Resumo O objetivo do presente estudo foi analisar a associação entre o local de nascimento e idade relativa com a obtenção de medalhas olímpicas em atletas brasileiros. A amostra foi constituída por 186 atletas medalhistas olímpicos nascidos em território brasileiro. A análise dos dados realizou-se por meio da estatística descritiva (incidência e percentual) e inferencial (Qui-Quadrado a regressão logística binária). A associação entre os contingentes populacionais e campeões olímpicos apresentou resultado significativo (p<0,05), porém, não foram encontradas associações significativas com a idade relativa. Concluiu-se que a maioria dos atletas medalhistas olímpicos nasceu em locais que apresentam melhores condições de vida, com o IDHM médio que aparece apenas nas cidades com mais de 100 mil habitantes, além de a idade relativa não ser um critério importante na obtenção de medalhas dos atletas investigados.

Abstract The aim of the present study was to analyze the association between birthplace and relative age with winning Olympic medals in Brazilian athletes. he sample consisted of 186 Olympic medalist athletes born in Brazil. Data analysis was performed through descriptive (incidence and percentage) and inferential statistics (Chi-Square to binary logistic regression). The association between population contingents and Olympic champions presented a significant result (p <0.05); however, no significant associations were found with relative age. It was concluded that most Olympic medalists were born in places that present better living conditions, with intermediate MHDI, which appears only in cities with more than 100 thousand habitants, and relative age is not an important criterion in winning medals among athletes investigated.

RESUMO O presente estudo teve como objetivo analisar o desempenho anaeróbio e a ativação muscular durante um teste de ciclismo supramáximo em três diferentes alturas do selim. Doze ciclistas competitivos completaram um teste incremental em cicloergômetro e três testes de Wingate de 30 s em diferentes alturas do selim (referência, baixa e alta), de forma randomizada, em diferentes dias. A altura do selim foi alterada para baixo e para cima a partir da posição de referência usando como parâmetro o valor referente a (± 2,5%) da distância da sínfise púbica até o solo. O sinal eletromiográfico (EMG) foi obtido dos músculos reto femoral, vasto lateral, bíceps femoral (cabeça longa) e gastrocnêmio lateral. As variáveis anaeróbias e os dados de EMG foram divididos em seis janelas consecutivas de 5 s. Os sinals EMG foram normalizados pela primeira janela da posição de referência para estipular as mudanças percentuais ao longo do teste. Os resultados sugerem que durante o teste de Wingate de 30 s pequenas alterações na altura do selim resultam em aumento da potência pico (referência=1380±241 W; baixa=1497±175 W, p=0,036; alta=1491±225 W, p=0,049) e maior período de ativação percentual para o vasto lateral (referência=33,6%, baixa=33,2%, alta=35,0%; p=0,001) em relação ao reto femoral (referência=24,5%, baixa=25,2%, alta=23.7%), bíceps femoral (referência=20,7%, baixa=20,8%, alta=19,9%) e gastrocnêmio lateral (referência=21,2%, baixa=20,8%, alta=19,9%). Os resultados sugerem que pequenos ajustes na altura do selim podem afetar a relação força-comprimento e, consequentemente, a capacidade de gerar força e o padrão de recrutamento muscular dos membros inferiores.

ABSTRACT This study aimed to analyze the anaerobic performance and muscle activation during a supramaximal cycling test at three different saddle positions. Twelve competitive cyclists completed an incremental cycling test and three 30-s Wingate tests in three different saddle heights (reference, downward, and upward), in a random order, on different days. The saddle height was individually shifted downward and upward (seeing 2.5% of the distance from the pubic symphysis to ground) from the reference position. The electromyographic signal (EMG) data was obtained from the rectus femoris, vastus lateralis, biceps femoris (long head), and gastrocnemius lateralis in order to assess muscle activation during the entire test. The anaerobic variables and the EMG data were divided into six consecutive windows of 5-s. The EMG signals were normalized by the first 5-s window of the reference position to provide the percentage changes throughout the test. The results suggest that during a 30-s Wingate test small changes in saddle height result in greater peak power output (reference=1380±241 W; downward=1497±175 W, p=0.036; upward=1491±225 W, p=0.049) and greater activation period for vastus lateralis (reference=33.6%, downward=33.2%, upward=35.0%; p=0.001) in comparision to rectus femoris (reference=24.5%, downward=25.2%, upward=23.7%), biceps femoris (reference=20.7%, downward=20.8%, upward=19.9%), and gastrocnemius lateralis (reference=21.2%, downward=20.8%, upward=19.9%). The results suggest that small adjustments in saddle height may affect the force-length relationship of the muscles of the lower limb, and consequently their recruitment pattern and their ability to generate force.

The aim of this study was to analyze the effect of different squat depths in the performance and biomechanical parameters at counter movement jump (CMJ). Twenty-two male volleyball or basketball players volunteered to participate in this study and all were currently competing at the college level. The CMJ was performed in three different conditions: 1) with relative knee flexion at the end of counter movement phase smaller than 90° (<90°); 2) greater than 90° (>90°), and; 3) preferred position (PREF). During the CMJ, kinematic, kinetic, and electromyography parameters were assessed. ANOVA for repeated measures with post-hoc Bonferroni´s test was used for variables comparison, with a significance level set at p≤0.05. The higher performance was on PREF and <90° situations compared with CMJ>90°. Average and peak power, as well as absolute and normalized peak forces, were higher in >90° CMJ. The peak velocity of CG and angular velocities of hip and knee were higher in the <90° condition. EMG activity of the vastus lateralis (VL) during the descending and ascending phases were higher in position >90°. Recuts femoris and biceps femoris did not show difference in any jump phases. In conclusion, the knee flexion interferes the performance and the biomechanical variables at the CMJ. The highest jumps were got at a deeper squat, so this technique could be used for athletes in order to optimize the vertical jump performance in the training and competitions.