Impact of temperature on physical and cognitive performance in elite female football players during intermittent exercise.

There is limited research on female football players, especially related to their physical and cognitive performance under different climactic conditions. We analyzed the impact of a hot environmental temperature on physical performance and anticipation in elite female football players during a fatigue-inducing intermittent protocol. Elite female players (n = 21) performed the countermovement jump (CMJ) and responded to filmed sequences of offensive play under two distinct environmental temperatures (i.e., mild environment temperature- 20°C and 30% rh versus hot environment temperature- 38°C and 80% rh), interspersed by 1-week interval. Linear mixed models were used. CMJ performance declined following the intermittent protocol on both temperature conditions (p < 0.05). Moreover, there were significant main effects for protocol on CMJ speed (m/s) (p = 0.001; ηp 2 = 0.12), CMJ power (p = 0.002; ηp 2 = 0.11), and CMJ Heightmax (p = 0.002; ηp 2 = 0.12). After performing the intermittent protocol, exposure to a hot temperature caused a greater decline in anticipation accuracy (mild temperature = 64.41% vs. hot temperature = 53.44%; p < 0.001). Our study shows impaired performance in elite female football players following an intermittent protocol under hot compared with mild environmental conditions. We report decreased performance in both CMJ and anticipation performance under hotter conditions. The results reveal that exposure to hot temperatures had a negative effect on the accuracy of their anticipatory behaviors. We consider the implication of the work for research and training interventions.

Doxorubicin causes cachexia, sarcopenia, and frailty characteristics in mice.

While chemotherapy treatment can be lifesaving, it also has adverse effects that negatively impact the quality of life. To investigate the effects of doxorubicin chemotherapy on body weight loss, strength and muscle mass loss, and physical function impairments, all key markers of cachexia, sarcopenia, and frailty. Seventeen C57/BL/6 mice were allocated into groups. 1) Control (n = 7): mice were exposed to intraperitoneal (i.p.) injections of saline solution. 2) Dox (n = 10): mice were exposed to doxorubicin chemotherapy cycles (total dose of 18 mg/kg divided over 15 days). The body weight loss and decreased food intake were monitored to assess cachexia. To assess sarcopenia, we measured muscle strength loss using a traction method and evaluated muscle atrophy through histology of the gastrocnemius muscle. To evaluate physical function impairments and assess frailty, we employed the open field test to measure exploratory capacity. Doxorubicin administration led to the development of cachexia, as evidenced by a significant body weight loss (13%) and a substantial decrease in food intake (34%) over a 15-day period. Furthermore, 90% of the mice treated with doxorubicin exhibited sarcopenia, characterized by a 20% reduction in traction strength (p<0,05), a 10% decrease in muscle mass, and a 33% reduction in locomotor activity. Importantly, all mice subjected to doxorubicin treatment were considered frail based on the evaluation of their overall condition and functional impairments. The proposed model holds significant characteristics of human chemotherapy treatment and can be useful to understand the intricate relationship between chemotherapy, cachexia, sarcopenia, and frailty.

Dispositional greed and life satisfaction: the role of social comparison for well-being.

There is a lack of studies addressing the psychological mechanisms underlying the association between individual differences in greed and well-being. This study tested the relationship between dispositional greed, and satisfaction with life, as well as the moderating effect of social comparison orientation on this association (N = 373). As expected for hypothesis 1, we found that greed correlated negatively with satisfaction with life, and positively with social comparison orientation, even after controlling for individuals' mental health index (anxiety and depression), supporting the hypothesis 2. Further, the moderating effect of social comparison strengthened the relationship between high levels of dispositional greed and dissatisfaction with life, failing to support hypothesis 3. As such, individuals high on dispositional greed were less satisfied with life if they also showed lower (vs. medium level) levels of social comparison orientation. These findings add to the psychological literature on greed by showing that social comparison is not only positively related to it but can also be a vital mechanism for boosting psychological well-being.

A school-based physical activity intervention in primary school: effects on physical activity, sleep, aerobic fitness, and motor competence.

Objective: The "Super Quinas" project evaluated the effectiveness of an intervention program to improve physical activity, aerobic fitness, sleep, and motor competence on children in primary school. Methods: The experimental group (n = 19) enrolled in a 12-week intervention program (one more extra-curricular activity class of 60 min per week) compared to the CG (n = 19), all aged 9-10 years. Physical activity (PA) and sleep were measured by accelerometry, and aerobic fitness was measured by Children's Yo-Yo test (YYIR1C) during the 1st week (PRE), the 6th week (DUR), and the 12th week (POST) of the intervention program. Motor Competence in PRE and POST intervention was also assessed by the Motor Competence Assessment (MCA) instrument. Heart rate (HR, assessed using HR monitors), and enjoyment level were recorded during all intervention program classes. A linear mixed model analysis (i.e., within-subject analyses) was performed. Results: Comparing the EG and CG in DUR and POST, the EG spent ~18 min and ~ 34 min more time in moderate to vigorous physical activity (MVPA) per day (p < 0.001); had ~44 min and ~ 203 min less sedentary time per day (p < 0.001); performed more 44 and 128 m in the Children's Yo-Yo test compared to CG (p < 0.001) and slept more 17 and 114 min per night (p < 0.001). In POST motor competence was significantly better (27%) in the EG compared to CG (p < 0.001). The %HRmax during the extra-curricular classes ranged between 65 and 81% (i.e., light to moderate intensities), and the enjoyment between fun and great fun. Conclusion: Our findings suggest that adding one more extra-curricular activity class of 60 min per week for 12 weeks effectively increased the levels of physical activity, aerobic fitness, sleep duration, and motor competence in children aged 9-10 years.

Psychometric properties of the Brazilian-Portuguese Flow State Scale Short (FSS-BR-S).

"Flow experience" is a term used to describe the state of being fully immersed in what you are doing. The Flow State Scale (FSS-2) was developed to assess how people feel when they are in the flow state while participating in certain sports activities. The goal of this study was to obtain a short adapted version of the FSS-2 for the Brazilian-Portuguese language and for general activities (FSS-BR-S). To do this, we translated it both ways (forwards and backwards) and verified that the translation was accurate. Methods: After getting answers from 396 Brazilian participants, we performed (1) the construct validity of the FSS-BR-S and (2) the psychometric item quality analysis. The confirmatory factorial analysis shows that a FSS-BR-S factorial model is the best fit for the data (χ2 = 44.36, p = .023, df = 27, χ2/df = 1.64, CFI = 0.99, TLI = 0.98, and RMSEA = 0.04). Reliability tests done in this structure show that the FSS-BR-S (which only has nine items) has good internal consistency. The item quality analysis reveals that its difficulty and differentiating parameters are good for estimating the overall flow state. The test information curve for the short version demonstrates that it is very useful for estimating the flow states of each disposition. Discussion and Conclusions: Based on these findings, we can conclude that the FSS-BR-S has demonstrated sufficient validity to be used with Brazilians.

Sleep duration is associated with overnight changes in perceived fatigue in elite women soccer players.

The current study aimed to describe sleep habits and analyze the associations between sleep indices, changes in perceived fatigue (Δ Fatigue) and external training load measures in women soccer players during a 7-day training camp. Sixteen elite women soccer players (age: 25.4 ± 3.6 years; mean ± SD) from the Portuguese Women's National Team participated in the study. Sleep indices (sleep duration and efficiency) were measured using a wrist-worn accelerometer. External training loads measures were measured using GPS devices. Players also reported perceived fatigue using a Likert scale (1 - very, very low to 7 - very, very high) before and immediately after sleep. Players' within-subject coefficient of variation for sleep duration was 5.6%, and 4.6% for sleep efficiency. Individually, 8 players (50%) slept less than 7 h per night throughout the training camp, and the same number of athletes had a sleep efficiency lower than 85%. Similar values (p<0.05) were measured for sleep duration and efficiency between training and match days. A moderate negative within-subjects correlation was found between Δ Fatigue and sleep duration (adjusted for pre-sleep fatigue) [r = -0.32; 95% Confidence Interval (-0.51 - -0.08); p = 0.04]. These findings reinforce the importance of sleep in the recovery process of elite women soccer players, showing that more sleep may help to attenuate fatigue.

Association between childhood anthropometric indicators and bone mineral density in adulthood / Associação entre indicadores antropométricos na infância e densidade mineral óssea na idade adulta

ABSTRACT Objective: This study aimed to verify the association between childhood anthropometric indicators and areal bone mineral density (aBMD) in adulthood. Methods: Repeated measures of 137 subjects (68 females) were obtained in childhood (9.2±1.5 years of age) and adulthood (22.3±1.7 years of age). aBMD (g/cm2) was assessed for whole body, lumbar spine, upper and lower limbs, and femoral neck in adulthood using dual-energy X-ray absorptiometry. Anthropometric measurements of body weight (BW), height, triceps and subscapular skinfolds were obtained in childhood. The anthropometric indicators used were BW, body mass index (BMI), and sum of skinfolds (ΣSF). Simple linear regression was used to assess the association between childhood anthropometric indicators and aBMD in adulthood, controlled by chronological age and stratified by sex, with 5% statistical significance. Results: In females, multiple associations were observed between anthropometric indicators and aBMD, with higher coefficients for BMI (β=0.020; R2=0.20; p<0.01 for right femoral neck to β=0.008; R2=0.16; p<0.01 for upper limbs), followed by BW (β=0.003; R2=0.21; p<0.01 for upper limbs to β=0.008; R2=0.20; p<0.01 for right femoral neck) and ΣSF (β=0.001; R2=0.06; p<0.01 for upper limbs to β=0.005; R2=0.12; p<0.01 for right femoral neck). In males, associations were observed only for the lumbar spine region (β=0.016; R2=0.09 for BMI to β=0.004; R2=0.06; p<0.01 for ΣSF). Conclusions: Anthropometric indicators of childhood proved to be sensitive predictors of aBMD in adulthood, especially in females. BMI indicated a greater association with aBMD in both sexes.

RESUMO Objetivo: O objetivo do estudo foi verificar a associação entre os indicadores antropométricos da infância com a área da densidade mineral óssea (aDMO) na idade adulta. Métodos: Medidas repetidas de 137 sujeitos (68 do sexo feminino) foram obtidos na infância (9,2±1,5 anos de idade) e idade adulta (22,3±1,7 anos de idade). A aDMO (g/cm2) foi avaliada para todo o corpo, coluna lombar, membros superiores e inferiores e colo do fêmur na idade adulta usando a absorciometria radiológica de dupla energia (DXA). Medidas antropométricas de peso corporal, estatura e dobras cutâneas das regiões tricipital e subescapular foram obtidas na infância. Os indicadores antropométricos utilizados para as análises foram o peso corporal (PC), o índice de massa corporal (IMC) e o somatório de dobras cutâneas (ΣDC). Regressão linear simples controlada pela idade e estratificada por sexo foi empregada para avaliar a associação entre os indicadores antropométricos do período da infância na aDMO na idade adulta, com significância estatística de 5%. Resultados: No sexo feminino, múltiplas associações foram observadas entre os indicadores antropométricos e a aDMO, com maiores coeficientes para IMC (β=0,020; R2=0,20; p<0.01 para colo do fêmur direito a β=0,008; R2=0,16; p<0,01 para membros superiores), seguido da PC (β=0,003; r2=0,21; p<0,01 para membros superiores a β=0,008; r2=0,20; p<0,01 para colo do fêmur direito) e ΣDC (β=0,001; R2=0,06; p<0,01 para membros superiores a β=0,005; R2=0,12; p<0,01 para colo do fêmur direito). No sexo masculino, associações ocorreram apenas na região da coluna (β=0,016; R2=0,09 para IMC a β=0,004; R2=0,06; p<0,01 para ΣDC). Conclusões: Indicadores antropométricos da infância mostraram ser sensíveis preditores da aDMO na idade adulta, especialmente no sexo feminino. O IMC indicou maior associação com a aDMO em ambos os sexos.

Simulated Soccer Game Protocols: A Systematic Review on Validated Protocols That Represent the Demands of the Game.

ABSTRACT: Brito, P, Costa, J, Figueiredo, P, and Brito, J. Simulated soccer game protocols: A systematic review on validated protocols that represent the demands of the game. J Strength Cond Res 38(1): 192-205, 2024-Several laboratory and field testing protocols have been developed attempting to simulate the activity pattern and physiological demands of soccer. In the present systematic review, we aimed to analyze and discuss the appropriateness, strengths, and limitations of soccer-specific simulated tests. A systematic review of the literature was conducted based on the PRISMA guidelines. Studies conducted in soccer, simulated soccer match tests, and validated simulation protocols performed on-the-field or on a treadmill were considered. No sex restriction was applied, and age >18 years (i.e., adults) was considered. At least 1 outcome measure (e.g., neuromuscular performance, external load, internal load, or psychometric state) of post-simulated-match test or protocol had to be reported. Within the 14 studies included, the average methodological quality of the included articles was 0.61 ± 0.09 (mean ± SD) of 1. Overall, 9 validated protocols were identified. In the protocols, only amateur, university, or semiprofessional soccer players were analyzed. Only one study evaluated female soccer players. None of the studies evaluated the effect on performance over the 2-3 days after the protocol. Accelerations and decelerations, and changes in direction typically present in a game have not been clearly described in any protocol. Future research should address this issue and validate soccer-specific protocols in women.

Effects of "Football and Nutrition for Health" program on body composition, physical fitness, eating behaviours, nutritional knowledge, and psychological status among 7 to 10 years school children.

Introduction: Noncommunicable diseases and obesity are between the major health threat due to consumption of unhealthy foods and limited time spent on physical activities, a situation of particular concern among children. Since children spend most of their time at school, this study intends to investigate the effect of a school intervention program, which combines recreational football and nutrition education, on body composition, physical fitness, physical activity, blood pressure and heart rate, eating behaviours, nutritional knowledge, and psychological status in elementary school children. Methods: A total of 67 children, between 7 and 10 years old, were allocated into three groups: the Football Group (FG) which held 2 weekly sessions of 60 min of recreational football, the Nutrition and Football Group (NFG) which held 2 sessions per week of 60 min of recreational football plus 60 min of nutritional education and the Control Group (CG) which maintained its usual curriculum. The intervention lasted 12 weeks. All measurements were collected before and after the intervention. Results: Intervention groups significantly (p < 0.05) improved BMI Z-score, rest heart rate, horizontal jump and shuttle test, physical activity level, and psychosocial health. The NFG group significantly decreased (p < 0.05) waist-to-height ratio and blood pressure, and significantly increased (p < 0.05) nutritional knowledge, fruit, and fish consumption. While FG significantly decreased (p < 0.05) the percentage of fat mass and significantly increased (p < 0.05) muscle mass and performance in the 20 m sprint. Discussion: The results have shown to improve nutritional status, explosive strength, aerobic and neuromuscular fitness, as well as increase the level of physical activity. The nutritional education sessions contributed to increase nutritional knowledge and to improve the consumption of healthy food groups in a ludic-educational way. The "Football and Nutrition for Health" program was able to induce short-term improvements in several health markers, highlighting the role of the school curriculum in children's health.

Time Reallocations From Sedentary Behavior to Physical Activity and Cardiovascular Risk Factors in Children and Adolescents: A Systematic Review.

BACKGROUND: Recent statistical approaches have allowed consideration of the integrated relationships between sedentary behavior (SB) and physical activity (PA) with different health outcomes. The present paper aimed to systematically review the literature and synthesize evidence about associations between hypothetical reallocations from SB to different PA intensities and cardiovascular risk factors in youth. METHODS: A systematic search of 8 databases was performed. Observational studies with a population of children and/or adolescents and based on statistical analysis that investigated the associations between time reallocations from SB to PA and cardiovascular risk factors were included. RESULTS: Twenty-eight studies met the inclusion criteria. Level of evidence (derived from cross-sectional studies) indicated that the reallocation from SB to moderate to vigorous PA was beneficially associated with adiposity, cardiorespiratory fitness, and cardiometabolic biomarkers in youth. Reallocation from SB to light PA was not associated with the analyzed outcomes. Associations derived from longitudinal studies were mostly inconclusive. CONCLUSION: Cardiovascular risk factors could be improved by increasing moderate to vigorous PA at the expense of time spent in SB in pediatric populations. Prospective studies or studies investigating the effects of reallocating sedentary bouts to PA are needed.

Exploring Gut Microbiota and the Influence of Physical Activity Interventions on Overweight and Obese Children and Adolescents: A Systematic Review.

The recognition that the gut microbiota of obese children differs from lean children has grown, and some studies suggest that physical activity positively influences the gut microbiota. This systematic review explores the changes in the gut microbiota composition of obese and non-obese children and adolescents and provides an understanding of the effects of physical activity interventions in modulating their microbiota. The PRISMA protocol was used across PubMed, Scopus, and Web of Science. Overall, twenty-four research papers were included in accordance with the chosen inclusion and exclusion criteria, eighteen studies compared the gut microbiota of obese and normal-weight children and adolescents, and six studies explored the effect of physical activity interventions on the gut microbiota. The analysis indicated that obese gut microbiota is reduced in Bacteroidetes, Bifidobacterium and alpha diversity but enriched in Proteobacteria and Lactobacillus. Interventions with physical activity seem to improve the alpha diversity and beneficial bacteria linked to body weight loss in children and adolescents. The gut microbiota of obese children exhibited a remarkably individual variation. More interventions are needed to clearly and accurately explore the relationships between child obesity, gut microbiota, and physical activity and to develop approaches to decrease the incidence of paediatric obesity.

Efeitos da COVID-19 no bem e mal-estar psicológico de estudantes universitários(as) migrantes / Efectos del Covid-19 en la vida universitaria de los migrantes: análisis de impactos psicosociales / Effects of Covid-19 on Migrant University Life: Analyzing Psychosocial Impacts

O cenário imposto pela pandemia da Covid-19 e a implementação do modelo remoto de educação implicaram em mudanças nos padrões de deslocamento de estudantes universitários(as) que antes necessitavam realizar a mobilidade pendular entre municípios para ter acesso ao ensino superior. Para além das modificações no processo migratório, a pandemia trouxe outros agravos, como a vulnerabilidade à saúde mental e física. Nesse sentido, o presente estudo buscou analisar os efeitos da Covid-19 no bem e mal-estar psicológico de estudantes universitários(as) migrantes segundo marcadores sociais. Para tanto, ainda que a coleta tenha sido realizada no período pandêmico, contou-se com a participação de 202 estudantes que realizavam mobilidade pendular em período antes da pandemia, ou que passaram a residir em outro município a fim de ter acesso ao ensino superior. Os(as) participantes foram convidados(as) a responder a um questionário eletrônico contendo as escalas DASS-21 e Perma-profiler, além de algumas questões socioeconômicas e discursivas. Os dados quantitativos foram analisados por meio dos softwares jASP e R. Em seguida, foram realizadas as análises lexicais com os dados qualitativos, através do software Iramuteq. Os resultados obtidos permitiram constatar que a maioria dos participantes apresentou níveis considerados severos de depressão, ansiedade e estresse, assim como níveis considerados medianos de bem-estar. Pode-se destacar ainda uma maior percepção de mal-estar psicológico em grupos específicos quando consideradas variáveis socioeconômicas como raça, gênero, orientação sexual e classe social.

El escenario impuesto por la pandemia de COVID-19 y la implementación del modelo de educación remota provocaron cambios en los patrones de desplazamiento de los(as) estudiantes universitarios(as) que antes necesitaban desplazarse entre municipios para acceder a la educación superior. Además de los cambios en el proceso migratorio, la pandemia trajo otros problemas, como la vulnerabilidad en la salud física y mental. En este sentido, el presente estudio buscó analizar los efectos de la COVID-19 en el bienestar y malestar psicológico de estudiantes universitarios(as) migrantes según marcadores sociales. Para ello, si bien la colecta se realizó durante el periodo de pandemia, participaron 202 estudiantes que se desplazaban antes de la pandemia, o que se trasladaron a otro municipio para poder acceder a la educación superior. Se invitó a los(as) participantes a responder a un cuestionario electrónico que contenía las escalas DASS-21 y PERMA-profiler, además de algunas preguntas socioeconómicas y discursivas. Los datos cuantitativos fueron analizados mediante el software JASP y R. A continuación, se realizaron análisis léxicos con los datos cualitativos, utilizando el software Iramuteq. Los resultados obtenidos mostraron que la mayoría de los participantes presentaron niveles considerados severos de depresión, ansiedad y estrés, así como niveles considerados medios de bienestar. También es posible destacar una mayor percepción de malestar psicológico en grupos específicos al considerar variables socioeconómicas como raza, género, orientación sexual y clase social.

The scenario imposed by the pandemic of Covid-19, and the implementation of remote learning implied changes in the displacement patterns of university students who previously needed to carry out the commuting migration between municipalities to have access to higher education. In addition to changes in the migratory process, the pandemic brought other health problems, such as vulnerability to mental disorders and physical health problems. As such, the present study sought to analyze the effects of Covid-19 on the psychological well-being and ill-being of migrant university students according to social markers. To this end, 202 students participated. These students carried out commuting in the period before the pandemic, or moved to another municipality in order to have access to higher education. The collection of data was carried out during the pandemic period. Participants were invited to answer an electronic questionnaire containing the DASS-21 and Perma-profiler scales, in addition to some socioeconomic and discursive questions. Quantitative data were analyzed using jASP and R software. Then, lexical analysis were performed with qualitative data, using the Iramuteq software. The results obtained showed that most participants had levels considered severe of depression, anxiety and stress, and levels considered median of well-being. It is also possible to highlight a greater perception of psychological ill-being in specific groups when so- cioeconomic variables are considered such as race, gender, sexual orientation and social class.

José Luis Arteta y Aljibez (1912-1957), un patólogo excepcional en la esfera de Gregorio Marañón, Carlos Jiménez Díaz y Pío Baroja / José Luis Arteta y Aljibez (1912-1957), an exceptional pathologist in the steps of Gregorio Marañón, Carlos Jiménez Díaz and Pío Baroja

José Luis Arteta, fue uno de los últimos discípulos de Cajal. Él encarna como pocos la transición entre la brillante escuela neurohistológica española, con el inicio de la anatomía patológica diagnóstica de ámbito hospitalario asistencial. Esa transición ocurre durante la difícil posguerra en la década de los cuarenta e inicio de los cincuenta del siglo XX, hasta culminar con la fundación de la Sociedad Española de Anatomía Patológica en 1959. Como muchos de los patólogos de su generación, dominaba la práctica de las autopsias clínicas, pero en el Hospital Provincial de Madrid tuvo ocasión de desarrollar el diagnóstico biópsico de la mano del clínico más brillante de su generación Carlos Jiménez Díaz, al tiempo que mantenía una notable actividad investigadora en el Instituto Cajal y a través de su estrecha colaboración con Gregorio Marañón. Además de médico y patólogo, Arteta era un humanista, de vasta cultura, que también pudo desarrollar por su entrañable amistad con Pío Baroja. Sobre su prematura muerte a los 45 años por poliomielitis, queda una sombra de misterio acerca de si se trató de una infección ambiental o una inoculación accidental durante sus investigaciones sobre este virus.(AU)

José Luis Arteta, was one of Cajal's last students at the outstanding institute of neurohistology. His career highlights a time of transition in Spanish pathology during the difficult years between the 1940s and the early 1950s, following the Spanish civil war. Diagnostic pathology was beginning to take place within the hospital setting and eventually, in 1959, the Spanish Society of Pathology (SEAP) was founded. Like many of his peers, he was expert in clinical autopsies, but he also had the opportunity, in the Provincial Hospital in Madrid, to develop skills in biopsy diagnosis under the tutelage of Carlos Jimenez Díaz, the most brilliant clinician of the time. He continued his research at the Cajal Institute and in collaboration with Gregorio Marañón. However, not only was Arteta a notable physician and pathologist, he was also a cultured humanist and close friend of Pío Baroja. His premature death at age 45 from poliomyelitis remains somewhat of a mystery: was it caused by an environmental infection or an accidental inoculation during his research on the virus?.(AU)

Advancing school dropout early warning systems: the IAFREE relational model for identifying at-risk students.

Introduction: There is a global effort to address the school dropout phenomenon. The urgency to act on it comes from the harmful evidence that school dropout has on societal and individual levels. Early Warning Systems (EWS) for school dropout at-risk student identification have been developed to anticipate and help schools have a better chance of acting on it. However, several studies point to a doubt that Correct EWS may come too late because they use only publicly available and general student and school information. We hypothesize that having a tool to assess more subjective and inter-relational factors would help anticipate where and when to act to prevent school dropout. This study aimed to develop a multidimensional measure for assessing relational factors for predicting school dropout (SD) risk in the Brazilian context. Methods: We performed several procedures, including (a) the specialized literature review, (b) the item development of the Relational Factors for the Risk of School Dropout Scale (IAFREE in Portuguese), (c) the content validity analysis, (d) a pilot study, and (e) the administration of the IAFREE to a large Brazilian sample of high school and middle school students (N = 15,924). Results: After the theoretical steps, we found content validity for five relational dimensions for SD (Student-School, Student-School Professionals, Student-Family, Student-Community, and Student-Student) that include 12 facets of risk factors. At the empirical stage, confirmatory analysis corroborated the proposed theoretical model with 12 first-order risk factors and 5 s-order dimensions (36 items). Further, through the Item Response Theory analysis, we assessed the individual item parameters of the items, providing a brief measure without losing psychometric quality (IAFREE-12). Discussion: We discuss how this model may fill gaps in Correct EWS models and how to advance it. The IAFREE is a good measure for scholars investigating the risk of SD. These results are important for implementing an early warning system for SD that looks into the complexity of the school dropout phenomenon.

Effects of Physical Activity and Nutrition Education on the Gut Microbiota in Overweight and Obese Children.

Childhood obesity continues to represent a growing challenge, and it has been associated with gut microbiota dysbiosis. This study examines the gut microbiota composition in overweight and obese school children and assesses whether a 12-week multidisciplinary intervention can induce changes in the gut microbiota. The intervention, which combined recreational football and nutritional education, was implemented among 15 school children, aged 7-10 years, with a Body Mass Index ≥ 85th percentile. The children were assigned into two groups: Football Group (n = 9) and Nutrition and Football Group (n = 6). Faecal samples were collected at the beginning and end of the program and analysed by sequencing the 16S rRNA gene. Over the intervention, a significant decrease was found collectively for Bifidobacterium genera (p = 0.011) and for Roseburia genera in the Football Group (p = 0.021). The relative abundance of Roseburia (p = 0.002) and Roseburia faecis (p = 0.009) was negatively correlated with moderate to vigorous physical activity (MVPA), while Prevotella copri was positively correlated with MVPA (p = 0.010) and with the daily intake of protein (p = 0.008). Our findings suggest that a multidisciplinary intervention was capable of inducing limited but significant positive changes in the gut microbiota composition in overweight and obese school children.

Reliability of Maximal Strength and Peak Rate of Force Development in a Portable Nordic Hamstrings Exercise Device.

The Nordic hamstring exercise (NHE) is a very popular exercise used to improve eccentric strength and prevent injuries. The aim of this investigation was to assess the reliability of a portable dynamometer that measures maximal strength (MS) and rate of force development (RFD) during the NHE. Seventeen physically active participants (34.8 ± 4.1 years; n = 2 women and n = 15 men) participated. Measurements occurred on two different days separated by 48-72 h. Test-retest reliability was calculated for bilateral MS and RFD. No significant test-retest differences were observed in NHE (test-retest [95% CI, confidence interval]) for MS [-19.2 N (-67.8; 29.4); p = 0.42] and RFD [-70.4 N·s-1 (-178.4; 37.8); p = 0.19]. MS showed high reliability (intraclass correlation coefficient [ICC] [95% CI], =0.93 [0.80-0.97] and large within-subject correlation between test and retest [r = 0.88 (0.68; 0.95)]. RFD displayed good reliability [ICC = 0.76 (0.35; 0.91)] and moderate within-subject correlation between test and retest [r = 0.63 (0.22; 0.85)]. Bilateral MS and RFD displayed a coefficient of variation of 3.4% and 4.6%, respectively, between tests. The standard error of measurement and the minimal detectable change for MS was 44.6 arbitrary units (a.u.) and 123.6 a.u., and 104.6 a.u. and 290.0 a.u. for peak RFD. This study shows that MS and RFD can be measured for NHE using a portable dynamometer. However, not all exercises are suitable to apply to determine RFD, so caution must be taken when analyzing RFD during NHE.

Effects of dietary supplements on athletic performance in elite soccer players: a systematic review.

Dietary supplements are widely used among athletes, and soccer players are no exception. Nevertheless, evidence supporting the use of dietary supplements aiming to enhance performance in soccer is somewhat contradictory, scarce, or even nonexistent. Thus, the present study aimed to systematically review and synthesize the effects of dietary supplements on athletic performance (e.g. distance covered, sprinting, jump performance) in elite soccer players. Studies enrolling highly trained, elite, and world-class soccer players using dietary supplements were searched in MEDLINE/PubMed, Web of Science, Scopus, and EBSCO databases in June 2022. In total, 1043 studies were identified, and 18 met the eligibility criteria. The studies evaluated the impacts on athletic performance of several dietary supplements, including caffeine, creatine, protein, beverages with carbohydrates and electrolytes, tart cherry juice, nitrate-rich beetroot juice, sodium bicarbonate with minerals, yohimbine, and a proprietary nutraceutical blend. Caffeine supplementation in doses between 3 and 6 mg/kg of body mass may improve jump height and sprint ability, particularly in female players, but individual response to caffeine must be considered. Creatine may improve sprint, agility, and in female players, jump performance. Protein supplementation can improve sprint and jump performance between matches, especially if protein ingested from food is not up to recommendations. Beverages containing carbohydrates and electrolytes can be used as part of the strategies to achieve carbohydrate intake during training and match-days but used alone do not benefit athletic performance. Tart cherry juice might be useful for maintaining athletic performance after matches that produce higher force loss and exercise-induced muscle damage, although polyphenols from the diet might attenuate the effects of tart cherry supplementation. Nitrate-rich beetroot concentrate can attenuate performance decrease in the days following matches. Further investigation with sodium bicarbonate alone is necessary, as supplementation protocols with elite players included other substances. Finally, the available data does not support yohimbine supplementation or the use of Resurgex Plus® to improve athletic performance in elite soccer players. Still, more well-designed research with elite soccer players is needed to improve support and advice regarding the use of dietary supplements for athletic performance enhancement.

The Impact of Sleep Interventions on Athletic Performance: A Systematic Review.

BACKGROUND: Sleep is essential for maximal performance in the athletic population. Despite that, the sport context has many factors that can negatively influence athletes' sleep and subsequent recovery. OBJECTIVES: The purpose of this systematic review was to synthesize the most recent literature regarding sleep interventions aimed at improving sleep and subsequent performance in athletes. METHODS: The present systematic review was conducted based on the PRISMA guidelines and the PICOS approach. The search was conducted in May 2022 using the electronic database PubMed, SPORTDiscus via EBSCOhost, and Web of Science. Once extracted, studies were included if they met the following criteria: (1) participants were athletes of individual or team sports; (2) implemented an intervention aimed at improving sleep; (3) measured at least one objective performance/recovery outcome; and (4) reported the relationship between sleep and performance. RESULTS: The search returned 1584 records. Following the screening, a total of 25 studies met our inclusion criteria. All the included articles were intervention studies published between 2011 and 2021. The included studies implemented various sleep interventions, such as sleep hygiene, naps, sleep extension, light manipulation, cold water immersion, mindfulness, or a combination of two or more strategies. Sleep extension and naps were the most representative and most effective strategies to improve sleep and performance. Mindfulness and light manipulation demonstrated promising results, but more studies are needed to confirm these findings. Sleep hygiene, removing electronic devices at night, and cold water immersion had no effects on sleep and subsequent performance/recovery, but these results are based on a few studies only. CONCLUSION: While acknowledging the limited amount of high-quality evidence reviewed, it appears that increasing sleep duration at night or through napping was the most effective interventions to improve physical and/or cognitive performance. Protocol Registration This protocol was registered in the International Platform of Registered Systematic Review and Meta-Analysis Protocols (INPLASY) on May 11, 2022, with the registration number INPLASY202250069.

Maturity-associated variation in the body size, physical fitness, technical efficiency, and network-based centrality measures in young soccer players.

This study aimed to observe the relationships between the maturity status on the network-based centrality measures of young athletes in small-sided soccer games (SSG). The study included 81 male players (14.4 ± 1.1 years). Measurements included height, sitting height, body mass, and bone age (TW3 method). The applied protocols were the following: Countermovement Jump (CMJ), Yo-Yo Intermittent Recovery Test Level 1 (YYIRT1), Repeated Sprints Ability (RSA), observational analysis of techniques, and interactions performed by players in SSG. The relationship between the set of evaluated variables within each maturity status was obtained from the correlational analysis of networks (P < 0.05). The maturity status explained a significant portion of the variance in body mass (η2 = 0.37), height (η2 = 0.30), sitting height (η2 = 0.30), and performance on the YYIRT1 (η2 = 0.08), CMJ (η2 = 0.14), and RSA (η2 = 0.13). No effect of maturity status on network-based centrality measures of young athletes was identified (P > 0.05). For the late maturity group, there was a correlation between the degree of centrality and physical growth indicators (rmean = 0.88). For players with maturation "on time", physical growth indicators relate to the degree of prestige (rmean = 0.36). It is concluded that body size and bone age impact how late and on-time maturity groups interact within the match.