropometric characteristics and aerobic peak speed (PST-CAR) in youth male soccer players. Methods: One hundred players were recruited to participate in this study. Players were allocated into 4 BQ's and 2 S. Skeletal maturity status was assessed using the Fels method. Assessments for players included determination of body size and composition and PST-CAR. Results: Overall, more players were born in BQ1 (38 %) and S1 (75%). The likelihood of players born in BQ1 and BQ2 being selected was 3.61 to 4.96 times higher than players in BQ3 and BQ4. Players in BQ4 maturing earlier were biologically older than their peers in BQ1. The players in BQ3 and S2 displayed higher PST-CAR compared with players in BQ2 and S1, respectively. However, players of contrasting skeletal maturity status did not differ in aerobic performance. Conclusion: Our findings indicate that coaches and talent scouts are systematically retaining average and early maturing players born in S1 and excluding late maturing players born in BQ4. However, aerobic performance appeared to be dependent on the relative age, but independent of skeletal maturation during puberty.(AU)

TESTE DE CARMINATTI: ANÁLISE DA REPRODUTIBILIDADE EM JOVENS MILITARES / CARMINATTI'S TEST: RELIABILITY ANALYSIS IN YOUNG MILITARY

RESUMOO objetivo do presente estudo foi analisar a reprodutibilidade relativa e absoluta do pico de velocidade (PVT-CAR) e da frequência cardíaca máxima (FCmáx) determinados no teste incremental de Carminatti (T-CAR) em jovens militares. Vinte e sete militares do sexo masculino (idade = 19,3±1,1 anos, massa corporal = 69,5±7,7 kg, estatura = 1,76±0,9m, percentual de gordura = 8,9±3,2 %) pertencentes à Marinha do Brasil foram recrutados para participar deste estudo. Os participantes foram submetidos a duas sessões de avaliação, separadas por 48 horas, para a determinação do PVT-CAR e FCmáx a partir do protocolo do T-CAR. Os testes foram realizados nomes no horário, como intuito de minimizar a interferência das variações biológicas. Não foi encontrada diferença significativa para o PVT-CAR (t=0,773; p=0,446) e FCmax (t=0,543; p=0,592) entre a situação de teste e reteste. Além disso, o coeficiente de correlação intraclasse (CCI) do PVT-CARe FCmax foram 0,73 e 0,90, com um coeficiente de variação do erro típico de medida (CVETM) de 1,55% e 1,28%, respectivamente. As análises de Bland-Altman para o PVT-CAR e FCmax também sugerem que houve boa concordância para essas medidas em condições repetidas. Desta forma, os resultados do presente estudo mostram que houve uma baixa variação intra-individual para o PVT-CARe FCmax, resultando em evidências consistentes de reprodutibilidade absoluta (CVETM) erelativa (CCI). Como aplicação prática,o T-CAR parece ser uma estratégia interessante para avaliar a máxima velocidade aeróbia de jovens militares em diferentes momentos do planejamento anual de treinamento.

ABSTRACTThe purpose of this study was to analyse the relative and absolute reliability of peak velocity (PV) and heart rate maximum (HRmax) derived from Carminatti's incremental test (T-CAR) in young military. Twenty-seven healthy male (age = 19.3 ± 1.1 years, body mass = 69.5 ± 7.7 kg, height = 1.76 ± 0.9 m, body fat percentage = 8.9 ± 3.2 %) belonging to Brazil's Navy were recruited to participate in the current study. Participants performed two assessment sessions, separated by 48 h, to determine the PVT-CAR and HRmax from the T-CAR protocol. The tests were performed on the same day time, in order to minimize the interference of biological variations. There was no significant differences for PVT-CAR (t=0.773; p=0.446) and HRmax (t=0.543; p=0.592) between the test-retest situation. The intraclass correlation coefficient (ICC) for PVT-CAR and HRmax were 0.73 and 0.90, with a coefficient of variation of the typical error of measurement (CVTETM) of 1.55% and 1.28%, respectively. In addition, Bland-Altman plots for PVT-CAR and HRmax suggest that there was acceptable agreement for these measures in repeated conditions. In conclusion, our finding show that there was a low intra-individual variation for PVT-CAR and HRmax, resulting in consistent evidence of absolute (CVETM) and relative (ICC) reliability. As a practical application, the T-CAR test seems to be an interesting alternative to evaluate the maximal aerobic speed of young military at different moments of the annual training planning.

Perfil antropométrico e performance aeróbia e anaeróbia em jovens jogadores de futebol / Anthropometric profile and aerobic and anaerobic performance in young soccer players

O objetivo do presente estudo foi comparar as características antropométricas e performance aeróbia e anaeróbia de adolescentes jogadores de futebol. Para tanto, participaram deste estudo 34 jogadores da categoria infantil (INF) (idade 14,44 ± 0,55 anos, massa corporal 60,94 ± 8,51 kg, estatura 173,16 ± 8,91 cm) e 30 jogadores da categoria juvenil (JUV) (idade: 15,94 ± 0,69 anos, massa corporal 70,0 ± 9,86 kg, estatura 177,58 ± 8,24 cm).Todos os adolescentes foram submetidos a medidas antropométricas, composição corporal e somatotipo, seguido pelos seguintes protocolos de campo: teste de Carminatti (T-CAR) para avaliação da potência aeróbia máxima a partir da determinação do pico de velocidade (PV), teste anaeróbio de sprints repetidos e teste de velocidade de 10 e 30 m. Para detectar possíveis diferenças entre as categorias competitivas foi utilizado o teste t de Student para amostras independentes adotando o nível de significância de 5%. Os jogadores JUV foram mais pesados, mais altos e apresentaram maiores perímetros musculares comparado aos jogadores INF, enquanto para o somatório das dobras cutâneas não foram visualizadas diferenças. Os desempenhos nos testes aeróbios e anaeróbios analisados foram significativamente superiores para a categoria juvenil em relação à infantil. Dessa forma, podemos concluir que a idade cronológica determina as diferenças nas características antropométricas e nos desempenhos físico de jovens jogadores no meio (categoria infantil) e final (categoria juvenil) da adolescência como provável resultado do processo de crescimento e maturação biológica.

The aim of this study was to compare anthropometric characteristics and aerobic and anaerobic performance of adolescent soccer players. For this, young soccer players classified asunder 15 - U15 (n=34; age 14.44 ± 0.55 years, body mass 60,94 ± 8,51 kg, stature 173,16 ± 8,91 cm) and under 17 - U17 (n=30; age 15.94 ± 0.69 years, body mass 70,0 ± 9,86 kg, stature 177,58 ± 8,24 cm) participated in this study. All adolescents were submitted to performed anthropometric assessments, body composition andsomatotype, accompanied by the following field tests protocols: Carminatti test (T-CAR) for the evaluation of maximal aerobic power from the determination of the peak velocity (PV), repeated sprints anaerobic test (40 m RSA) and the 10 m and 30 m speed test. To detect possible differences between competitive age groups (U-17 vs. U-15) was used t test for independent samples adopting significance level of 5%. Older players (U-17) were heavier, taller and had greater muscle circumferences compared to youngest players belonging U-15 age group, while for the sum of skinfolds were not visualized differences among them. Thus, we can conclude that chronological age determines differences in morphological characteristics and motor performances (aerobic and anaerobic indicators) of young soccer players in middle (U-15) and end (U-17) of adolescence period as probable outcome of biological growth and development.

Resposta cardiorrespiratoria e gasto energetico em exercicio na maxima fase estavel de lactato / Cardiorespiratory response and energy expenditure during exercise at maximal lactate steady state

A resposta cardiorrespiratória durante exercícios submáximos, na intensidade da máxima fase estável de lactato (MFELint) até a exaustão, tem sido pouco investigada. O objetivo deste estudo foi investigar a resposta do consumo de oxigênio (VO2), frequência cardíaca (FC) e pulso de oxigênio (pulso O2) em exercício realizado na MFELint até a exaustão, e comparar o gasto energético (GE) estimado pelo VO2 e pela FC. Doze sujeitos treinados realizaram um protocolo incremental em cicloergômetro para determinar parâmetros máximos e submáximos do metabolismo aeróbio. Posteriormente, foram realizados 2 a 4 testes de 30 min com carga constante para identificar a MFELint. Finalmente, os sujeitos realizaram um teste até a exaustão na MFELint. Os parâmetros cardiorrespiratórios foram medidos continuamente durante todos os testes. No teste de exaustão, as respostas fisiológicas foram comparadas entre seis momentos relativos do tempo de exaustão (TTE). O TTE médio foi 55,1±10,2 min. O pulso de O2 apresentou reduções significativas ao longo do tempo, atingindo, no momento da exaustão, um valor ~ 9% inferior comparado ao início do exercício. Este fato ocorreu pelo aumento da FC ao longo do tempo de forma desproporcional ao aumento do VO2, resultando em diferenças significantes entre os GE estimados. Portanto, em exercício realizado na MFELint até a exaustão, parece existir uma perda gradual da eficiência cardiorrespiratória, evidenciada pela redução do pulso O2. Assim, a relação direta entre VO2 e FC com a carga de trabalho é alterada ao longo do exercício, conduzindo a erros de estimativa do GE a partir dos valores da FC.

There has been little research regarding cardiorespiratory responses during submaximal exercise at the maximal lactate steady state intensity (MLSSint) until exhaustion. The objective of this study was to investigate the responses of oxygen consumption (VO2), heart rate (HR) and oxygen pulse (O2 pulse) during exercise to exhaustion at MLSSint, and to compare energy expenditure (EE) estimated by VO2 and HR. Twelve trained athletes followed an incremental protocol on a cycle ergometer to determine maximal and submaximal parameters of aerobic metabolism. On subsequent occasions they performed 2 to 4 30-minute tests with constant load to identify MLSSint. Finally, they underwent a test to exhaustion at MLSSint. Cardiorespiratory parameters were measured continuously during all tests. During the test to exhaustion, physiological responses were compared for six points in time calculated as percentages of the time to exhaustion (TTE). Mean TTE was 55.1±10.2 min. Oxygen pulse presented significant reduction over time, decreasing to a value 9% lower than baseline at the exhaustion point. This fact was the result of increases in HR over time that was disproportional to the increase in VO2, resulting in significant differences between EE estimates. Therefore, there appears to be a gradual loss of cardiorespiratory efficiency during exercise to exhaustion at MLSSint that is shown by the reduction in O2 pulse. The direct relationship between VO2 and HR with workload presents variations over the course of exercise, leading to errors when EE is estimated using HR.

Preocupações pedagógicas de estudantes-estagiários na formação inicial em Educação Física / Pedagogic concerns of students-trainees in initial formation in Physical Education

O objetivo dessa investigação foi analisar as preocupações pedagógicas de estudantes estagiários na formação inicial em Educação Física. Participaram do estudo 106 estudantes-estagiários do curso de Educação Física de duas universidades da região Sul do Brasil. O instrumento de coleta de dadosfoi a escala de preocupações pedagógicas do professor (MATOS et al., 1991). Na análise estatísticautilizou-se o teste Qui-quadrado (p menor que 0,05), contido no software SPSS 11.5. Os resultados destacaram escores mais elevados de preocupação com o impacto e escores mais baixos de preocupação com a tarefa. Apesar de não serem encontradas associações na entre as variáveis investigadas, constatou-seque o grupo feminino apresentou níveis mais elevados de preocupação nas dimensões consigo próprio,com a tarefa e com o impacto do que o grupo masculino. Da mesma forma, os estagiários na faixa etáriaaté 23 anos demonstraram índices mais elevados de preocupação em todas as dimensões do que aquelescom faixa etária superior a 24 anos.

This investigation aimed to analyze the pedagogic concerns of students-trainees in initial formation in Physical Education. 106 students-trainees of the graduation in Physical Education had participated in the research, from two universities in the South region of Brazil. The data collect tool was the scale of pedagogic concerns of the teacher (MATOS et al., 1991). In the statistic analysis it was used thetest Qui-quadrado (p smaller that 0,05), present in the software SPSS 11.5. The results showed the higher scores ofconcern with the impact, and lower scores of concern with students-trainees activity. Although not being found associations among the investigated variables, it was verified that the female group presented higher levels of preoccupation in relation to itself dimensions, with the task and impact than the male group. Likewise, the trainees in the 23 age range demonstrated higher indexes of preoccupation in all dimensions than the ones in the age rate superior to 24 years old.