Effects of Different Recovery Duration on External and Internal Load Measures during Bouts of Small-Sided Games.

The aim of this study was to analyse the effects of different recovery times between bouts of small-sided games (SSG) on external and internal load variables in semi-professional soccer players. Sixteen male semi-professional soccer players performed three 4 vs. 4 + goalkeeper SSG training sessions, each with different recovery bout duration: short (1 min) (SSG1), medium (2 min) (SSG2), and long (4 min) (SSG4). Time motion and neuromuscular measures were collected during all SSGs, in addition, the rating of perceived exertion (RPE) was determined at the end of the last bout of each SSG. Results showed a significant increase in the total number of accelerations (p = 0.016, ES = 0.97, large) and decelerations (p = 0.022, ES = 0.81, large) in SSG4 compared to SSG1. In terms of the internal load, SSG2 showed significantly higher RPE values (p = 0.011, ES = 1.00, large) in comparison with SSG1. If the sessions' focus is on neuromuscular training, longer recovery times between SSG bouts should be used. Conversely, if the aim is to reach a higher total and running distance at different intensities, a 2-min recovery period between bouts may be more appropriate.

Do small-sided games prepare players for the worst-case scenarios of match play in elite young soccer players?

The aim of the study was to determine whether the physical performance of young soccer player during various small sided games (SSGs) underloads, replicates or overloads the requirements of the worst-case scenarios (WCS) during match play. A total of 521 SSGs' individual observations and 15 different formats of SSGs with different areas per player (ApP) (ApP100: < 100; ApP200: ranged from 101 to 200; ApP300: > 201, all in m2 · player-1) were taken into consideration. Whole (90-min average; OM) and 15-, 5- and 1-min worst-case scenarios (WCS15, WCS5 and WCS1, respectively) were analysed. Total distance covered relative (m · min-1) (TDCR), high-speed distance relative (m · min-1) (HSDR), very high-speed distance relative (m · min-1) (VHSDR) and sprint distance relative (m · min-1) (SDR), player load relative (PLR) and both total (ACCR) and high intensity relative accelerations (n · min-1) (ACCHR) were collected. All external load measures analysed were significantly higher in WCS1 compared to WCS of longer duration and SSGs with different ApP (p < 0.001). The analysis demonstrated interactions between game type and player positions (p < 0.001) for TDCR, VHSDR, PLR and ACCHR. The SSG formats did not sufficiently stimulate the WCS for locomotor demands (VHSDR and SDR). SSGs played on an ApP100 overestimated the mechanical values compared to WCS15 and WCS5. The analysed SSG formats did not sufficiently stimulate players to cope with all external load demands that occurred during WCS1. This study provides useful information for practitioners on the heightened impact of different SSG formats on external load in relation to the WCS of competitive match play.

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.

Relationships between RPE-derived internal training load parameters and GPS-based external training load variables in elite young soccer players.

This study aimed to identify the GPS-based external training load variables that influence the internal training loads (RPE-derived parameters: RPE and session RPE - sRPE), and generate a model to predict GPS-based external load variables from RPE and perceived wellness values. Training load data for 21 elite young players were collected over 72 training sessions and 23 matches from the same competitive season, and 564 observations (training sessions, 462; matches, 102) were analysed. Considering all observations (training sessions and matches), significant moderate and large correlations (p < 0.01) were detected between RPE values and EL measures. The correlation between the GPS outcomes with both the RPE and sRPE values was higher during training sessions than during matches. Moreover, increased RPE and perceived wellness measures had a significant positive effect on external load variables (p < 0.001). The present work provides preliminary evidence of the utility of the RPE and sRPE method to quantify the training loads in young soccer players since most of the GPS-based EL indicators were moderate to highly correlated with the RPE-derived parameters. Additionally, EL variables may be estimated when combining perceived IL and subjective wellness indicators in young soccer players.

Field-based tests for assessing fitness in referees: A systematic review.

This systematic review was aimed at identifying the psychometric properties of field-based tests for assessing physical fitness in soccer referees. Electronic databases were searched up to May 2020 for studies that informed about the reliability and/or validity of at least one field-based physical fitness test for soccer referees. A total of 13 studies analysed the psychometric properties of the field-based physical fitness tests proposed by the Fédération Internationale de Football Association (FIFA) (aerobic endurance, n = 8; anaerobic endurance, n = 3; and speed, n = 8), while seven investigations focused on field-based physical fitness tests specifically designed for assessing aerobic endurance (n = 1) or change of direction (COD) (n = 6). According to the observed reliability and validity values, the Assistant Referee Intermittent Endurance test (ARIET), the 50-m sprint test and the Modified Agility test (MAT) seem, respectively, the best available options for assessing aerobic endurance, speed, and COD in soccer referees. Future investigations should consider the lack of research focusing on assistant and female referees. Further studies on the psychometric properties of anaerobic endurance and short distance speed tests are also needed.

Small-sided games in female soccer players: a systematic review.

INTRODUCTION: This systematic review aimed to analyze the literature on small-sided games (SSGs) from a physiological and physical perspective in female soccer players. EVIDENCE ACQUISITION: A systematic review of Web of Science, PubMed, Scopus and SPORTDiscus was performed according to PRISMA (Preferred, Reporting Items for Systematic reviews and Meta-Analysis) Guidelines. Studies informed about physical and/or, physiological-responses during SSGs played by young and/or adult amateur and/or professional female soccer players were included. Information regarding study information, population, intervention data, instruments, variables analyzed, and outcomes were elucidated. EVIDENCE SYNTHESIS: The search returned 2944 records. After screening against set criteria, a total of 13 manuscripts were fully reviewed. The present review grouped studies according to the three following age categories taking sample's mean age into account: Under-19 as young players and senior female players (>19 years old). The most common topics of analysis were: 1) player number; 2) pitch area and game surface; 3) sex differences; and 4) training regimens. CONCLUSIONS: This review provides useful information on the complex relationship between technical, physical and physiological interactions in SSGs and how manipulating these types of variables can improve the soccer training process.

Accumulative Weekly External and Internal Load Relative to Match Load in Elite Male Youth Soccer Players.

PURPOSE: The aim of this study was 2-fold: (1) to assess and compare the external and internal load of elite young soccer players during competitive microcycles and (2) to describe the training/match ratios (TMr) in elite male youth soccer players. METHOD: Twenty-one youth soccer players were monitored using a 10-Hz global positioning system. Total distance covered, running distance (RD), high-speed RD, sprint distance, number of accelerations and decelerations, player load, and rated perceived exertion were recorded during training sessions and matches. The TMr was calculated for each load measure. All variables were also normalized dividing the load per minute of activity. RESULTS: The RD, high-speed running, and sprint distance were higher 3 days before the match and 2 days before match compared with the rest of the training sessions. However, accelerations, decelerations, and player load were higher 4 days before match than other sessions. Besides this, the TMr of RD, high-speed running, and sprint distance were associated with lower values than the TMr of total distance covered, accelerations, decelerations, and player load. The match constituted the highest load during competitive microcycle. CONCLUSIONS: The present data support the idea that youth soccer coaches and practitioners must consider relative training load according to match demands to better manage and evaluate player periodization.

Effectiveness of Prison-Based Exercise Training Programs: A Systematic Review.

BACKGROUND: The promotion of physical activity among imprisoned people is a public health strategy that could help to improve the health status of this collective. This systematic review is aimed at reviewing the scientific evidence regarding the effects of exercise training programs performed by inmates. METHODS: A systematic search for randomized controlled trials aimed at identifying the characteristics and effects of prison-based exercise training programs on imprisoned people was carried through MEDLINE, SPORTDiscus, and Scopus. RESULTS: A total of 11 randomized controlled studies were selected, and the methodological quality of these was acceptable according to the Downs and Black scale. The proposed interventions were mainly based on the performance of aerobic or combined exercise training programs. Generally, the participants were healthy men who were imprisoned for at least 2 months and up to 15 years. Ten out of the 11 studies reported significant changes on physical and mental health-related variables, after the intervention took place. CONCLUSION: These findings suggest that prison-based exercise programs constitute a feasible and useful strategy for improving the physical and mental health status of prisoners.