Relationship between relative age measured through decimal age, physical variables and anthropometry in elite youth soccer players.

INTRODUCTION: Age differences between athletes born in the same year, as well as an over-representation of older players, are known as the Relative Age Effect (RAE). Players born at the beginning of the selection year have a physical and anthropometric advantage over their younger peers. Experts keep looking for new prediction variables for talent identification. OBJECTIVES: The aim of the study is to correlate anthropometric, strength and power variables with the relative age (RA) and the level of the teams in which players played in each age category. METHODS: All players (N = 366) from an elite soccer academy of a Spanish club volunteered to participate in the study (U23-U10). RESULTS: There was a significant correlation between the RA of the players and the level of the team in which they played in each age category but no correlation between trimester of birth and level of the team. We found significant correlations between the players' physical capacities, anthropometry, RA and the level of the team in which they played for the same age category, mainly from U16 to U10. U23 did not show any correlation between RA and physical or anthropometric variables. CONCLUSION: Coaches should be cautious of choosing players based only on anthropometric or physical attributes.

Effects of different phenylcapsaicin doses on neuromuscular activity and mechanical performance in trained male subjects: a randomized, triple-blinded, crossover, placebo-controlled trial.

Objective: This study aimed to examine the effects of phenylcapsaicin (PC) supplementation on strength performance and neuromuscular activity in young trained male subjects. Materials and methods: A total of 25 trained subjects [full-squat (SQ) one repetition maximum (1RM) = 125.6 ± 21.0 kg] were enrolled in this randomized, triple-blinded, crossover, placebo-controlled trial. The subjects performed a first session and a post-24 h session for each condition. In the first session, the subjects ingested a high dose of PC (HD, 2.5 mg), a low dose (LD, 0.625 mg), or a placebo (PLA). Their performance in SQ was assessed under a 3% × 8 × 70% 1RM protocol in the first session. Their performances in countermovement jump (CMJ), SQ with 60% 1RM, and isometric squat were measured before and after the SQ protocol in both sessions. The neural activity of the vastus lateralis (VL) and vastus medialis (VM) was recorded via surface electromyography (EMG) and averaged in both sessions. Results: Significant differences between the conditions were reported for lifting velocity, velocity loss, and the 60% load in dynamic SQ (p range = 0.02-0.04). Electrical changes were not identified for any outcome, although neural activity changed across time (p range ≤0.001-0.006). A significant condition × time effect was observed in CMJ compared to PLA (p ≤0.001) and LD (p ≤0.001). Intra-set analyses revealed higher velocities in HD compared to those in LD (p = 0.01) and PLA (p range = 0.004-0.008). Conclusion: Therefore, PC may improve the strength performance and attenuate the mechanical fatigue induced by resistance training in SQ and CMJ exercises.

Impact of a Serious Game (#RedPingüiNO) to Reduce Facial Self-Touches and Prevent Exposure to Pathogens Transmitted via Hands: Quasi-Experimental Intervention.

BACKGROUND: After the COVID-19 pandemic, society has become more aware of the importance of some basic hygienic habits to avoid exposure to pathogens transmitted via hands. Given that a high frequency of touching mucous membranes can lead to a high risk of infection, it is essential to establish strategies to reduce this behavior as a preventive measure against contagion. This risk can be extrapolated to a multitude of health scenarios and transmission of many infectious diseases. #RedPingüiNO was designed as an intervention to prevent the transmission of SARS-CoV-2 and other pathogens through the reduction of facial self-touches by thoughtfully engaging participants in a serious game. OBJECTIVE: Facial self-touches should be understood as behaviors of limited control and awareness, used to regulate situations of cognitive and emotional demands, or as part of nonverbal communication. The objective of this study was to ensure that participants become aware of and reduce these behaviors through a game of self-perception. METHODS: The quasi-experimental intervention was applied to 103 healthy university students selected by convenience sampling and put into practice for 2 weeks, with 1 control group (n=24, 23.3%) and 2 experimental groups (experimental group with no additional social reinforcement interventions: n=36, 35%; experimental group with additional social reinforcement interventions: n=43, 41.7%). The objective was to improve knowledge and perception and reduce facial self-touches to prevent exposure to pathogens transmitted via hands not only in health multihazard scenarios but also in ordinary circumstances. The ad hoc instrument used to analyze the experience consisted of 43 items and was valid and reliable for the purpose of this study. The items were divided into 5 blocks extracted from the theoretical framework: sociological issues (1-5); hygiene habits (6-13); risk awareness (14-19); strategies for not touching the face (20-26); and questions after the intervention (27-42), designed as a postintervention tool assessing the game experience. Validation of the content was achieved through assessment by 12 expert referees. External validation was performed using a test-retest procedure, and reliability was verified using the Spearman correlation. RESULTS: The results of the ad hoc questionnaire, which were analyzed using the Wilcoxon signed-rank test and McNemar index to identify significant differences between test and retest for a 95% CI, showed that facial self-touches were reduced (item 20, P<.001; item 26, P=.04), and awareness of this spontaneous behavior and its triggers increased (item 15; P=.007). The results were reinforced by qualitative findings from the daily logs. CONCLUSIONS: The intervention exhibited a greater effect from sharing the game, with interactions between people; however, in both cases, it was helpful in reducing facial self-touches. In summary, this game is suitable for reducing facial self-touches, and owing to its free availability and design, it can be adapted to various contexts.

Effects of different phenylcapsaicin doses on resistance training performance, muscle damage, protein breakdown, metabolic response, ratings of perceived exertion, and recovery: a randomized, triple-blinded, placebo-controlled, crossover trial.

BACKGROUND: The aim of this study was to explore the effects of a low dose (LD) of 0.625 mg and a high dose (HD) of 2.5 mg of phenylcapsaicin (PC) on full squat (SQ) performance, active muscle (RPE-AM) and overall body (RPE-OB) ratings of perceived exertion, muscle damage, protein breakdown, metabolic response, and 24-h recovery in comparison to placebo (PLA). METHOD: Twenty-five resistance-trained males (age = 21.00 ± 2.15 years, SQ 1-repetition maximum [1RM] normalized = 1.66 ± 0.22 kg) were enrolled in this randomized, triple-blinded, placebo-controlled, crossover trial. Participants completed 2 weekly sessions per condition (LD, HD, and PLA). The first session consisted of pre-blood testing of lactate, urea, and aspartate aminotransferases (AST) and 2 SQ repetitions with 60% 1RM followed by the resistance exercise protocol, which consisted of SQ sets of 3 × 8 × 70% 1RM monitoring lifting velocity. RPE-OB and RPE-AM were assessed after each set. After the first session, 2 SQ repetitions with 60% 1RM were performed, and blood lactate and urea posttests were collected. After 24 h, AST posttest and 1 × 2 × 60% 1RM were determined as biochemical and mechanical fatigue outcomes. RESULTS: HD reported significant differences for RPE-AM, AST, and SQ performance compared to LD and PLA. Post-hoc analyses revealed that HD attained faster velocities in SQ than LD (p = 0.008). HD induced a lower RPE-AM when compared with LD (p = 0.02) and PLA (p = 0.004). PLA resulted in higher AST concentrations at 24-h post than HD (p = 0.02). No significant differences were observed for the rest of the comparisons. CONCLUSIONS: This study suggests that PC may favorably influence SQ performance, RPE-AM, and muscle damage compared to PLA. However, HD exhibited most of the biochemical and mechanical anti-fatigue effects instead of LD.

Workloads of Different Soccer-Specific Drills in Professional Players.

Soccer is a predominantly tactical sport and, therefore, tactical training has become the most widely used strategy to improve players' performance. The objective of the present study was to assess the workload of soccer-specific drills in professional players over a two-season period in an established context. GPS technology was used to record the data. One hundred and thirty-two (n = 132) soccer-specific drills were studied and grouped by categories. The individual demands of each task were related to the individual competitive profile of each player. The level of physical demand was significantly different in relation to the specific soccer drills analysed. Total distance covered, high-speed running, and the total number of high accelerations and decelerations were significantly higher in competition than in drills used for training sessions (p < .001). The Large-Sided Games (LSG), Big-Position Games (BPG) and Position Games (PG) showed higher maximum running speed values than the rest of the exercises (p < .01). The sum of high accelerations and decelerations values was greater in the Small-Sided Games (SSG) than in BPG (p < .001), Small-Position Games (SPG) (p < .001) and Physical-Technical Circuits (PTC) (p < .001). Significant differences were observed in the exercises analysed according to the player's position. The current findings provide a detailed description of conditional demands placed on soccer players in different soccer-specific drills during training sessions, in a professional soccer context and according to their playing position, which may be helpful in the development of individualized training programs in other contexts.

The Physiological Effects of Face Masks During Exercise Worn Due to COVID-19: A Systematic Review.

CONTEXT: Use of face masks in sport has been a particularly complex issue during the COVID-19 pandemic. OBJECTIVES: A systematic review to examine the physiological effects the different types of masks have on healthy adults when doing physical exercise. DATA SOURCES: PubMed, SPORTDiscus, Scopus, and Litcovid were searched up to March 20, 2021, following the PRISMA model. Articles published in the last 5 years with healthy adults. STUDY SELECTION: A total of 633 studies related to the use of masks during physical exercise were found, of which 8 articles met the criteria to be included. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 2. DATA EXTRACTION: The search process and the review of the articles were carried out by independent expert researchers. The risk of bias and the methodological quality of the different studies included in the systematic review were calculated following the Cochrane criteria using an adaptation for random cross-studies. Once the information was properly structured, the results were extracted, and the findings of the study analyzed. RESULTS: There were significant changes in the following physiological variables when engaging in physical exercise using masks: 25% in the heart rate and dyspnea, 37.5% in the rating of perceived exertion, 50% in the pulmonary variables, and 37.5% in discomfort. The oxygen saturation, blood pressure, systolic blood pressure, diastolic blood pressure, and the concentration of blood lactate did not present any significant effect in this study. CONCLUSION: The usage of masks by a healthy adult population during the performance of physical exercise has shown minimal effects with regard to physiological, cardiorespiratory, and perceived responses. Some symptoms can be dyspnea, effort perceived, or discomfort, among others. These findings indicate that the use of masks is not harmful to individuals' health. It does not present any significant detrimental effect on physical performance or risk to their well-being. However, further experiments are required to corroborate the findings of this review.

Structure of the training program during the COVID-19 confinement in spanish professional football, a coach survey.

OBJECTIVES: To describe and analyze the training programs carried out during the COVID-19 forced confinement in men´s professional football in Spain. METHODS: Observational Study based on a telematic ad-hoc questionnaire developed to meet the objective of the study. The sample consisted of thirty-six coaches representing thirty-six professional men's soccer teams in the Spanish first and second division. RESULTS: Training programs developed during confinement prioritized conditioning and functional emphasis, in addition to general and nonspecific resistance training, due to contextual limitations. CONCLUSION: The structure of training during the COVID-19 confinement was limited by contextual circumstances. This study has made possible to record the training and strategies used in professional football during a confinement due to a worldwide state of alarm, with the aim of resuming competitive activity in the best possible conditions.

Effects of two exercise programmes on joint position sense, dynamic balance and countermovement jump in male amateur football players. A randomised controlled trial.

Introduction: The injury prevention and warm-up exercises programmes improve physical performance and injury ratio, but it is poorly investigated in amateur football. Objectives: To assess the effects of two warm-up multi-station programmes (IAI-Programme and FIFA11+) through JPS, LSDT and CMJ. Study design: Randomised controlled trial. Methods: 36 football players were randomised into 2 groups: IAI-Programme (n = 18) and FIFA11+ (n = 18) and performed the intervention protocol for 6 weeks. JPS, LSDT and CMJ were measured at baseline, after 6, 10 and 18 weeks (from baseline). The inter-group and intra-group differences were assessed by repeated-measures analysis of variance test (ANOVA). Results: Significant differences between groups were found after 18 weeks in the absolute angular error (-2.18[-4.33,-0.047], d = 0.69, p < 0.05) of the JPS and in the CMJ (p = 0.001, ŋ2p=,0.298) in favour of IAI-Programme when compared to FIFA11 +. No significant differences between groups were found in the LSDT. There were also intra-group differences observed in the LSDT in both groups. Conclusions: IAI-Programme can provide sensitive benefits with respect to the proprioceptive ability of knee flexion and CMJ than FIFA11 +. Both IAI-Programme and FIFA11+ present improvements in the dynamic postural control measured by the LSDT.

[Effect of contextual factors in body composition of professional soccer players. A retrospective study]. / Efecto de factores contextuales en la composición corporal de jugadores profesionales de fútbol. Un estudio retrospectivo.

INTRODUCTION: The requirements of physical demands in soccer have evolved in recent years, determining the need to investigate those aspects that condition athletic performance. The objective of this study was to describe the incidence of individualized training, company at meals, race, and demarcation on the anthropometric variables of professional soccer players since these four factors affect body composition, which is considered a predictor of performance and an indicator of lifestyle in these individuals. For this purpose, a retrospective study was developed in 51 professional players of the Spanish Football League Second Division B during the 2015/2016, 2016/2017, and 2017/2018 seasons. The anthropometric assessment was carried out under the technical standards of measurement recommended by the International Working Group of Kinanthropometry, adopted by the International Society for the Advancement of Kinanthropometry (ISAK). The results revealed that individualized training and company during meals were the factors that most influence exerted on the anthropometric variables that were collected. The values of fat mass and muscle mass, and the sum of fold measurements are sensitive to the effect of the intervention with these factors. The highest levels of interaction occurred between company during the meals and individualized training, and between demarcation and company during the meals. Considering body composition as an aspect to be taken into account in the development of performance, it should be considered that the application of certain training contents according to the individual characteristics and lifestyle of players are factors that may have a significant influence on professional soccer players.

INTRODUCCIÓN: La exigencia de las demandas físicas en el fútbol ha evolucionado en los últimos años, poniendo de manifiesto la necesidad de investigar sobre aquellos aspectos que condicionan el rendimiento deportivo. Es por esto que el objetivo de este estudio fue describir la incidencia del entrenamiento individualizado, la compañía en las comidas, la raza y la demarcación sobre las variables antropométricas en jugadores de fútbol profesional. Para ello se desarrolló un estudio retrospectivo sobre 51 jugadores profesionales de la Segunda División B española durante las temporadas de 2015/2016, 2016/2017 y 2017/2018. La valoración antropométrica se realizó bajo las normas técnicas de medición recomendadas por el International Working Group of Kinanthropometry, adoptadas por la International Society for the Advancement of Kinanthropometry (ISAK). Los resultados revelaron que el entrenamiento individualizado y la compañía en las comidas fueron los factores que más influyeron sobre las variables antropométricas. Los valores de masa grasa y de masa muscular, y el sumatorio de pliegues son sensibles al efecto de la intervención sobre dichos factores. Los mayores niveles de interacción se producen entre la compañía en las comidas y el entrenamiento individualizado, y entre la demarcación y la compañía en las comidas. Considerando la composición corporal como un aspecto a tener en cuenta en el desarrollo del rendimiento, se concluye que la aplicación de ciertos contenidos del entrenamiento según las características individuales y el estilo de vida de los jugadores es un factor que posee una influencia significativa sobre los futbolistas profesionales.

Pressure pain sensitivity over nerve trunk areas and physical performance in amateur male soccer players with and without chronic ankle instability.

OBJECTIVE: Chronic ankle instability (CAI) is reported after ankle sprain. Our aim was to assess differences in mechanical pain sensitivity of lower extremity nerve trunks and physical performance between amateur soccer players with and without CAI. DESIGN: A cross-sectional case-control study. SETTING: Amateur soccer teams. PARTICIPANTS: Fifty-five male soccer players, 28 with and 27 without CAI participated. MAIN OUTCOME MEASURES: The perceived instability was assessed with the Cumberland Ankle Instability Tool (CAIT). Pressure pain thresholds (PPTs) on the common peroneal and tibialis nerve trunks, vertical jump, lateral step-down test and joint position sense of the knee were assessed by a blinded assessor. RESULTS: Soccer players with CAI showed lower PPTs over the common peroneal nerve than those without CAI (between-groups mean difference: 1.0 ±â€¯0.8 kg/cm2, P < 0.001). No differences for PPT over the tibialis posterior (P = 0.078) or any physical performance outcome (knee joint positioning sense [P = 0.798], lateral step-down test [P = 0.580] and vertical jump variables [all, P > 0.310]) were found. PPT over the common peroneal nerve exhibited a significant moderate correlation with the CAIT score (r = 0.528, P < 0.001). CONCLUSION: Amateur soccer players with CAI have higher pressure pain sensitivity over the common peroneal nerve but exhibit similar physical performance to amateur soccer players without CAI.