Introdução: A coordenação motora é fundamental para o desenvolvimento motor e aprendizado de movimentos básicos, especialmente em crianças e jovens na iniciação esportiva. Entre os instrumentos de avaliação, destaca-se o Körperkoordinationstest für Kinder (KTK), amplamente utilizado por sua eficácia na mensuração de habilidades motoras e acompanhamento do desenvolvimento motor. Objetivo: Revisar sistematicamente os estudos longitudinais que utilizam o teste KTK na iniciação esportiva de crianças e jovens no Brasil, observando sua aplicação em diferentes modalidades esportivas. Metodologia: Foram seguidas as diretrizes para revisão de sistemática do Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Foi realizada a busca nas bases de dados CAPES, SCIELO e Google Acadêmico utilizando: “KTK” AND “coordenação” AND “esportes” NOT “deficiência”. A qualidade metodológica dos estudos incluídos foi avaliada pela ferramenta do Joanna Briggs Institute. Resultados: Foram encontrados 733 estudos, dos quais 15 foram incluídos na revisão. Todos os artigos incluídos resultaram em melhora da coordenação motora após o período de intervenção e o tema está em crescente produção, sendo 40% dos artigos incluídos publicados a partir de 2021. Quanto à classificação Qualis-Capes, 20% dos artigos incluídos foram publi-cados na categoria A. Discussão: Os resultados da presente revisão, mostram que a utilização do teste KTK na população brasileira está de acordo com outros levantamentos realizados com outras populações. Conclusão: O KTK tem sido aplicado na iniciação es-portiva no Brasil, demonstrando que o nível de coordenação motora está positivamente associado à prática esportiva em estudos longitudinais.

O talento esportivo é uma manifestação de altas habilidades e deve ser identificado para ser promovido. O objetivo deste estudo foi criar um índice de avaliação do potencial esportivo de escolares. 1064 estudantes de ambos os sexos de 13 a 17 anos de um colégio militar realizaram uma bateria de testes multidimensional. Os professores avaliaram os seus alunos quanto aos aspectos intangíveis e a expectativa de sucesso esportivo no futuro. O Índice de Potencial Esportivo foi composto pelo somatório dos valores percentis dos seguintes indicadores: força, velocidade, resistência aeróbica, competência percebida, aspectos intangíveis e potencial avaliado pelo professor, com variação de 0 a 100. 11,2% dos meninos (n=70) e 9,4% das meninas (n=40) foram identificados como talentos esportivos (Índice>75). A consistência interna do índice (r>0,70) e a estabilidade do diagnóstico 12 e 24 meses após a primeira avaliação (ICC>0,75) foram elevadas. Os escolares selecionados para os Jogos da Amizade (validade de construto) e aqueles que conquistaram medalhas (validade de critério) apresentaram maior Índice de Potencial Esportivo quando comparados aos não selecionados e não medalhistas. Diante dos resultados, concluiu-se que o Índice de Potencial Esportivo é válido e fidedigno para a estimativa do potencial esportivo de escolares de 13 a 17 anos de ambos os sexos, constituindo uma ferramenta científica inovadora, útil e de fácil aplicação na prática para a identificação de talentos esportivos na escola.

BACKGROUND:Ultramarathon running poses physiological challenges, impacting cardiac function. This systematic review and meta-analysis explore the acute effects of single-stage ultramarathon running on cardiac function. METHODS:Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations were followed. Searches covered Medline, Embase, CINAHL, SPORTDiscus, Web of Science, Central Cochrane, and Scopus. Random effects meta-analyses assessed left ventricular (LV) and right ventricular (RV) variables, expressed as mean differences (MD) with 95% confidence intervals (CI). RESULTS:Among 6972 studies, 17 were included. Post-ultramarathon reductions were found in LV end-diastolic diameter (LVEDD) (-1.24; 95% CI = -1.77, -0.71 mm), LV end-diastolic volume (LVEDV) (-9.92; 95% CI = -15.25, -4.60 ml), LV stroke volume (LVSV) (-8.96 ml, 95% CI -13.20, -4.72 ml), LV ejection fraction (LVEF) (-3.71; 95% CI = -5.21, -2.22%), LV global longitudinal strain (LVGLS) (-1.48; 95% CI = -2.21, -0.76%), E/A (-0.30; 95% CI = -0.38, -0.22 cm/s), .E' (-1.35 cm/s, 95% CI -1.91, -0.79 cm/s), RV fractional area change (RVFAC) (-3.34, 95% CI = -5.84, -0.84%), tricuspid annular plane systolic excursion (TAPSE) (-0.12, 95% CI = -0.22, -0.02 cm), RV global longitudinal strain (RVGLS) (-1.73, 95% CI = -2.87, -0.59%), with increases in RV end-diastolic area (RVEDA) (1.89, 95% CI = 0.63, 3.14 cm2), RV Peak A' (1.32 cm/s, 95% CI 0.20, 2.44), and heart rate (18.24, 95% CI = 15.16, 21.32). No significant differences were observed in LV end-systolic diameter (LVESD), LV end-systolic volume (LVESV), RV end-diastolic diameter (RVEDD), RV Peak E', and RV Peak S'. CONCLUSIONS:Evidence suggests immediate impairment of systolic and diastolic cardiac function post-ultramarathon running.

RESUMO Introdução: A detecção de talentos é um processo dinâmico e multifatorial que deve começar pela escola. Objetivo: Criar um modelo matemático de avaliação do potencial esportivo de escolares para as provas de velocidade, lançamentos e resistência no atletismo, e testar as suas propriedades psicométricas. Métodos: Participaram 2871 escolares de ambos os sexos de 11 a 17 anos de um colégio militar. Os alunos foram submetidos a uma bateria de testes multidimensionais, contendo indicadores antropométricos, físico-motores, psicológicos, socioambientais, maturacionais e de desempenho. 10 professores avaliaram os alunos quanto aos aspectos intangíveis do potencial esportivo e a expectativa de sucesso futuro. Adotando procedimentos analíticos e heurísticos, criou-se o Gold Score Athletics – índice linear, híbrido (testes + olho do treinador) e ponderado, de acordo com a importância de cada indicador em função do tipo de prova. Resultados: Na amostra de validação do modelo (n = 1384), 13,9%, 16,6% e 11,7% dos meninos e 10,9%, 10,1% e 9,1% das meninas foram classificados como elevado potencial (Gold Score ≥ 60) para provas de velocidade, lançamentos e resistência respectivamente. A consistência interna (r = 0,76 a 0,82) e estabilidade do diagnóstico foram elevadas (r = 0,72 a 0,81). O Gold Score Athletics para velocistas, lançadores e corredores de longa distância, para ambos os sexos, foi maior nos estudantes selecionados para uma competição nacional quando comparados aos não selecionados (p < 0,001; d: 0,95 a 1,44) – validade de construto – e maior nos medalhistas em uma competição de Atletismo, realizada dois anos após o diagnóstico, quando comparados aos não medalhistas (p < 0,05; d: 0,62 a 1,87) – validade preditiva. Conclusão: O Gold Score Athletics é um modelo científico válido e fidedigno de avaliação do potencial esportivo de escolares, sendo útil na detecção de talentos para o Atletismo. Nível de Evidência II; Estudo diagnóstico.

ABSTRACT Introduction: Talent detection is a dynamic and multifactorial process that must start at school. Objective: Create a mathematical model for evaluating the sporting potential of schoolchildren for athletics in speed, throwing, and endurance events and to test its psychometric properties. Methods: 2871 schoolchildren of both sexes, from 11 to 17 years old, from a military school participated. Between 2015 and 2019, students were submitted to a multidimensional battery of tests containing anthropometric, physical-motor, psychological, socio-environmental, maturational, and performance indicators. In addition, ten teachers evaluated the students regarding the intangibles aspects of their sporting potential and the expectation of future success during this period. Adopting analytical and heuristic procedures, the Gold Score Athletics was created – linear, hybrid (tests + coaches´ eye), and weighted index, according to each indicator's importance, depending on the event type. Results: In the model validation sample (n = 1384), 13.9%, 16.6%, and 11.7% of boys and 10.9%, 10.1%, and 9.1% of girls were classified as high potential (Gold Score ≥ 60) for speed, throwing and endurance events, respectively. Internal consistency (r = 0.76 to 0.82) and diagnostic stability were high (r = 0.72 to 0.81). The Gold Score Athletics for sprinters, throwers, and long-distance runners, both for boys and girls, was higher in students selected for a national competition when compared to those not selected (p < 0.001; d: 0.95 a 1.44) – construct validity – and higher in medalists in an athletics competition, held two years after diagnosis, when compared to non-medalists (p < 0.05; d: 0.62 a 1.87) – predictive validity. Conclusion: The Gold Score Athletics is a valid and reliable scientific model for evaluating the sport's potential of schoolchildren, being useful in the talents detection for Athletics. Level of Evidence II; Diagnostic study.

A importância da Educação Física escolar como primeira etapa no processo de identificação e desenvolvimento de talentos esportivos tem sido destacada por vários pesquisadores. O objetivo deste estudo foi estabelecer valores normativos (pontos de corte) de indicadores multidimensionais do potencial esportivo em escolares de Educação Física. Participaram deste estudo longitudinal-misto 2794 escolares de ambos os sexos, de 11 a 17 anos, de um colégio militar brasileiro. Os alunos realizaram a bateria de testes do Projeto Atletas de Ouro®, contendo indicadores antropométricos, físico-motores, psicológicos, socioambientais e maturacionais, além dos aspectos intangíveis, segundo a opinião dos professores. Valores de referência foram relatados para meninos e meninas, estratificados por idade, considerando os percentis 10º, 25º, 40º, 50º, 60º, 75º, 90º, 98º para os seguintes testes e medidas: massa corporal, estatura, altura sentado, comprimento de membros inferiores, índice de massa corporal, porcentagem de gordura corporal, teste sentar-e-alcançar, corrida de velocidade de 10m e de 20m, handgrip, salto vertical contramovimento, arremesso de medicineball de 2kg, corrida vai-e-vem de 20m, orientação motivacional, habilidades de coping, suporte familiar e aspectos intangíveis do potencial esportivo. Diferenças entre os sexos foram reportadas. Valores normativos foram estabelecidos para a bateria de testes do Projeto Atletas de Ouro® para auxiliar na identificação e desenvolvimento do potencial esportivo dos escolares.

Introdução: A transição de jovens atletas nas categorias de base do atletismo é um período crítico e pouco estudado. Compreender a estabilidade das variáveis antropométricas, físico-motoras e de desempenho é essencial para otimizar o treinamento e prever o desempenho a longo prazo. Objetivo: Investigar os padrões de estabilidade do desempenho e das variáveis antropométricas e físico-motoras em jovens atletas de atletismo do sexo feminino e masculino durante a transição da categoria sub-16 para sub-20. Método: O estudo, de delineamento longitudinal, avaliou atletas em dois momentos: a primeira avaliação ocorreu na categoria sub-16, e a segunda, após 4 anos para mulheres e 5 anos para homens, na categoria sub-20. Foram realizadas anamnese, questionários para treinadores e pais, medições antropométricas e testes físico-motores (flexibilidade, impulsão vertical, força de membros superiores, 60m e 800m). A maturação biológica foi avaliada pelo percentual da estatura adulta predita. Resultados: Foram encontrados aumentos significativos na maioria das variáveis antropométricas e físico-motoras, tanto nos meninos, quanto nas meninas após 5 e 4 anos de treinamento, respectivamente. E ainda, que os indicadores de estabilidade nos meninos e nas meninas foram, em sua maioria, classificados como elevados e moderados em relação às variáveis antropométricas, físico-motoras, bem como na posição no ranking nacional e na conquista de medalhas. Conclusão: Os resultados indicam que há estabilidade na maioria das variáveis antropométricas e físico-motoras em jovens atletas na transição da categoria sub-16 para sub-20, reforçando a importância do monitoramento contínuo no processo de formação de atletas de atletismo.

Objetivo: Verificar o efeito de atividades físicas combinadas, que contemplaram a prática de alongamentos, exercícios localizados, caminhada e equilíbrio, por um período de 16 semanas, em mulheres idosas, e sua relação com a autonomia funcional, o índice de massa corporal e a pressão arterial. Métodos: 54 idosas foram divididas em dois grupos: experimental (GE) (n = 33), com 68,93 ± 6,83 anos, que participou das atividades propostas, e de controle (GC) (n = 21), com 66,55 ± 6,00 anos. Resultados: Na autonomia funcional, o GE apresentou escores de tempo sempre menores em todos os cinco testes avaliados, o que mostra os benefícios advindos de atividades físicas combinadas. C10M (10,4 ± 4,5 para 7,9 ± 2,3), LPDV (7,9 ± 4,3 para 6,2 ± 3,6), LCLC (63,8 ± 16,5 para 55,8 ± 12,3) e VTC (18,9 ± 8,7 para 15,6 ± 6,9), porém eles ainda continuaram classificados como fracos, com exceção do teste LPS, que passou a ser classificado como regular (12,4 ± 4,3 para 10,5 ± 3,0). O GC praticamente se manteve com valores semelhantes aos do pré-teste. Para o IMC, o GE apresentou diferença após o treinamento (29,0 ± 5,2 para 28,4 ± 5,1), enquanto o GC não obteve diferenças. Em relação à PA, o GE obteve diferença após o treinamento na PAS (145,3 ± 4,3 para 136,2 ± 10,9) e PAD (95,8 ± 8,6 para 85,9 ± 8,6), enquanto o GC apresentou diferenças apenas na PAS (147,8 ± 12,2 para 140,1 ± 12,8). Conclusão: As atividades físicas combinadas exerceram importante papel na melhoria dos itens avaliados em 16 semanas de treinamento para mulheres idosas.

Abstract The knowledge of coaches has been used in research on talent identification and development. The objective was to investigate how Brazilian triathlon coaches identify talents and what is the importance of different factors and indicators for the development of young triathletes. 37 coaches (89% male; 36.2 ± 8.3 years; 43% international competitive level) answered an online questionnaire about anthropometric, physical-motor, technical, tactical, psychological and environmental characteristics. On a scale of 1 (not very important) to 5 (extremely important), coaches indicated to what extent a factor/indicator of sporting potential was important for talent development in triathlon. 45.9% of the coaches perform talent identification, mainly by physical-motor tests and triathlon simulations. In talent development, the physical-motor factor was the most important, followed by the technical, psychological and anthropometric factor, and finally the tactical and environmental factor. Most coaches considered as extremely important the following indicators: determination (70%), aerobic endurance (65%), specific swimming skills (62%), ability to withstand pressure (59%), and efficiency of the cyclic gesture of swimming, cycling, and running (57%). We conclude that Brazilian triathlon coaches identify talents mainly through batteries of tests and triathlon simulations and consider the physical-motor factor the most important for the development of young talented triathletes, but not the only one.

Purpose. Self -regulation of exercise intensity with the Borg 6-20 scale seems a promising alternative, since the magnitude of effort is regulated by internal factors inherent to the individual and their perception of effort during the activity. In order verify this hypothesis, some studies have tested the validity of the Borg 6-20 scale for prescribing exercise intensity. The study aim was to review the literature and verify the validity of the Borg 6-20 scale in aerobic exercise prescription. Methods. The PICOS strategy was used to conduct the search for evidence concerning the objectives of the review recommended by PRISMA-P. The level and quality of evidence were analysed by using the Cochrane Collaboration's recommendation for systematic reviews. Results. A total of 1434 references were found. After applying the criteria of inclusion, 15 studies were considered eligible for review. These studies generally tested the validity of intensity -regulated prescriptions with rating of perceived exertion (RPE) by comparing physiological and performance measures obtained in incremental tests or conventional prescriptions with the measures generated by prescriptions regulated with the Borg 6-20 scale. In addition, some studies evaluated reliability and reproducibility of RPE-regulated prescriptions by comparing physiological and performance measures obtained from different intensity -regulated exercise sessions with the Borg 6-20 scale. Conclusions. According to the studies investigated in this systematic review, the recommendation of the Borg 6-20 in exercise prescription is not yet a valid alternative to describe similar intensity magnitudes to physiological and performance variables.

Introdução: a avaliação do potencial esportivo é uma etapa importante na descoberta de novos talentos e deve utilizar preditores relevantes do desempenho. Objetivo: investigar a importância atribuída por treinadores aos determinantes do desempenho no atletismo, analisando diferenças entre os tipos de prova. Metodologia: participaram 12 treinadores brasileiros de atletismo (11 homens; 83% de Minas Gerais; 75% com experiência no alto rendimento e 42% com títulos internacionais). Aplicou-se um questionário contendo seis fatores e 51 indicadores do desempenho no atletismo. Os treinadores responderam em relação a importância atribuída aos fatores antropométrico, físico-motor, técnico, tático, psicológico e socioambiental, numa escala Likert (1-nada importante e 5-extremamente importante) e a ordem de importância, considerando do 1º ao 6º mais importante. Avaliaram ainda a importância para o desempenho de velocistas, fundistas, saltadores, lançadores e provas combinadas. Resultados e discussão: a ordem de importância dos fatores de desempenho foi: 1º) Físico-motor, 2º) Técnico, 3º) Psicológico, 4º) Antropométrico, 5º) Tático e 6º) Socioambiental. O fator tático, entretanto, foi o mais importante para os fundistas e atletas de provas combinadas. Conclusão: a opinião dos treinadores revelou que as características físico-motoras, técnicas e psicológicas são, nesta ordem, os principais fatores determinantes do desempenho no atletismo. Porém, é preciso considerar as diferenças observadas em relação aos grupos de provas, pois cada um apresenta particularidades que caracterizam um perfil específico.

BACKGROUND: Dissatisfaction with the image, especially in aspects related to body weight, are predominantly present in women, level of dissatisfaction can lead to rejection of your image which is a self-acceptance process present in social groups of the population. The aim of this study was to analyze the level of body image satisfaction in women bodybuilders who practice physical activities of different levels. For this, the anthropometric measurements of 88 participating women were divided into three groups: bodybuilders, physical activity practitioners and undergraduate students in physical education.METHODS: In order to analyze the level of body image satisfaction, the 15-figure Silhouette Scale of the protocol was used. Damascene, including the evaluation of the participants’ Body Mass Index, anthropometric measurements were taken. For the comparison of the three groups, analysis of variance was used as a factor for analysis of age and body size and the Kruskal-Wallis test for silhouette and dissatisfaction values.RESULTS: It was found that there was no difference between the groups regarding current silhouette and dissatisfaction. There was a significant difference when comparing the current bodybuilder and bodybuilder silhouette option with the option of undergraduate students in physical education. Undergraduate students in physical education identified themselves with a smaller silhouette than women bodybuilders and bodybuilders. This is because bodybuilders and gym practitioners have higher hypertrophic volume than sedentary ones.CONCLUSIONS: This result demonstrates that women evaluated the desired silhouettes with greater hypertrophic volume rather than thinner silhouettes, demonstrating a possible tendency for changes in female aesthetic patterns.

There is growing interest in identifying morphological, motor, maturation characteristics, as well as their changes, of children and adolescents in systematized training in various sports. Knowledge of these characteristics is important for coaches and researchers because they provide parameters for assessing youth development during training. For track and field, studies on the category under 16 are scarce. Thus, the objectives of this study are to describe the profile and to design a percentile table of morphological, motor, maturation and event-specific variables of under 16 athletes. 105 young athletes were evaluated on two consecutive days. On the first day, an anamnesis of athletes and coaches was performed. Anthropometric and anaerobic measurements were analyzed in shot put, long jump, 800 m run. On the second day, flexibility, vertical impulse, upper limb strength, speed and maximal aerobic speed were evaluated. The biological maturation was evaluated by the percentage of the predicted height. A table with percentiles was prepared with the data of all athletes. Another table with the results of the whole group plus mean and standard deviation was prepared. A last table was prepared containing data divided by group of sports events. The morphological variables presented differences between the groups as to body mass, BMI and sum of skinfolds. Significant differences were observed only for the motor variable VMA. No significant differences were observed only for long jump. When divided by groups, it was evident that throwers are different from the other athletes in some morphologic variables and in specific sports events.

This study intended to analyze the pacing profiles in 5,000 m and 10,000 m race, men and women, in Brazil Athletics Trophy. Thirty-six high-level runners, being 19 women, participated in this study. The races were filmed (iPhone 8 Plus). The device was positioned on the outside of the track and a cone on the inside edge of the finish line. This procedure allowed the acquisition of lap times. The plotting of the percentage of average speed for each lap of the 400 m within a race was used to analyze the pacing profile adopted. Differences between the laps were analyzed through one-way ANOVA for repeated measures. The significance level was established as p<0.05. In the women’s 5,000 m (1.200 m - 4.000 m; p=0.003-0.045) and 10,000 m (2.400 m - 8.400; p= 0.01-0.04), was employed the positive pacing profile. In men’s race, the varied profile was adopted in 5,000 m race (800m - 1.600m, p=0.001-0.019; 3.200m, p=0.00–0.02; last 200m, p= 0.027) and the constant during 10,000 m race (p= 0.98). In these competitions in which the most important is the finishing positions, opponents' actions can influence the tactical decision. Therefore, to succeed, the athletes should remain in the group and sprint in the race's final meters when the result is defined.

The aim of this study was to describe the pacing during a 6-h ultramarathon (race 1) and to investigate whether a slow-start affects performance, running kinematic changes, ratings of perceived exertion (RPE) and fatigue (ROF) (race 2). After a critical speed test, participants completed two 6-h ultramarathons. Race 1 (n = 16) was self-paced, whereas in race 2 (n = 10), athletes performed the initial 36 min at speeds 18% below the mean speed of the initial 36 min of race 1. In race 1, participants adopted an inverse sigmoid pacing. Contact times increased after 1 h, and flight times decreased after 30 min (all P ≤ .009); stride length reduced after 1 h 30 min (all P = .022), and stride frequency did not change. Despite the lower speeds during the first 10% of race 2, and higher speeds at 50% and 90%, performance remained unchanged (57.5 ± 10.2 vs. 56.3 ± 8.5 km; P = .298). However, RPE and ROF were lowered for most of race 2 duration (all P < .001). For the comparison of kinematic variables between races, data were normalised by absolute running speed at each time point from 1 h onwards. No differences were found for any of the kinematic variables. In conclusion, decreasing initial speed minimises RPE and ROF, but does not necessarily affect performance. In addition, running kinematic changes do not seem to be affected by pacing manipulation.

Objetivo: O objetivo deste estudo foi verificar a concordância entre a intensidade estimada pelos treinadores e a percebida por jovens atletas de atletismo. Método: A amostra foi composta por 50 jovens atletas de atletismo da categoria mirim (13 – 15 anos), sendo 25 meninas e 25 meninos de cinco equipes de atletismo e seus respectivos treinadores. Todos os voluntários foram submetidos ao mesmo protocolo experimental de treinamento para as provas de corrida (75, 250 e 1000 m), salto em distância e arremesso do peso. Para estimar a intensidade da sessão de treinamento, foi usado o método da percepção subjetiva de esforço da sessão. Resultados: Os resultados encontrados demonstram que em média, há alta concordância entre treinadores e atletas (CCI: 0.76; p < 0.01; n = 50). Contudo, quando analisado por prova, é possível perceber falta de concordância para os treinos de arremesso do peso (CCI: -0.01; p = 0.51; n = 50) e corrida de 1000 m (CCI: 0.24; p = 0.16; n = 50), adicionalmente, em média, para a sessão de treinamento de corrida de 1000 m os treinadores subestimam a intensidade da sessão (p < 0.05). Conclusão: Treinadores conseguem estimar com precisão as sessões de treinamento de jovens atletas, exceto para os treinos de arremesso do peso e corrida de 1000 m, onde os treinadores tendem a subestimar a intensidade da sessão de treinamento.

Aims: The aims of this study were: i) to verify whether player internal load (PIL) monitored via heart rate (HR) varies with game-time and playing position; ii) whether intermittent running capacity (IRC) is related to the maintenance of within-match PIL in elite youth (U-15) soccer players. Method: Twenty-one elite soccer players (14±0.5 yrs, 172±7 cm, 63±6 kg) had their heart rate monitored (beats/min) in five matches and were tested twice for IRC (Yo-YoIR2, distance [m]) over a seven-week competitive season. Percentage of maximal heart rate (%HRmax) and time spent (TS%) in five zones (Z1[ 96%]) were our PIL indexes. Data from three complete games in the same position of each player were analyzed and matches halves, time intervals (T1 to T6), and playing positions (fullbacks, central defenders and forwards [N=5 each], midfielders [N=6]) were compared, and the relationship between IRC and within-match PIL was determined. Results: PIL was higher in 1st (86±3%) than in the 2nd half (84±4%; p<.001). The 2nd half had more TS% in Z1 and Z2 (p<.05). PIL in T4 was the lowest (p<.01), and in T6, it was lower than T1 and T2 (p<.01). Fullbacks and midfielders showed higher PIL and higher TS% in Z4 (p<.05) than the other positional roles. The average IRC correlated with PIL in T6 (r=.56, p<.01) only. Conclusion: In conclusion, the internal load in elite youth (U-15) soccer players varies with game-time and playing position; and their IRC is related to the maintenance of within-match PIL.

The assessment of aerobic fitness through the measurement of maximum oxygen consumption (VO2 max) is an objective parameter that integrates cardiovascular, respiratory and metabolic responses, providing a reliable assessment of exercise capacity and health status, as well as being useful information for exercise training prescription. The purpose of this study was to determine a model for predicting Maximum Oxygen Uptake based on HRV parameters estimated at rest in 70 young physically active adults. After recording the resting tacho gram with a cardio-frequency meter to calculate HRV parameters, a maximal cardiopulmonary incremental test was performed to measure the VO2 max. The model for predicting VO2 max was obtained by stepwise multiple linear regression assuming as independent variables the mean RR interval, pNN50 index, and a proposed cardiac deceleration rate. The models were cross-validated by K-fold method, and the best model accounted for 76% of data variance, with a standard error of estimate 4.40mL·kg-1min-1. In conclusion, the obtained model might be tested as a tool for predicting the aerobic fitness in adult males in rest based on the mean RR interval and the pNN50HRV parameters. Thus, the findings are not only interesting but important in that they can be performed without the need of applying a stress test and extend the HRV applicability in the evaluation of aerobic capacity and athletic performance.

Unstable surfaces have been used in resistance training, but there are no studies that compared energy cost between stable and unstable surfaces in circuit weight training. This study compared energy cost, post-exercise peak blood lactate and perceived exertion rate between stable surface and unstable surface. Twenty healthy men (24.65 ± 3.48 years, 1.79 ± 0.08 m, 80.61 ± 9.14 kg and 11.86 ± 3.49% body fat) participated in the study. Test and retest of 15 maximum repetitions were performed on stable and unstable surfaces to define workload. The circuit weight training consisted of one set of 15 repetitions at 80% of 15 maximum repetitions in bench press, back squat, rowing bent prone, dead-lift, shoulder press, elbow extension and elbow flexion. Energy cost was measured by indirect calorimetry during and post-circuit weight training. Peak blood lactate and perceived exertion rate were measured post-exercise. Total energy cost was higher on unstable surface compared to stable surface (70.7 ± 10.0 vs. 66.6 ± 7.8 kcal; p = 0.01), as was perceived exertion rate (8.1 ± 0.9 vs. 7.6 ± 1.3; p = 0.02). However, peak blood lactate was higher on stable than unstable surfaces (13.6 ± 2.6 vs. 12.5 ± 1.9 mmol·L−1; p = 0.05). In conclusion, circuit weight training on unstable surfaces can be performed with less weight in comparison to stable surfaces, thereby lowering mechanical stress on joints and bones, while still providing a higher metabolic impact.

Purpose: This study aimed to compare the energy expenditure and intensity of active video games to that of treadmill walking in children and adolescents. Method: Seventy- two boys and girls (aged 8- 13 years) were recruited from local public schools. Energy expenditure and heart rate were measured during rest, during 3- km/hr, 4- km/hr, and 5- km/hr walks, and during active games (Adventure, Boxing I, Boxing II, and Dance). During walking and active games, we also assessed physical activity using an accelerometer. Results: The energy expenditure of the active games Adventure, Boxing I, Boxing II, and Dance was similar to that of treadmill walking at 5 km/hr in boys and girls. Heart rate was significantly higher for the game Adventure compared with walking at 3 km/hr, 4 km/hr, and 5 km/hr and the game Dance in both genders. The heart rate of girls during the games Adventure and Dance was significantly higher compared with boys. There was a statistically significant difference (p<.05, with an effect size ranging from 0.40 to 3.54) in the counts center dot min(-1), measured through accelerometry, between activities. Conclusion: XBOX 360 Kinect games provide energy expenditure and physical activity of moderate intensity for both genders. The use of active video games can be an interesting alternative to increase physical activity levels.