Avaliação dos parâmetros neuromusculares em adolescentes jogadores de futebol: efeitos da idade cronológica, da maturação esquelética e do tamanho corporal

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Desportos, Programa de Pós-Graduação em Educação Física, Florianópolis, 2015.Introdução. A força muscular e a capacidade de desenvolver força rápida são importantes componentes neuromusculares para o desempenho físico de adolescentes jogadores de futebol. Objetivo. Analisar a influência da idade cronológica, da maturação esquelética e do tamanho corporal sobre a produção de torque (isométrico, concêntrico e excêntrico), a taxa de desenvolvimento de torque e a taxa de ativação muscular em adolescentes jogadores de futebol. Método. A amostra incluiu 55 jogadores de futebol de dois grupos etários, sub-15 (14,00-14,99 anos; n=25) e sub-16 (15,00-15,99 anos; n=30). Cada jogador foi classificado como atrasado, normomaturo e adiantado na maturidade esquelética baseado na diferença entre a idade esquelética e a idade cronológica. Além disso, os jogadores foram alocados em três grupos de tamanho corporal baseado no próprio valor de massa corporal (MC): menor MC (MC MC percentil 66). O pico de torque isométrico (PTISO), concêntrico (PTCON), excêntrico (PTEXC) e a taxa de desenvolvimento de torque (TDT) dos extensores (E) e flexores (F) do joelho foram determinados no dinamômetro isocinético. A taxa de ativação muscular isométrica foi avaliada pela eletromiografia de superfície. As comparações entre os diferentes grupos foram realizadas utilizando a análise de variância (ANOVA) one-way e a análise de covariância (ANCOVA). O nível de significância de 5% foi considerado para todas as análises estatísticas. Resultados. O PTISO-E, PTISO-F, PTCON-E e PTEXC-E aumentaram significantemente com a idade cronológica, enquanto o PTCON-F e o PTEXC-F não foram diferentes entre os grupos etários. Os jogadores mais pesados tiveram maiores valores de PTISO-F, PTCON-E, PTEXC-E, PTCON-F e PTCON-E comparado aos jogadores com menor MC e MC intermediária. Entretanto, a maturação esquelética não exerceu nenhum efeito sobre a produção do torque, independentemente da ação muscular e do grupo muscular. Jogadores do sub-16 e com maior MC apresentaram maiores valores para a TDT dos extensores do joelho comparado aos jogadores sub-15 e com menor MC, respectivamente. Entretanto, a TDT dos extensores do joelho não variou entre os grupos de maturidade esquelética. Nenhuma diferença significante foi observada para a TDT dos flexores do joelho e taxa de ativação muscular isométrica entre os grupos etários, maturacionais e de tamanho corporal. Conclusão. O efeito da idade cronológica e do tamanho corporal sobre o torque muscular e a TDT em jogadores defutebol entre 14-15 anos parece ser dependente das ações e dos grupos musculares envolvido no movimento.Abstract : Introduction. Muscle strength and the ability to develop rapid strength are important neuromuscular components for physical performance of adolescent soccer players. Purpose. To analyze the influence of chronological age, skeletal maturation and body size on torque production (isometric, concentric and eccentric), rate of torque development and muscle activation rate in young soccer players. Method. The total sample included 55 soccer players of two age groups, under-15 (14,00-14,99 years; n=25) and under-16 (15,00-15,99 years; n=30). Each player was classified as late, average and early skeletally mature based on difference between skeletal and chronological ages. Furthermore, players were allocated in to three body size groups based on your own body mass (BM): lower BM (BM percentile 66). Peak torque during isometric (PTISO), concentric (PTCON) and eccentric (PTECC) muscular actions and rate of torque development (RTD) for the knee extensors (E) and flexors (F) were assessed by isokinetic dynamometry. Isometric muscle activation rate was determined by surface electromyography (EMG). Comparisons were made using one-way analysis of variance (ANOVA) and analysis of covariance (ANCOVA). An alpha level of 5% was set for all statistical analyses. Results. Under-16 players had higher values for PTISO-E, PTISO-F, PTCON-E and PTEXC-E compared to their younger peers, whereas no significant differences were observed for PTCON-F and PTEXC-F between age groups. Heavier players presented consistently higher values for PTISO-F, PTCON-E, PTEXC-E, PTCON-F and PTCON-E compared to players with lower and intermediate BM. However, skeletal maturation did not have any influence on torque production, regardless of muscle actions and groups. Under-16 and heavier players showed higher absolute RTD than the under-15 and lighter players during knee extension, respectively. In contrast, RTD during knee extension did not differ among players of contrasting skeletal maturity status. Chronological age, skeletal maturity and body size were not significant sources of variation for RTD during knee flexion and isometric muscle activation rate during both knee extension and flexion. Conclusion. The effect of chronological age and body size on torque production and RTD in soccer players aged 14-15 years seem be dependent on both muscle actions and groups involved in the movement

Reprodutibilidade e influência da maturacão biológica no desempenho do teste t-car em jogadores de futebol de 10 a 13 anos

TCC (Graduação) - Universidade Federal de Santa Catarina. Centro de Desportos. Curso de Graduação em Educação Física.A potência aeróbia máxima é considerada uma variável importante para o desempenho competitivo de jogadores de futebol. A escolha e seleção de testes válidos e fidedignos são recomendados para uma boa avaliação da potência aeróbia máxima. O teste T-CAR foi recentemente validado para predição da potência aeróbia máxima e o PV apresentou alta reprodutibilidade em jogadores adultos jovens (sub- 20). No entanto, na faixa etária de 10-13 anos ainda não foi investigada a reprodutibilidade, e sabe-se que o estado maturacional pode influenciar diretamente o desempenho em testes físicos, como o T-CAR. Portanto, o objetivo deste estudo foi verificar a reprodutibilidade do PV e FCmax determinado no T-CAR e a influência da maturação biológica sobre a performance de jogadores de futebol de 10 a 13 anos durante a realização do T-CAR. Participaram do estudo 37 adolescentes jogadores de futebol (12,5±1,1 anos, 43,4±11,1 kg, 152,2±10,8 cm, 16,68±4,60 % de gordura). Inicialmente os atletas realizaram o teste T-CAR para determinação do pico de velocidade (PV) e frequência cardíaca máxima (FCmax). O T-CAR possui multiestágios de 12s de corrida de ida e volta com pausas de 6s, velocidade inicial de 9,0 km.h-1 (incrementos de 0,6 km.h-1 a cada 90 segundos). Posteriormente, em outro dia, os atletas realizaram as avaliações de maturação sexual e esquelética no hospital para determinação dos estágios de Tanner e idade esquelética, respectivamente. Foi empregada a análise descritiva (média e desvio-padrão), seguido do teste de Shapiro- Wilk para verificar a normalidade dos dados. A análise de variância ANOVA oneway foi utilizada para comparar a diferença entre os valores de PV e as variáveis referentes à antropometria e maturação biológica dos atletas classificados nos diferentes estágios maturacionais esqueléticos, seguido do teste post-hoc de Tukey. Para verificar a reprodutibilidade do PV e FCmax foram utilizados o coeficiente de correlação intraclasse (CCI), erro típico de medida (ETM), coeficiente de variação do ETM (ETMCV). O PV obtido no T-CAR não apresentou diferenças significativas entre os grupos maturacionais (14,4±0,7 vs. 14,7±1,1 vs. 14,3±0,9 km.h-1, para o grupo atrasado, normal e adiantado, respectivamente). Além disso, não houve diferença significativa para os valores de PV (14,2±1,0 vs. 14,4±1,1 km.h-1; p>0,05) e FCmax (201±9 vs. 203±10 bpm; p>0,05) entre a situação de teste e reteste, assim como encontrou-se correlações alta e muito alta para os valores de FCmax (r=0.67) e PV (r=0.85) obtidos no T-CAR, respectivamente. Esses resultados destacam que o teste de campo T-CAR é reprodutível para avaliação da aptidão aeróbia de atletas de futebol no início da adolescência (10 a 13 anos) e que a performance no T-CAR não é influenciada pela maturação biológica, apresentando desta forma, implicações relevantes para detecção de jovens atletas talentosos

Training loads and RSA and aerobic performance changes during the preseason in youth soccer squads

The aims of this study were to compare the internal training load (ITL) in soccer players of two competitive age groups (under-15 [U-15] and under-19 [U-19]) during an 8-week preseason training period and compare the associated changes in physical performance measures. Eighteen U-15 and twelve U-19 players were monitored over an 8-week period during the preseason phase. The ITL was monitored using the session rating of perceived exertion (RPE) method. Before and after the preseason period, physical performance was assessed by best (RSA(best)) and mean (RSA(mean)) times in a repeated sprint ability (RSA) test and peak velocity derived from the Carminatti test (PVT-CAR). Total weekly ITL increased with age (U-15: 13770 +/- 874 AU vs. U-19: 33584 +/- 2506 AU; p < 0.001). In addition, U-19 players perceived training sessions as heavier than U-15 players (6.1 +/- 0.3 vs. 5.3 +/- 0.3 AU, respectively; p < 0.001). After the preseason period, very likely to almost certainly positive changes were observed for all performance measures in both age groups. However, the U-15 group had possibly superior gains in RSA(best) (+ 1.40%, 90% CL - 0.29 to 3.05, with ES = 0.35) and likely higher effects in RSA(mean) (+ 1.89%, 90% CL 0.04 to 3.70, with ES = 0.53) and PVT-CAR (+ 2.71%, 90% CL 0.35 to 5.01, with ES = 0.37) compared to the U-19 group. In conclusion, our findings demonstrate that the U-19 group accumulate higher total weekly ITLs than the U-15 group during the preseason phase due to longer and heavier training sessions. However, the U-15 group obtained superior gains in soccer-specific physical abilities while accumulating half the total ITLs during lighter training sessions

Effects of resisted vs. conventional sprint training on physical fitness in young elite tennis players

This study aimed to compare the effects of 6-week resisted sprint (RST) versus conventional (unresisted) sprint training (CG) on sprint time, change of direction (COD) speed, repeated sprint ability (RSA) and jump performance (countermovement jump (CMJ) and standing long jump (SLJ)) in male young tennis players. Twenty players (age: 16.5 +/- 0.3 years; body mass: 72.2 +/- 5.5 kg; body height: 180.6 +/- 4.6 cm) were randomly assigned to one of the two groups: RST (n = 10) and CG (n = 10). The training program was similar for both groups consisting of acceleration and deceleration exercises at short distances (3-4 m), and speed and agility drills. The RST group used weighted vests or elastic cords during the exercises. After 6 weeks of intervention, both training regimes resulted in small-to-moderate improvements in acceleration and sprint ability (5, 10, 20 m), SLJ and CMJ performances, COD pivoting on both, the non-dominant (moderate effect) and the dominant (small effect) foot, and the percentage of decrement (small effects) during a RSA test. Between-group comparisons showed that the SLJ (Delta = 2.0%) and 5 m sprint time (Delta = 1.1%) improved more in the RST group compared with the CG group. This study showed that 6 weeks of RST or unresisted training are time-efficient training regimes for physical improvements in young male tennis players

Different Pathways Leading up to the Same Futsal Competition: Individual and Inter-Team Variability in Loading Patterns and Preseason Training Adaptations

During the preseason, futsal players deal with large internal load, which may result in a reduction in physical performance. The aims of this study were to compare the session rating of perceived exertion training load (s-RPE TL) during the preseason between two teams; and to analyze the changes on the delayed-onset muscle soreness (DOMS), aerobic- and speed-power characteristics in players accumulating different s-RPE TL (Low (LTL) vs. High (HTL)). Twenty-eight players (Team A, n = 15; Team B, n = 13) were recruited. The s-RPE TL was monitored throughout the preseason phase (five weeks) in both teams. The coaches of each team planned the activities that comprised their training programs, without any interference from the researchers. Team A evaluated countermovement jumps (CMJ) and DOMS weekly. Team B performed squat jumps (SJ), CMJ, 5 m and 15 m sprints, and a futsal intermittent endurance test (PVFIET) before and after the preseason. Team B accumulated an almost-certainly greater s-RPE TL than Team A. In Team A, the CMJ height was likely to almost certainly improved for the HTL group from week 3. In Team B, the 5 m and 15 m sprint likely decreased after the preseason. Changes in 5 m (r = -0.61) and 15 m (r = -0.56) were correlated with total s-RPE TL. Changes in PVFIET were positively associated with changes in sprint, but inversely related to the baseline. s-RPE TL differed between both teams, and substantial gains in neuromuscular performance were observed for the HTL group in Team A. Slower and faster players in Team B showed distinct intermittent-endurance and speed adaptive responses during the high-volume preseason

Preocupações pedagógicas de estudantes-estagiários na formação inicial em Educação Física

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 the test Qui-quadrado (p < 0,05), present in the software SPSS 11.5. The results showed the higher scores of concern 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.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 dados foi a “escala de preocupações pedagógicas do professor” (MATOS et al., 1991). Na análise estatística utilizou-se o teste Qui-quadrado (p < 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-se que 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 etária até 23 anos demonstraram índices mais elevados de preocupação em todas as dimensões do que aqueles com faixa etária superior a 24 anos

Factors Associated with Emotion Regulation in Men with Internet Access Living in Brazil during the COVID-19 Pandemic

Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Objective: to evaluate the factors associated with emotion regulation in men with internet access living in Brazil during the COVID-19 pandemic. Method: an epidemiological survey, conducted with 1015 men. An electronic form was applied containing sociodemographic and occu-pational characteristics, support and coping strategies, as well as emotional and behavioral aspects. Emotion regulation was assessed using the Emotion Regulation Questionnaire. Results: The prevalence values observed were 44.6% for Low Cognitive Reappraisal and of 47.1% for High Emotional Sup-pression. The following factors were identified as associated: (a) with Low Cognitive Reappraisal: being aged 30 years old or more, practicing physical activity, worrying about social distancing and having positive emotions and feelings; and (b) with High Emotional Suppression: being heterosexual, non-white race/skin color, having security support or public administration, not sanitizing food, worrying about lack of physical activity and not having negative emotions. Conclusion: the adoption of emotion regulation strategies was associated with individual, contextual and emotional/behavioral characteristics. Masculinity ideals seem to exert an influence on these relationships.publishersversionpublishe

Genetics of Host Response to Leishmania tropica in Mice – Different Control of Skin Pathology, Chemokine Reaction, and Invasion into Spleen and Liver

Several hundred million people are exposed to the risk of leishmaniasis, a disease caused by intracellular protozoan parasites of several Leishmania species and transmitted by phlebotomine sand flies. In humans, L. tropica causes cutaneous form of leishmaniasis with painful and long-persisting lesions in the site of the insect bite, but the parasites can also penetrate to internal organs. The relationship between the host genes and development of the disease was demonstrated for numerous infectious diseases. However, the search for susceptibility genes in the human population could be a difficult task. In such cases, animal models may help to discover the role of different genes in interactions between the parasite and the host. Unfortunately, the literature contains only a few publications about the use of animals for L. tropica studies. Here, we report an animal model suitable for genetic, pathological and drug studies in L. tropica infection. We show how the host genotype influences different disease symptoms: skin lesions, parasite dissemination to the lymph nodes, spleen and liver, and increase of levels of chemokines CCL2, CCL3 and CCL5 in serum

Global transpiration data from sap flow measurements : the SAPFLUXNET database

Plant transpiration links physiological responses of vegetation to water supply and demand with hydrological, energy, and carbon budgets at the land-atmosphere interface. However, despite being the main land evaporative flux at the global scale, transpiration and its response to environmental drivers are currently not well constrained by observations. Here we introduce the first global compilation of whole-plant transpiration data from sap flow measurements (SAPFLUXNET, https://sapfluxnet.creaf.cat/, last access: 8 June 2021). We harmonized and quality-controlled individual datasets supplied by contributors worldwide in a semi-automatic data workflow implemented in the R programming language. Datasets include sub-daily time series of sap flow and hydrometeorological drivers for one or more growing seasons, as well as metadata on the stand characteristics, plant attributes, and technical details of the measurements. SAPFLUXNET contains 202 globally distributed datasets with sap flow time series for 2714 plants, mostly trees, of 174 species. SAPFLUXNET has a broad bioclimatic coverage, with woodland/shrubland and temperate forest biomes especially well represented (80 % of the datasets). The measurements cover a wide variety of stand structural characteristics and plant sizes. The datasets encompass the period between 1995 and 2018, with 50 % of the datasets being at least 3 years long. Accompanying radiation and vapour pressure deficit data are available for most of the datasets, while on-site soil water content is available for 56 % of the datasets. Many datasets contain data for species that make up 90 % or more of the total stand basal area, allowing the estimation of stand transpiration in diverse ecological settings. SAPFLUXNET adds to existing plant trait datasets, ecosystem flux networks, and remote sensing products to help increase our understanding of plant water use, plant responses to drought, and ecohydrological processes. SAPFLUXNET version 0.1.5 is freely available from the Zenodo repository (https://doi.org/10.5281/zenodo.3971689; Poyatos et al., 2020a). The "sapfluxnetr" R package - designed to access, visualize, and process SAPFLUXNET data - is available from CRAN.Peer reviewe