The main objective of this research was to determine the existence of relative age effect (RAE) in five European soccer leagues and their second-tier competitions. Even though RAE is a well-known phenomenon in professional sports environments it seems that the effect does not decline over the years. Moreover, additional information is required, especially when taking into account second-tier leagues. Birthdates from 1,332 first-tier domestic players from France, England, Spain, Germany and Italy and birthdates from 1,992 second-tier domestic players for the 2014/2015 season were taken for statistical analysis. In addition to standard statistical tests, the data were analyzed using econometric techniques for count data using Poisson and negative binomial regressions. The results obtained confirmed a biased distribution of birthdates in favor of players born earlier in the calendar year. For all of the five first-tier soccer leagues there was an unequal distribution of birthdates (France χ2 = 40.976, P<0.001; England χ2 = 21.892, P = 0.025; Spain χ2 = 24.690, P = 0.010; Germany χ2 = 22.889, P = 0.018; Italy χ2 = 28.583, P = 0.003). The results for second-tier leagues were similar (France χ2 = 46.741, P<0.001; England χ2 = 27.301, P = 0.004; Spain χ2 = 49.745, P<0.001; Germany χ2 = 30.633, P = 0.001; Italy χ2 = 36.973, P<0.001). Econometric techniques achieved similar results: estimated effect of month of birth, i.e., long-term RAE on players’ representativeness, is negative (statistically significant at the 1% level). On average, one month closer to the end of the year reduces the logs of expected counts of players by 6.9%. Assuming this effect as linear, being born in the month immediately before the cut-off date (i.e., December/August), reduces the logs of expected counts of players by approximately 75.9%. Further, ID (index of discrimination, that is, the ratio between the expected counts of players born in the middle of the first and the twelfth month of the selection year) is 2.13 and 2.22 for the first- and second-tier, respectively. In other words, in the top five European first-tier and second-tier leagues, one should expect the number of players born in the first month of the calendar year to be twice the number of those born in the last month. The RAE in the second-tiers is the same as in the first-tiers, so it appears that there is no second chance for later born players. This reduces the chances to recover talented players discarded in youth simply because of lower maturity.

High levels of physical fitness (PF) can positively affect both health and cognitive function, thus monitoring its levels in youth can help increase health and quality of life in adult populations later on. This systematic review aims to identify PF field-based tests used in young European populations practicing sport to find tools that are adequate for the considered target involving a new battery within the Enriched Sport Activities (ESA) project. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was followed. In the 83 identified articles, the main tests used were: vertical/horizontal jumps (for muscular strength/power); push-ups, running at maximum effort, sit-ups (for muscular strength/endurance); multistage non-intermittent and intermittent tests (for aerobic endurance); sit and reach (for flexibility); sprinting and agility T-tests (for speed and agility, respectively); 10 × 5 m shuttle run (SR) (for both speed and agility). Few studies assessed coordination, reaction time, power, and balance. Although the selected tests are widely used and validated, they do not determine all PF aspects and do not reflect sport-specific features. A final decision was made for the inclusion of the following tests: standing broad jump, seated medicine ball throw, 20 m SR test, 30 m sprint, Illinois test, and a new test, i.e., the crunning test, to assess different skill-related components at once. The use of this combination of tests allows for the assessment of all PF components and can help planning effective training programs and cultivate sporting talent.

Recreational football has been shown to be an effective health-promoting activity, but it is still unclear how changes in game formats affect external and internal load. The aim of this study was therefore to evaluate the effect of area per player in recreational small-sided football games. Ten recreational active male football participants (mean±standard deviation, age: 20.1±1.1 years; height: 182.2±7.4 cm; body mass: 75.9±9.8 kg) completed two sessions comprising 2x20 min of 5v5 football with 80 and 60 m 2 per player, during which heart rate (HR) and movement pattern were measured. In 80 m 2 , mean HR (167±9 vs. 160±10 b.p.m., P<0.001, ES=0.70) and peak HR (192±8 vs. 188±9 b.p.m., P=0.041, ES=0.50) were significantly higher than in 60 m 2 . Percentage playing time with HR >90%HR peak was higher in 80 m 2 than 60 m 2 (45±14 vs. 29±16%, P=0.004, ES=1.07). Moreover, a higher number of sprints (8.0±4.8 vs. 3.0±1.3, P=0.014, ES=1.41) and a greater distance in the highest speed zones (>13, >16 and >20 km·h 1 ) were covered in 80 m 2 than 60 m 2 . Peak running speed was also higher in 80 m 2 (24.3±1.7 vs. 22.3±1.4 km·h -1 , P=0.011, ES=1.27), whereas no statistically significant differences were found in total distance covered, player load, or the acceleration-deceleration profiles. In conclusion, the internal and external loading was higher for recreationally active male football players when playing on a pitch with 80 m 2 area per player compared to 60 m 2 .

Background: Physical fitness in youth is a predictor of health in adulthood. The main objective of the present study was to understand if an enriched sport activity program could increase physical fitness in a population of schoolchildren. Methods: In a sample of 672 children aged 10.0 ± 1.90 years, different motor skills were tested by the 1 kg and 3 kg ball throw (BT), the standing broad jump (SBJ), the 30 m sprint (30mS), the leger shuttle run (LSR), the illinois agility test (IGT), and the quadruped test (QT). Within the controlled-trial, the intervention group (ESA) underwent an additional warm-up protocol, which included cognitive enhancing elements, for 14 weeks while the control group continued with ordinary exercise activity. Results: A significant increase was present regarding the 1 kg and 3 kg BT, the SBJ, the 30mS, and the IGT, while no significant difference was shown regarding the QT and the LSR in the ESA group between pre and post intervention. In the control group, no differences were present for any test except for the QT and the LSR post-test. Conclusion: A 14-week structured physical intervention had moderate effects regarding throwing, jumping, sprinting, and agility in a sample of schoolchildren.

Success in different soccer skills like kicking depends on motor abilities achieved. Kicking is a soccer fundamental, which depends on many different and complex factors (technique, foot-ball interaction, ball flight, etc.). Therefore, it is important to identify players that are able to perform faster kicks using both dominant and non-dominant leg. The current study investigated some basic variables of different soccer kicking speed and their relevance to success in youth soccer academy. 119 players from the first and the second division participated to this study. They were randomly divided into age groups (U-15, U-17, and U19) and team status (first team, reserves). The diagnostic ability of the different ball kicking speed tests in capturing differences between first team players and reserves among different age categories were computed using the receiver operating characteristics analysis. Results demonstrated that first team players achieved better results when comparing to reserves in each category. In addition, differences were greater in the U-15 and the U-17 than in the U-19 age group. In conclusion, ball kicking speed could be one of the possible identification tools to evaluate players' success in youth soccer.