The use of wearable resistance and weighted vest for sprint performance and kinematics: a systematic review and meta-analysis.

Wearable resistance (WR) and weighted vests (WV) can be used in almost all training conditions to enhance sprint performance; however, positioning and additional mass are different in WV and WR strategies, affecting performance and kinematics differently. We aimed to systematically review the literature, searching for intervention studies that reported the acute or chronic kinematic and performance impact of WV and WR and comparing them. We analyzed Pubmed, Embase, Scopus, and SPORTDiscuss databases for longitudinal and cross-over studies investigating sprint performance or kinematics using an inverse-variance with a random-effect method for meta-analysis. After the eligibility assessment, 25 studies were included in the meta-analysis. Cross-over WR and WV studies found significantly higher sprint times and higher ground contact times (CT) compared to unloaded (UL) conditions. However, WR presented a lower step frequency (SF) compared to UL, whereas WV presented a lower step length (SL). Only one study investigated the chronic adaptations for WR, indicating a superiority of the WR group on sprint time compared to the control group. However, no difference was found chronically for WV regarding sprint time, CT, and flight time (FT). Our findings suggest that using WV and WR in field sports demonstrates overload sprint gesture through kinematic changes, however, WR can be more suitable for SF-reliant athletes and WV for SL-reliant athletes. Although promising for chronic performance improvement, coaches and athletes should carefully consider WV and WR use since there is no supporting evidence that WV or WR will impact sprint performance, CT, and FT.

Innovative integration: optimizing performance through warm-up and photobiomodulation in high-intensity test.

We investigated whether the application of photobiomodulation therapy (PBMT) immediately after a standardized warm-up (WU + PBMT) or traditional PBMT (no pre-warming) would influence performance in intermittent testing and intensity variables. In a counterbalanced randomized crossover design, twelve female futsal players (mean age: 23.9 ± 3.8 years) attended four sessions. Each session involved either a standardized warm-up or maintaining seated rest for five minutes. Subsequently, PBMT or placebo (with the PBMT device turned off) was applied, followed by the YoYo Intermittent Recovery Level 1 test (YYIR1) during which we assessed heart rate, rating of perceived exertion, and blood lactate levels. The performance in YYIIR1 was superior (p = 0.02) in the WU + PBMT condition (440.0 ± 59.0 m) compared to the WU + Placebo (353.3 ± 94.7 m), and placebo alone (no warm-up) (325.0 ± 67.2 m). We conclude that a combination of a specific warm-up before PBMT application improves high-intensity intermittent performance in amateur female futsal players without affecting intensity variables.

Impact of Complete Intermittent Blood Flow Restriction in Upper Limbs Strength and Neural Function.

Purpose: We aimed to investigate the chronic effects of low-load strength training (LT) with complete intermittent blood flow restriction (IBFR) on neural adaptations and strength in biceps brachii. Methods: Nineteen volunteers were randomly assigned into two different 9-week training protocols consisting of three assessment weeks and six training weeks: (a) LT with complete IBFR (LT-IBFR; n = 10) and (b) LT without complete IBFR (LT; n = 9). Strength was evaluated by predicted 1 repetition maximum (1RM) at weeks 1, 5, and 9 and neural function by root mean square (RMS) and median frequency (MDF) at sessions 1, 7, and 12 during the first three and last three repetitions. Both groups performed three sets of Scott curl with 20% of predicted 1RM interspersed with 90s rest twice a week. Results: No changes were found in predicted 1RM throughout the training protocols nor between groups. LT-IBFR group showed lower RMS in the first set than LT for the first three repetitions and higher RMS in all sets for the last three repetitions with decreases in this value across the sets with no longitudinal changes for both groups. MDF in the first three repetitions did not differentiate between groups, however, in the last three repetitions, MDF were lower for LTIBFR group in all sets and it increased across the sets for this condition with no chronical changes for both groups in both repetitions zones. These results suggest that LT-IBFR may be ineffective for increasing Q5 strength and it did not promote chronic neural adaptations.

The Percentage of Total and Regional Fat Is Negatively Correlated with Performance in Judo.

This study investigated the associations between total and regional body composition with performance in the special judo fitness test (SJFT), as well as strength and power tests (countermovement vertical jump-CMJ, squat jump-SJ, plyometric push-up-PPU, and force push-up-FPU). Twenty-three high-level judo athletes participated in this study. Initially, they underwent dual-energy X-ray absorptiometry, after which they performed the CMJ, SJ, PPU, and FPU tests. On another day, the SJFT was carried out. Correlations were tested using Pearson's test. The performance in the SJFT was correlated with the total and arm %fat mass (r = -0.759), torso fat mass (r = -0.802), torso %fat mass (r = -0.822) and in the lower limb regions with the leg fat mass (r = -0.803) and leg %fat (r = -0.745). In the strength and power tests, there were also negative correlations observed between regional fat and performance. There was a negative correlation between the percentage of total fat and performance in the SJFT (r = -0.824), SJ (r = -0.750), CMJ (r = -0.742), PPU (r = -0.609), and FPU (r = -0.736). Fat, both total fat and regional fat in the arms, torso, and legs, is strongly correlated with a poor performance in the SJFT and poor strength and power.

The effects of high-intensity functional training on muscle damage and recovery capacity in trained individuals / Los efectos del entrenamiento funcional de alta intensidad sobre el daño muscular y la capacidad de recuperación en individuos entrenados

Objective: High-Intensity Functional Training (HIFT) is nowadays widely used due to low time demand and efficiency to improve performance and health. The dynamics of recovery of muscle damage and physical fitness after a HIFT in individuals with different fitness status provide a practical informationfor coaches and practitioners. Therefore, the aim of this study was to verify the muscle damage and performance recovery responses after an acute HIFTsession in healthy young men with different fitness status. Method: Sixteen recreationally trained participants (age: 23.4 ± 2.4 y; body mass index: 24.6 ± 2.4 kg·m-2; 1RM back squat: 120.1 ± 19.9 kg) were dividedinto two groups according to their maximum strength (higher-trained [HT] and lower-trained group [LT]), and performed a single HIFT session. Muscledamage (creatine kinase [CK] and lactate dehydrogenase [LDH]) and physical fitness tests (strength, power, and oxygen consumption) were analyzedbefore, immediately after, 24h and 48h after the HIFT session. The internal training load for both groups was equalized using the Rating of PerceivedExertion method (RPE) and the percentage 1 repetition maximum (1RM). Results: Biochemical markers and performance indicators showed that both groups suffered exercise-induced muscle damage. There was a trend towardsfaster muscle damage recovery in HT group.Conclusions: HT group showed higher muscle damage recovery compared to the LT group. A longer recovery time to complete muscle recovery might beexpected in the LT group.(AU)

Objetivo: El Entrenamiento Funcional de Alta Intensidad (HIFT) se utiliza hoy en día ampliamente debido a la baja demanda de tiempo y la eficiencia para mejorar el rendimiento y la salud. La dinámica de recuperación del daño muscular y la forma física después de un HIFT en individuos con diferentes estados de forma proporcionan una información práctica para entrenadores y profesionales. Por lo tanto, el objetivo de este estudio fue verificar el daño muscular y las respuestas de recuperación del rendimiento después de una sesión aguda de HIFT en hombres jóvenes sanos con diferentes estados de forma física. Método: Dieciséis participantes entrenados de forma recreativa (edad: 23,4 ± 2,4 y; índice de masa corporal: 24,6 ± 2,4 kg-m-2; 1RM back squat: 120,1 ± 19,9 kg) se dividieron en dos grupos en función de su fuerza máxima (grupo de mayor entrenamiento [HT] y grupo de menor entrenamiento [LT]), y realizaron una única sesión de HIFT. Se analizaron el daño muscular (creatina quinasa [CK] y lactato deshidrogenasa [LDH]) y las pruebas de aptitud física (fuerza, potencia y consumo de oxígeno) antes, inmediatamente después, 24h y 48h después de la sesión de HIFT. La carga de entrenamiento interna para ambos grupos se igualó utilizando el método de Valoración del Esfuerzo Percibido (RPE) y el porcentaje de 1 repetición máxima (1RM). Resultados: Los marcadores bioquímicos y los indicadores de rendimiento mostraron que ambos grupos sufrieron daños musculares inducidos por el ejercicio. Hubo una tendencia a una recuperación más rápida del daño muscular en el grupo HT. Conclusiones: El grupo HT mostró una mayor recuperación del daño muscular en comparación con el grupo LT. Podría esperarse un mayor tiempo de recuperación hasta la recuperación muscular completa en el grupo LT.(AU)

Association Between Foundation Strength and Weightlifting Exercises in Highly Trained Weightlifters: Support for a General Strength Component.

ABSTRACT: Zecchin, A, Puggina, EF, Hortobágyi, T, and Granacher, U. Association between foundation strength and weightlifting exercises in highly trained weightlifters: support for a general strength component. J Strength Cond Res 37(7): 1375-1381, 2023-In addition to specific weightlifting exercises (i.e., clean and jerk and snatch), foundation strength exercises (i.e., overhead press, front squat, and deadlift) constitute an integral part of the weightlifters' training regime. The unexamined concept behind this training plan is that foundation strength exercises are associated with clean and jerk and snatch performance, implying the existence of a general strength component. We thus determined the relationship between performance in foundation strength exercises (overhead press, front squat, and deadlift) and weightlifting exercises (clean and jerk and snatch) in weightlifters. Well-trained weightlifters ( N = 19, age: 26.8 ± 4.4 years; body mass index: 27.6 ± 2.3 kg·m -2 ; and training history: 4.6 ± 0.8 years) performed 1 repetition maximum tests (1RM) in foundation strength and weightlifting exercises, over 14 days, in a randomized order. We observed significant correlations in 1RM performance between the overhead press and snatch ( r = 0.69), front squat and snatch ( r = 0.73), overhead press and clean and jerk ( r = 0.67), and front squat and clean and jerk ( r = 0.72, all r values: p < 0.01). No significant correlations were found for 1RM performance between the snatch and deadlift or between the clean and jerk and deadlift ( r- range: 0.20-0.58; p > 0.05). Stepwise linear regression revealed that 1RM performance in the overhead press and front squat explained 62% of the variance in snatch 1RM performance ( F = 5.51; p < 0.04). Overhead press and front squat 1RM performance explained 59% of the variance in the clean and jerk 1RM performance ( F = 5.14; p < 0.04). Our results demonstrate the existence of a general strength component between selected foundation strength exercises and weightlifting performance. However, the use of the front squat and overhead press to increase 1RM performance in weightlifting exercises needs to be determined in future research using a different methodological approach (i.e., longitudinal protocols), given that the observed correlations do not necessarily imply causation.

Strength training with and without arteriovenous blood flow restriction improves performance, regardless of changes in muscle hypertrophy, in Wistar rats.

Strength training (ST) with blood flow restriction (BFR) is known to promote increases in hypertrophy and strength sometimes similar to traditional ST despite the effects of the arterial BFR on muscle adaptations and safety are not well established. The aim of this study was to assess whether ST with arterial BFR is able to improve muscular adaptations, performance and its safety in Wistar rats. Animals aging 8 weeks were divided in four groups: sedentary sham (S/S), sedentary with arterial BFR (S/BFR), trained sham (T/S), and trained with arterial BFR (T/BFR). Training protocol consisted of four weeks of ST composed by six sets of 10 ladder climbing with 50% of 1 maximal voluntary contraction. Body weight, epididymal fat, maximum loaded weight, manual grip strength, muscular hypertrophy index, systolic blood pressure, enzyme activity of superoxide dismutase, nitrite/nitrate concentration and tumor necrosis factor alpha were analyzed. The BFR rate was between 36% and 38%. T/BRF was effective to promote strength and hypertrophy. T/S is an alternative to improve strength, but it did not promote hypertrophy. Furthermore, we found no significant cardiac and metabolic changes. Thus, T/BFR is able to improve muscle adaptations and performance in rats, without causing cardiovascular and metabolic damage.

Análisis de redes sociales en el deporte desde el punto de vista del enfoque ecológico

Meli Neto, B., Fuini Puggina, E., Pombo Menezes, R., Cláudio Machado, J., Vanella, R., y Aquino, R. (2022). Análisis de redes sociales en el deporte desde el punto de vista del enfoque ecológico. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 20(1), 1-21. El análisis del rendimiento está relacionado con la pedagogía del deporte. Las bases teóricas que sustentan las selecciones metodológicas deben estar bien establecidas para que haya una convergencia entre los instrumentos de evaluación y el proceso de enseñanza y entrenamiento. Este ensayo pretende presentar y discutir la importancia y representatividad del análisis de redes sociales para evaluar el rendimiento en los deportes de equipo. El objetivo principal del análisis de redes sociales es estudiar la relación entre los jugadores para identificar las posibles causas y consecuencias de los eventos durante el partido. Así, el análisis de redes sociales es diferente de los análisis tradicionales, en los que el foco principal está en el sujeto, o de los análisis notacionales, que son más utilizados y acumulan la frecuencia de los eventos ocurridos (por ejemplo, los goles marcados, la posesión del balón, las zonas de remate). Esta herramienta de evaluación, posicionada teóricamente en un enfoque ecológico, se muestra eficaz para la identificación de los patrones de interacción en un grupo y la comprensión de los artificios sociales que ayudan a entender el rendimiento de un equipo. Así, los equipos pasan a ser analizados como grupos sociales y no como sujetos aislados. En este ensayo también se exponen las principales aplicaciones prácticas de esta herramienta de evaluación en diferentes deportes de equipo como el fútbol, el fútbol sala, el balonmano, el baloncesto y el voleibol.

Meli Neto, B., Fuini Puggina, E., Pombo Menezes, R., Cláudio Machado, J., Vanella, R., e Aquino, R. (2022). Análise de redes sociais no esporte pela ótica da abordagem ecológica: um ensaio teórico. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 20(1), 1-21. A análise de desempenho é uma disciplina intimamente relacionada à pedagogia do esporte. As bases teóricas que sustentam as escolhas metodológicas devem ser bem estabelecidas para existir uma convergência entre os instrumentos de avaliação e o processo de ensino e treinamento. Este ensaio teórico teve por objetivo apresentar e discutir a importância e representatividade da análise de redes sociais para avaliar o desempenho em esportes coletivos. O principal objetivo da análise de redes sociais é estudar a relação entre os jogadores para identificar possíveis causas e consequências dos eventos ocorridos durante a partida. Sendo assim, a análise de redes sociais trabalha de forma diferente das análises tradicionais, nas quais o principal foco está no sujeito, ou em análises notacionais que são as mais comumente utilizadas e que buscam a acumulação da frequência dos eventos ocorridos (e.g. gols marcados, posse de bola, áreas de finalização das jogadas). Tal instrumento de avaliação, teoricamente posicionado numa abordagem ecológica, mostra-se eficaz para a identificação de padrões de interação num grupo e o entendimento dos artifícios sociais que ajudam a compreender o desempenho em uma equipe. Assim, as equipes passam a ser analisadas como grupos sociais e não como sujeitos isolados. Neste ensaio, também se apresentam as principais aplicações práticas desse instrumento de avaliação em diferentes esportes coletivos, tais como o futebol, o futsal, o handebol, o basquetebol e o voleibol.

Meli Neto, B., Fuini Puggina, E., Pombo Menezes, R., Cláudio Machado, J., Vanella, R., & Aquino, R. (2022). Social networks analysis in sports through an ecological approach—a theoretical framework. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 20(1), 1-21. Performance analysis is a discipline that is closely related to the pedagogy of sports. The theoretical foundations that undergird methodological choices must be well established in order for a convergence to exist between evaluation instruments and the process of teaching and training. The objective of the present theoretical study was to present and discuss the importance and representativeness of social networks analysis in order to evaluate the performance in group sports. The main purpose of social networks analysis is to study the relationships among players, in order to identify possible causes and consequences of the events that took place during a match. Thus, the analysis of social networks works differently from traditional analyses, whose major focus is on the subject, or in notational analyses that are most commonly used and that look for the accumulation of frequency of the events that have occurred (e.g., goals scored, ball possession, finishing zones). Such an instrument of evaluation, theoretically positioned on an ecological approach, proves effective for the identification of interaction patterns in a group and for understanding the social artifices that help to understand performance in a team. Thus, teams come to be analyzed as social groups instead of isolated individuals. This study also presents the main practical applications of this evaluation instrument in different group sports such as soccer football, indoor soccer, handball, basketball and volleyball.

Internal load in male professional volleyball: a systematic review.

INTRODUCTION: The aims of this systematic review were to synthesize the volleyball internal load values presents in the literature, verify the applicability of the different tools for quantification and monitoring these variables, and analyze the similarity with the matches and training loads. EVIDENCE ACQUISITION: This review followed the PRISMA statement recommendations, and the search was carried out in the databases: PubMed/NCBI, SportDiscus via EBSCOhost, SciELO and in the Brazilian Library of Theses. Twenty-six studies meet the criteria and were included. EVIDENCE SYNTHESIS: The most used and indicate tools for quantification, monitoring and evaluation of volleyball internal load are the rating of perceived exertion (RPE), session rating of perceived exertion (sRPE) and other metrics derived from these data. Volleyball training sessions range from 4 to 7 in Brog Scale and sessions with more jumps present a higher load. The sRPE values found ranged from 51.92 (AU) to 627 (AU) and presents an undulating kinetic intra and inter weeks. Higher total week training load values are observed in the preparatory period than in competitive periods and wellbeing and recovery questionnaires are sensible to increased loads. CONCLUSIONS: In professional male volleyball, training load seem to be planned with variation according to the period of the season and days of week. The intraweek variation in load dynamics is necessary to allow the correct athlete's recovery and adaptation to volleyball efforts and the interweek load increase can be monitored by the ACWR.

Low load strength training, associated with or without blood flow restriction increased NO production and decreased production of reactive oxygen species in rats aorta.

Studies have shown that strength training (ST) with blood flow restriction (BFR) in which low load is used (20-50% of 1 maximum voluntary contraction - MVC) can produce positive adaptations similar to ST with loads equal to or greater than 70% 1 MVC. Furthermore, recent studies have investigated the effects of STBFR on muscle adaptations, but few studies investigated the effects of STBFR on vascular function. This study aimed to evaluate the effects of the STBFR program on the vascular reactivity of the abdominal aorta of Wistar rats with femoral arteriovenous blood flow restriction. Male rats were divided into four groups: sedentary sham (S/S), sedentary with blood flow restriction (S/BFR), trained sham (T/S), and trained with blood flow restriction (T/BFR). The animals in the S/BFR and T/BFR groups underwent surgery to BFR in the femoral artery and vein. After one week, the trained groups started the ST which consisted of climbing ladder, six sets of 10 repetitions with 50% of 1 MVC assessed by maximum loaded weight (MLW) carried out for four weeks. Concentration-response curves to Acetylcholine (ACh: 10 nM - 100 µM) and Phenylephrine (PHE: 1 nM - 30 µM) were performed in aortic rings with intact endothelium. The production of nitric oxide (NO) and reactive oxygen species (ROS) in situ and the vascular remodeling marker (MMP-2) were also measured. The ST increased the strength of the T/S and T/BFR groups in MLW tests. The S/BFR group showed a 22% reduction in relaxation to acetylcholine, but exercise prevented this reduction in the T/BFR group. In animals without BFR, ST did not alter the response to acetylcholine. An increase in NO production was seen in T/S and T/BFR showed a reduction in ROS production (62% and 40%, respectively). In conclusion low load ST with BFR promotes similar vascular function responses to ST without BFR. Low load ST with and without BFR is interventions that can improve performance with similar magnitudes. Both training methods could have some benefits for vascular health due to NO production in the aorta increased in the T/S group and decreased production of reactive oxygen species in the T/BFR group.

Two days of simulated CrossFit competition affect autonomic nervous system but not anaerobic power or fatigue.

BACKGROUND: We examined changes in autonomic nervous system function, anaerobic power, and fatigue over two days of simulated CrossFit competition in CrossFit athletes. In addition, we determined the relationship between these internal training load variables and variables characterizing two weeks of tapering preceding the competition. METHODS: In total, 21 participants (intervention group, N.=10, INT; control group, N.=11, CON) completed the assessments. INT performed the assessments at baseline (pre-day 1), during the competition (post-day 1 and pre-day 2), and after the competition (post-day 2), while CON performed only the baseline assessments. RESULTS: Autonomic nervous system function, anaerobic power, and fatigue did not differ between the beginning of day 1 and day 2. Autonomic nervous system function was impaired at the end of each day. Anaerobic power and fatigue did not change during either day. CONCLUSIONS: Finally, the two training weeks preceding the two days of simulated competition were related to anaerobic power but not autonomic nervous system function or fatigue. CrossFit coaches and athletes should be aware of the limited effects of step taper on heart rate variability and fatigue.

Análise de redes socialis pela óptica da abordagem ecológica: un ensaio teórico / Social networks analysis in sports through an ecological approach: a theoretical framework

Resumo Meli Neto, B., Fuini Puggina, E., Pombo Menezes, R., Cláudio Machado, J., Vanella, R. e Aquino, R. (2021). Análise de redes sociais no esporte pela ótica da abordagem ecológica: um ensaio teórico. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 19(2), 1-19. A análise de desempenho é uma disciplina intimamente relacionada à pedagogia do esporte. As bases teóricas que sustentam as escolhas metodológicas devem ser bem estabelecidas para existir uma convergência entre os instrumentos de avaliação e o processo de ensino e treinamento. Este ensaio teórico teve por objetivo apresentar e discutir a importância e representatividade da análise de redes sociais para avaliar o desempenho em esportes coletivos. O principal objetivo da análise de redes sociais é estudar a relação entre os jogadores para identificar possíveis causas e consequências dos eventos ocorridos durante a partida. Sendo assim, a análise de redes sociais trabalha de forma diferente das análises tradicionais, nas quais o principal foco está no sujeito, ou em análises notacionais que são as mais comumente utilizadas e que buscam a acumulação da frequência dos eventos ocorridos (e.g. gols marcados, posse de bola, áreas de finalização das jogadas). Tal instrumento de avaliação, teoricamente posicionado numa abordagem ecológica, mostra-se eficaz para a identificação de padrões de interação num grupo e o entendimento dos artifícios sociais que ajudam a compreender o desempenho em uma equipe. Assim, as equipes passam a ser analisadas como grupos sociais e não como sujeitos isolados. Neste ensaio, também se apresentam as principais aplicações práticas desse instrumento de avaliação em diferentes esportes coletivos, tais como o futebol, o futsal, o handebol, o basquetebol e o voleibol.

Abstract Meli Neto, B., Fuini Puggina, E., Pombo Menezes, R., Cláudio Machado, J., Vanella, R. & Aquino, R. (2021). Social networks analysis in sports through an ecological approach—a theoretical framework. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 19(2), 1-19. Performance analysis is a discipline that is closely related to the pedagogy of sports. The theoretical foundations that undergird methodological choices must be well established in order for a convergence to exist between evaluation instruments and the process of teaching and training. The objective of the present theoretical study was to present and discuss the importance and representativeness of social networks analysis in order to evaluate the performance in group sports. The main purpose of social networks analysis is to study the relationships among players, in order to identify possible causes and consequences of the events that took place during a match. Thus, the analysis of social networks works differently from traditional analyses, whose major focus is on the subject, or in notational analyses that are most commonly used and that look for the accumulation of frequency of the events that have occurred (e.g., goals scored, ball possession, finishing zones). Such an instrument of evaluation, theoretically positioned on an ecological approach, proves effective for the identification of interaction patterns in a group and for understanding the social artifices that help to understand performance in a team. Thus, teams come to be analyzed as social groups instead of isolated individuals. This study also presents the main practical applications of this evaluation instrument in different group sports such as soccer football, indoor soccer, handball, basketball and volleyball.

Resumen Meli Neto, B., Fuini Puggina, E., Pombo Menezes, R., Cláudio Machado, J., Vanella, R. y Aquino, R. (2021). Análisis de redes sociales en el deporte desde el punto de vista del enfoque ecológico. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 19(2), 1-19. El análisis del rendimiento está relacionado con la pedagogía del deporte. Las bases teóricas que sustentan las selecciones metodológicas deben estar bien establecidas para que haya una convergencia entre los instrumentos de evaluación y el proceso de enseñanza y entrenamiento. Este ensayo pretende presentar y discutir la importancia y representatividad del análisis de redes sociales para evaluar el rendimiento en los deportes de equipo. El objetivo principal del análisis de redes sociales es estudiar la relación entre los jugadores para identificar las posibles causas y consecuencias de los eventos durante el partido. Así, el análisis de redes sociales es diferente de los análisis tradicionales, en los que el foco principal está en el sujeto, o de los análisis notacionales, que son más utilizados y acumulan la frecuencia de los eventos ocurridos (por ejemplo, los goles marcados, la posesión del balón, las zonas de remate). Esta herramienta de evaluación, posicionada teóricamente en un enfoque ecológico, se muestra eficaz para la identificación de los patrones de interacción en un grupo y la comprensión de los artificios sociales que ayudan a entender el rendimiento de un equipo. Así, los equipos pasan a ser analizados como grupos sociales y no como sujetos aislados. En este ensayo, también se exponen las principales aplicaciones prácticas de esta herramienta de evaluación en diferentes deportes de equipo, como el fútbol, el fútbol sala, el balonmano, el baloncesto y el voleibol.

High plasma soluble levels of the immune checkpoint HLA-G molecule among bodybuilders.

INTRODUCTION: Studies report that intense physical activity influences the down-regulation of immune function in athletes as well as the interaction between adipose tissue and the immune system. AIM: This study aimed to compare the plasma soluble levels of the immune checkpoint HLA-G (sHLA-G) molecule with the fat mass and muscle mass index among 77 bodybuilders and 64 controls. RESULTS: The comparisons of the percentage of body fat (%BF) revealed that the groups of male and female bodybuilders showed a statistically significant reduction in the percentage of body fat when compared to their control group, (P <0.0001, for both comparisons). Regarding sHLA-G levels, the comparisons showed that the group of male bodybuilders had significantly higher sHLA-G levels compared to the group of female bodybuilders (P = 0.0011). CONCLUSION: Our results showed that in bodybuilders with less body fat, the systemic levels of soluble HLA-G, an immunological molecule with recognized immunosuppressive function, are significantly higher and suggest that this immune mechanism may corroborate the immunosuppressive state in athletes undergoing intense and prolonged physical training.

Influence of Situational Variables, Team Formation, and Playing Position on Match Running Performance and Social Network Analysis in Brazilian Professional Soccer Players.

Aquino, R, Carling, C, Palucci Vieira, LH, Martins, G, Jabor, G, Machado, J, Santiago, P, Garganta, J, and Puggina, E. Influence of situational variables, team formation, and playing position on match running performance and social network analysis of brazilian professional soccer players. J Strength Cond Res 34(3): 808-817, 2020-The purpose of this study was to investigate the independent and interactive effects of situational variables, opposition team formation, and playing position on running performance and network analysis in Brazilian professional soccer players (n = 22). Global positioning system technology was used to determine total distance covered, mean speed, maximum running speed, and distance covered in 6 speed ranges. Social network analysis was used to assess interpersonal coordination (team interactions characterized as successful passes [n = 3,033] between teammates). Observations of match running performance (n = 129) and network analysis (n = 108) were obtained. The main results were: (a) no interactive effects between team formation and playing position were observed for running and network variables (unclear to possibly); (b) matches played at home or against "weaker" opponents presented greater running demands and individual/global metrics of network analysis (likely to almost certain); (c) match outcome demonstrated influence only for running performance; matches in which the reference team won resulted in higher values than in matches lost; (d) when the reference team competed in 1-4-4-2 formation, this resulted in greater running demands than 1-4-2-3-1 formation (likely to almost certain); (e) reduced values of running performance variables were reported in central defenders compared with other positions. Central/external midfielders reported greater closeness/betweenness centrality, outdegree, and eigenvector compared with central/external defenders and forwards (likely to almost certain). The results from this study provide practical information to potentially impact on physical, tactical, and technical training.

Long distance training associated to HIIT protocol does not induce changes in blood biochemical markers in adult marathoners

ABSTRACT Objective: to verify blood markers during a 12-week training protocol and after Sao Paulo Marathon. Methods: Blood samples of 9 male marathoners were collected before (C1) and after (C2) 12-week training protocol, before (C3) and after (C4) marathon. Muscle and liver damage markers (creatine kinase [CK-MM], aspartate aminotransferase [AST], alanine aminotransferase [ALT]), oxidative stress levels (thiobarbituric acid reactive substances [TBARS]) and serum iron concentration were measured. Results: changes were identified comparing moment C4 to other moments for CK-MM and iron. For AST, ALT, and TBARS no differences were identified. Conclusion: strenuous exercises might elicit changes on blood markers, needing follow up strategies to avoid impairments to athletes' performance and health.

RESUMO Objetivo: verificar marcadores sanguíneos durante 12 semanas de treinamento e após a Maratona de São Paulo. Metodologia: amostras de sangue de 9 maratonistas foram coletadas antes (C1) e após (C2) o treinamento de 12 semanas, antes (C3) e após (C4) a maratona. Marcadores sanguíneos e hepáticos (creatina quinase [CK-MM], aspartato aminotransf. [AST], alanina aminotransf. [ALT]), níveis de estresse oxidativo (subst. reativas ácido tiobarbitúrico [TBARS]) e ferro sérico foram analisados. Resultados: Verificaram-se alterações de CK-MM e ferro entre C4 e os outros momentos. Para AST, ALT e TBARS não se encontrou diferenças. Conclusão: exercícios exaustivos podem causar alterações em marcadores sanguíneos, requerendo estratégias de monitoramento para evitar danos ao desempenho e saúde do atleta.

RESUMEN Objetivo: evaluar marcadores sanguíneos durante 12 semanas de entrenamiento y después del Maratón de São Paulo. Metodología: muestras de sangre de 9 maratonistas fueron recogidas antes (C1) y después (C2) el entrenamiento, y antes (C3) y después (C4) a maratón. Se analizaron marcadores sanguíneos y hepáticos (creatina quinasa [CK-MM], aspartato aminotransf. [AST], alanina aminotransf. [ALT]), estrés oxidativo (sustancias reactivas del ácido tiobarbitúrico [TBARS]) y de hierro. Resultados: Se encontraron cambios comparando C4 y otros momentos para CK-MM y hierro. Para AST, ALT y TBARS no se encontraron diferencias. Conclusión: ejercicios extenuantes pueden causar cambios en marcadores sanguíneos, requiriendo estrategias de monitoreo para evitar daños al desempeño y salud del atleta.

Relações entre flexibilidade de membros inferiores e índice de lesões em modalidades de resistência / Lower limb flexibility and injury index relationship on resistance modalities / Relación entre la flexibilidad de los miembros inferiores y el índice de lesiones en las modalidades de resistencia

Resumo O objetivo deste estudo transversal foi analisar as possíveis relações entre a flexibilidade de membros inferiores com histórico de lesões em modalidades de resistência: ciclismo, corrida, natação e triathlon. Vinte atletas de cada modalidade foram submetidos a um questionário e posteriormente a uma avaliação da flexibilidade por meio da goniometria que investigaram articulações que compreendem movimentação de quadril, joelho e tornozelo. Foram encontradas relações significantes entre a flexibilidade e o histórico de lesões. Essas relações foram positivas para corrida e triathlon e negativa para corrida. Também foi evidenciado que a flexibilidade específica de algumas porções referente a membros inferiores tem relações positivas e negativas com o histórico de lesão em regiões específicas do corpo. Conclui-se que a flexibilidade pode ter tido influência no histórico lesivo do praticante e essa relação é diferente entre modalidades de resistência.

Abstract The aim of this cross-section study was to analyze the possible relationships between lower limb flexibility and injury history in resistance modalities: cycling, running, swimming and triathlon. Twenty athletes of each modality were submitted to a questionnaire and later to an evaluation of flexibility through goniometry, investigating joints that comprise movement of: hip, knee and ankle. Significant relationships between flexibility and the history of injuries were found. Being the positive relations for running and triathlon and negative for running. It has also been shown that the specific flexibility of some portions regarding lower limbs has positive and negative relationships with the injury history in specific regions of the body. It is concluded that flexibility may have had an influence on the practitioner's harmful history and this relationship is different between modalities of resistance.

Resumen El objetivo de este estudio transversal fue analizar las posibles relaciones entre la flexibilidad de los miembros inferiores y un historial de lesiones en modalidades de resistencia: ciclismo, atletismo, natación y triatlón. Veinte atletas de cada modalidad respondieron a un cuestionario y, posteriormente, se valoró su flexibilidad por medio de goniometría, para analizar las articulaciones que implican un movimiento de cadera, rodilla y tobillo. Se encontraron relaciones importantes entre la flexibilidad y el historial de lesiones. Estas relaciones fueron positivas en el atletismo y el triatlón, y negativas en el atletismo. También se puso de manifiesto que la flexibilidad específica de algunas partes de los miembros inferiores tiene relaciones positivas y negativas con el historial de lesión en regiones específicas del miembro inferior. Se concluye que la flexibilidad puede haber influido en el historial lesivo del deportista y esta relación es diferente en función de la modalidad de resistencia.

Validity and reliability of a 6-a-side small-sided game as an indicator of match-related physical performance in elite youth Brazilian soccer players.

The aims of this study were: (i) to compare the external and internal load during a 6-a-side small-sided game (6v6-SSG) according to age-group; (ii) to relate these parameters between the 6v6-SSG and official matches; and (iii) to test the reliability of the 6v6-SSG. A total of 51 Brazilian youth soccer players participated in this study (U11 [n = 16]; U13 [n = 10]; U15 [n = 9]; U17 [n = 8]; U20 [n = 8]). Three experiments were conducted. Experiment A: fifty-one U11 to U20 players were submitted to 6v6-SSGs (n = 10 games; two for each age-group). Experiment B: thirty-two players were randomized to also play official matches (n = 6 matches). Experiment C: thirty-five youth players played the 6v6-SSG twice for test and retest reliability analysis. External load was obtained using Global Positioning Systems and the internal load parameter was calculated through mean heart rate. Statistical approaches showed progressive increases in all parameters according to categories (U11< U13< U15< U17< U20; p < 0.05; ES = 0.42-23.68). Even controlling for chronological age, all parameters showed likely to almost certain correlations between 6v6-SSG and official matches (r = 0.25-0.92). Collectively, the proposed protocol indicates good reliability (CV% = 2.0-12.6; TE% = 2.3-2.7%; ICC = 0.78-0.90). This research suggests that the 6v6-SSG is an alternative tool to indicate match-related physical performance in youth soccer players.

Running Performance in Brazilian Professional Football Players During a Congested Match Schedule.

Palucci Vieira, LH, Aquino, R, Lago-Peñas, C, Munhoz Martins, GH, Puggina, EF, and Barbieri, FA. Running performance in Brazilian professional football players during a congested match schedule. J Strength Cond Res 32(2): 313-325, 2018-The purpose of the study was to examine the influence of playing congested fixtures (2 matches a week) on running performance of Brazilian professional football players, pooled (all performance files regardless players' rotation between games) or individualized data treatment (including only files of athletes' who played pair(s) of noncongested-congested matches which occurred on the same week). Forty participants were observed 1-37 times during 59 official matches over 3 years. Global positioning system devices were used to compute total distance covered, maximal sprinting speed mean speed (VAVERAGE), and high-intensity activities (HIA: ≥15 km·h). Independent variables included match status (win, draw, and lose), location (home and away), opponent quality (weak and strong), competitive standard (national and state), team formation (4-4-2 and 4-3-3), and position (defender, midfielder, and forward). Student's t-test, effect sizes (d), and magnitude-based inferences were performed to detect differences between congested and noncongested fixtures for each independent factor. Overall, pooled and individualized data treatment revealed contrasting results. The first showed chances of positive outcomes playing congested matches (possibly to very likely; d = 0.09-0.55), for all variables, as using 4-4-2 and state tournament. Conversely, individualized data analysis revealed that during national leagues (possibly; d = 0.24) or forward position (likely; d = 0.70), the players presented reduced HIA when played congested than noncongested periods (p ≤ 0.05). Using 4-3-3 (d = 0.26) or when draw (d = 0.41), possibly lower HIA was also identified. Coaching staff should be aware of performance oscillations such as detrimental effects on HIA during congested periods.

Acute Effects of Active, Ballistic, Passive, and Proprioceptive Neuromuscular Facilitation Stretching on Sprint and Vertical Jump Performance in Trained Young Soccer Players.

Oliveira, LP, Vieira, LHP, Aquino, R, Manechini, JPV, Santiago, PRP, and Puggina, EF. Acute effects of active, ballistic, passive, and proprioceptive neuromuscular facilitation stretching on sprint and vertical jump performance in trained young soccer players. J Strength Cond Res 32(8): 2199-2208, 2018-The aim of this study was to compare the acute effects of active (AC), ballistic (BA), passive (PA), and proprioceptive neuromuscular facilitation (PNF) stretching methods on performance in vertical jumping, sit and reach, and sprinting in young soccer players. Twelve trained soccer players (17.67 ± 0.87 years) participated in the study. The jump height (H), peak power (PP), and relative power (RP) in the squat jump (SJ) and countermovement jump (CMJ), the range of motion (ROM), the rating of perceived exertion (RPE), and time (seconds) in 10-20-30-m sprints were evaluated. Significant differences (p < 0.05) in H were found in the comparisons between the PA and control (CO) condition for the SJ. For the CMJ, differences in H were observed between the PA and CO, and PNF with CO and BA, and in the PP between the PNF and CO, AC, and BA, as well as in the RP between the PNF and BA. Significant increases in ROM were found in the AC, BA, PA, and PNF compared with the CO. In relation to RPE, higher scores were reported in the PA and PNF conditions compared with the AC and BA. No significant differences were found in 10-20-30-m sprints. Therefore, the AC and BA methods can be used before vertical jump and sprint activities, with the aim of increasing flexibility. However, the PA and PNF methods should be avoided because of subsequent negative effects on vertical jump performance.

Multivariate Profiles of Selected versus Non-Selected Elite Youth Brazilian Soccer Players.

This study determined whether a multivariate profile more effectively discriminated selected than non-selected elite youth Brazilian soccer players. This examination was carried out on 66 youth soccer players (selected, n = 28, mean age 16.3 ± 0.1; non-selected, n = 38, mean age 16.7 ± 0.4) using objective instruments. Multivariate profiles were assessed through anthropometric characteristics, biological maturation, tactical-technical skills, and motor performance. The Student's t-test identified that selected players exhibited significantly higher values for height (t = 2.331, p = 0.02), lean body mass (t = 2.441, p = 0.01), and maturity offset (t = 4.559, p < 0.001), as well as performed better in declarative tactical knowledge (t = 10.484, p < 0.001), shooting (t = 2.188, p = 0.03), dribbling (t = 5.914, p < 0.001), speed - 30 m (t = 8.304, p < 0.001), countermovement jump (t = 2.718, p = 0.008), and peak power tests (t = 2.454, p = 0.01). Forward stepwise discriminant function analysis showed that declarative tactical knowledge, running speed -30 m, maturity offset, dribbling, height, and peak power correctly classified 97% of the selected players. These findings may have implications for a highly efficient selection process with objective measures of youth players in soccer clubs.