Existe associação entre nível de atividade física e composição corporal em adolescentes? / Is there an association between level physical activity and body composition of adolescents?

Os objetivos do presente estudo foram (i) testar se existe associação e (ii) diferença entre o nível de atividade física (NAF) e composição corporal de adolescentes de escolas públicas e p riv adas. Participaram do presente estudo 84 adolescentes (feminino: n = 52; 61,9% e masculino: n = 3 2 ; 3 8 ,1 %) com idade média de 16,4 ± 0,8 anos (feminino = 16,5±0,8 anos e masculino 16,4 ± 0,8 anos) regularmente matriculados em uma escola pública e uma privada do município de Fortaleza/CE. O NAF foi quantificado por meio da aplicação do o questionário de atividade física para adolescentes. Posteriormente foram obtidos dados (massa corporal e estatura) para cálculo do índice de massa corporal (IMC). O percentual de gordura (%G) foi estimado de acordo com o sexo. O teste de correlação de Pea rso n foi utilizado para verificar associação entre as variáveis. Para comparação entre estudantes de escolas públicas e privadas, utilizamos as diferenças de médias estandardizadas, intervalo de co n fiança (90 %), tamanho do efeito e probabilidades de haver diferenças. Não encontramos associações significantes en tre o NAF e IMC (r = 0,033 à 0,214; p > 0,05) e NAF e %G (r = - 0,199 à 0,310; p > 0,05). Não h ouv eram diferenças substanciais entre estudantes de escolas pública e privada para NAF e variáveis de composição corporal. A falta de associação forte entre NAF e composição corporal aponta para o caráter multifatorial que perpassa a relação entre essas duas variáveis na população jovem. Adicionalmente, estudar em escola pública ou privada parece não afetar o NAF e a composição corporal de adolescentes...(AU)

The objectives of present study were (i) to test if there is an association and (ii) differen ce between the level of physical activity (LPA) and body composition of adolescents from public and private schools. A total of 84 adolescents (female: n = 52, 61.9% and males: n = 32, 38.1%), with a mean age o f .4 ± 0.8 years (female = 16.5 ± 0, 8 years and male 16.4 ± 0.8 years) regularly enrolled in a public an d private school in the municipality of Fortaleza/CE. NAF was quantified through the ap p lication o f t he physical activity questionnaire for adolescents. Subsequently data were obtained (body mass and height) to calculate the body mass index (BMI). The percentage of body fat (% BF) was estimated according to sex . The Pearson correlation test was used to verify association between the variables. For comparison between public and private school students, we used the differences of standardized means, co nfiden ce in terv al (90%), effect size and probability of differences. We did not find significant associations bet ween LPA and BMI (r = 0.033 to 0.214; p> 0.05) and LPA and % BF (r = - 0.19 to 0.310; p> 0.05). There were n o substantial differences between public and private school students for LPA and body co mpo sition. The lack of strong association between NAF and body composition points to the multifactorial character t hat per passes the relationship between these two variables in the young population. Additionally, studying in a public or private school does not seem to affect LPA and the body composition of adolescents...(AU)

The acute hypotensive effect of resistance training performed with machines vs free weights in normotensive men

Abstract AIMS To analyze if different resistance training (machine vs free weight) would have different acute hypotensive effect in active and normotensive individuals. METHODS Fifteen male volunteers (39.2±2.5 years) performed two different resistance exercise protocols, one on machinery and one with free weights for the similar muscle groups and volume (sets x repetitions). Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured at rest and during 60 minutes after the sessions. RESULTS There was no interaction between (treatments vs time) for SBP (F 70, 84 = 0.9445, p = 0.595) and DBP (F 70, 84 = 0.5743, p = 0.991). However, significant differences for time for SBP (F 14, 84 = 7.058, p = 0.001) and DBP (F 14, 84 = 3.296, p = 0.001), and treatment for SBP (F 5, 6 = 291.1, p = 0.001) and DBP (F 5, 6 = 13.29, p = 0.003) were varified. CONCLUSION Our findings indicate that both resistance training (machine or free weight) induce a similar hypotensive response for SBP in normotensive men.

Specific warm-up exercise is the best for vertical countermovement jump in young volleyball players

Abstract We evaluated the effect of performing various distinct warm-up exercises on vertical countermovement jump (VCMJ) performance. Eight volleyball players (age 15.4 ± 0.5 yrs) performed five different warm-up activities (in a counterbalanced, randomized crossover study) over five days, at 24-h intervals: stretching (4 × 30 s, 30 s between sets), cycloergometer (5 min at 50 W + 5 min at 100 W), resistance exercise (leg press 45°, 3 × 5 repetitions maximum, 3-min pause between sets), specific vertical jumping (4 × 10 VCMJ, 2-min pause between sets), and no warm-up at all (control condition). Beginning 3 min after their warm-up, the players performed 3 attempts (at intervals of 3 min) of VCMJ (on a contact carpet), and each player's best jump was considered in the analysis. All warm-up activities presented higher VCMJ performance (p< 0.05) than the control condition, with the exception of stretching. Vertical jumping revealed a large effect size(0.8) than other interventions. We conclude that in practical terms, vertical jumps are the best warm-up exercise (when applied by itself) to acutely improve VCMJ performance in volleyball players, but that other exercises can make a complementary contribution.

Perfil antropométrico e características físicas da equipe brasileira de futebol para amputados / Perfil antropométrico y características físicas del equipo brasileño de fútbol para amputados / Anthropometric profile and physical performance characteristic of the Brazilian amputee football (soccer) team

Amputee football is a variation of conventional soccer in which athletes with lower limb amputation and one athelete with upper limb amputation (the goalkeeper) participate. The objective of this study was to investigate the anthropometric and physical characteristics of amputee football athletes and to verify differences between heart rate peak (HRpeak) and equations for predicting maximum heart rate (HRmax). Twelve amputee soccer players from the Brazilian team participated in this study. The body mass, height and body composition were measured. The physical tests used were: the 20 m running test, the T-square test and the Yo Yo intermitent recovery test - level 1 (YYIRT1). The percentage of fat was significantly different between midfielders and defenders. No significant differences were found between positions in the physical tests. The HRpeak was significantly lower than all of HRmax prediction equations tested. We conclude that the indicators of physical performance did not differ significantly between the different tactics roles of players, and that, after intermittent maximum effort, the cardiac response was lower when compared with the investigated HRmax prediction equations.

O futebol de amputados é uma variação do futebol convencional, onde participam atletas amputados de membros inferiores e membros superiores (goleiro). O objetivo do estudo foi investigar as características físicas e antropométricas de atletas de futebol para amputados e verificar se existem diferenças entre a frequência cardíaca de pico (FCpico) e equações de predição da frequência cardíaca máxima (FCmax). Doze jogadores de futebol para amputados da seleção brasileira participaram do estudo. Foi mensurada a massa corporal, estatura e composição corporal. Os testes físicos utilizados foram: corrida de 20 m, teste do quadrado e o Yo Yo intermitent recovery test - level 1 (YYIRT1). O percentual de gordura foi significativamente diferente entre os meio-campistas e defensores. Não foram encontradas diferenças significativas entre as posições nos testes físicos. A FCpico foi significativamente menor do que todas as equações de predição da FCmax testadas. Conclui-se que os indicadores de desempenho físico não diferenciaram significativamente entre as diferentes funções táticas dos jogadores, e que a resposta cardíaca após esforço máximo intermitente é menor quando comparada com as equações de predição da FCmax investigadas.

El fútbol de amputados es una variante del fútbol convencional, en el cual participan atletas amputados de miembros inferiores y miembros superiores (portero). El objetivo del estudio fue investigar las características físicas y antropométricas de atletas de fútbol para amputados y verificar si hay diferencias entre frecuencia cardíaca pico (FCpico) y ecuaciones de predicción de frecuencia cardíaca máxima (FCmax). Doce jugadores de fútbol para amputados del equipo oficial brasileño participaron del estudio. Fue mensurada la masa corporal, estatura y composición corporal. Los testes físicos utilizados fueron: carrera de 20 m, test del cuadrado y Yo Yo intermitent recovery test - level 1 (YYIRT1). El porcentual de grasa fue significativamente diferente entre los mediocampistas y defensores. No fueron identificadas diferencias significativas entre las posiciones en los testes físicos. FCpico fue significativamente menor que todas las ecuaciones de predicción de FCmax evaluadas. Concluí-se que los indicadores de desempeño físico no diferenciaron significativamente entre las diferentes funciones tácticas de los jugadores y que la respuesta cardíaca tras el esfuerzo máximo intermitente es menor si comparadas con las ecuaciones de predicción de FCmax investigados.