Jorge Arede

This study proposed and applied a pathway-based spatial approach to elite football development by distinguishing three complementary hotspot functions: passage, permanence, and transition. Using a retrospective cohort of 154 players who made their senior debut for Athletic Club, we reconstructed player-age location histories over the developmental period from ages 10 to 22 and analysed 1889 player-age observations. A transition was defined as a change in recorded location between consecutive ages. Descriptive, inferential, survival-style, and network analyses were used to examine player movement, pathway stabilisation, and location-level hotspot structure. The cohort recorded 331 location transitions; players passed through a median of three entities and made a median of two transitions. Transitions were unequally distributed across age intervals, χ ² (11) = 47.60, p < .001, with the highest transition probabilities observed at ages 21 (33.8%) and 20 (27.9%). Location 1 dominated the network, accounting for 77.3% of players, 43.8% of player-years, and 29.3% of throughflow activity. However, after excluding Location 1, ten robust hotspots remained, led by Location 2, Location 3, Location 4, and Location 5. Half of the cohort had stabilised in their final entity by age 19, while 33.8% remained mobile at age 21. These findings show that elite football formation can be examined not only through where players are born or selected, but also through the locations where they pass, remain, and move during development.

This study aimed to investigate the potential relationship between maturity offset and cardiopulmonary responses, and to determine at which relative time points these responses differ markedly throughout the exercise duration. Ninety-two trained youth male soccer players performed progressive cycling to exhaustion on an ergometer with simultaneous breath-by-breath assessment of key cardiopulmonary parameters, including oxygen uptake (VO ₂ ), carbon dioxide production (VCO ₂ ), minute ventilation (VE), oxygen saturation (SpO ₂ ), heart rate (HR), and heart rate reserve (HRR). The quantile and functional concurrent regression analyses revealed that maturity offset significantly and variably associated with the magnitude, distribution, and time-dependent changes in cardiopulmonary responses. The findings revealed maturity-dependent cardiopulmonary response patterns; VO ₂ and VCO ₂ showed positive maturity effects across all quantiles, and inter-individual variability decreased with advancing maturation as the lower (τ = 0.10) and upper (τ = 0.90) quantiles converged toward the median at later maturity stages. Furthermore, functional concurrent regression analyses revealed that relationships with maturity offset were more pronounced in VO ₂ and VCO ₂ from the 10% iso-time onward (p < 0.001), and in VE from the 40% iso-time onward (p < 0.001). In contrast, estimated maturity offset effects on VO ₂ peak, HR and HRR were only transient, appearing in early-to-mid exercise stages (p < 0.050) but diminishing toward later time points. These findings suggest that maturity advantages in cardiopulmonary responses become more pronounced at starting or relatively moderate intensities (≥10−40% of iso-time points), whereas cardiovascular capacity showed smaller differences and tended to converge toward maximum effort. Practitioners should consider maturity offset when interpreting CPET profiles in youth athletes.

Objectives: This study compared the effectiveness of traditionally-planned (TPT) and randomly-planned (RPT) jump training regimens on physical performance metrics in youth academy soccer players. The groups undertook jump training with identical total programme volume and intensity, differing only in the order in which the prescribed training weeks were executed. Design: A total of 28 male youth academy soccer players (mean age: 12.6 ± 0.26 yrs; height: 158.1 ± 7.24 cm; mass: 43.3 ± 5.1 kg; maturity offset: 0.81 ± 0.38 yrs; soccer experience: 4–5 years) were randomly assigned to either TPT or RPT groups, undertaking an eight-week training programme. Methods: While the TPT group executed a planned training programme, the RPT group undertook identical training weeks performed in a randomised order with all other training variables being the same between the groups. Results: Results indicated significant within-group improvements across all metrics (sprint speed [10 m, 20 m, 30 m], countermovement jump [CMJ], drop jump, and change of direction speed; [dz = 0.37 to 1.15; p = <0.001]) except for the change-of-direction (CoD) test with no ball. No significant between-group differences were found except for in the CMJ, where the TPT group outperformed RPT (dz = 1.15 vs. 0.45, p < 0.001). Conclusion: These findings suggest that RPT regimens may yield similar performance outcomes to TPT programmes when matched for jump volume and intensity, though there may be a specificity advantage to using planned schemes. Using more flexible approaches might prove beneficial over time as it appears to encourage greater variability and could benefit coaches who are negatively affected by scheduling difficulties or other time constraints to a programme. This pilot investigation can help coaches and future researchers by serving as a basis for further study of flexible planning in youth populations and can provide preliminary guidance on how coaches can establish effective training programmes without necessarily having to adhere to rigid frameworks.

This randomized controlled study aimed to examine the effects of a six-week Differential Learning (DL)-based adaptation of the FIFA 11+ Kids warm-up program on selected physical performance outcomes, including agility, sprint speed, and jump performance in youth male basketball players (mean age = 13.2 ± 0.8 years). A pre-post test design was used, with twenty participants randomly assigned to either a basketball-adjusted FIFA 11+ Kids (BB-adjusted FIFA 11+ Kids) group or a DL-based warm-up group. Bayesian repeated-measures ANOVAs, along with Bayesian independent- and paired-samples t-tests, were conducted to evaluate between- and within-group changes. Between-group analyses showed inconclusive evidence for differences in sprint (BF ₁₀ = 0.41), agility without the basketball (BF ₁₀ = 0.55), agility with the basketball (BF ₁₀ = 0.54), and jump performance (BF ₁₀ = 0.40). Bayesian evidence indicated comparable pre-to-post improvements in both groups across all performance measures. These results suggest that a short-term DL-based warm-up results in comparable performance outcomes to the basketball-adjusted version FIFA 11+ Kids program. Future research should investigate whether extending DL-based approaches beyond an acute warm-up context, such as implementing them across training periods longer than six weeks and including retention testing, affects performance outcomes in youth athletes. In addition, examining different levels and types of variability (e.g., geometric versus dynamic noise) may help clarify context-dependent effects of DL-based warm-ups.

Background: This study examines how contextual factors influence the match load experienced by U14 athletes. Methods: Ninety-six male players from eight Portuguese regional selection teams were monitored during three official matches each, using WIMU Pro™ inertial devices with ultra-wideband (UWB) tracking systems. Fifteen internal and external load variables were analyzed, including player load/min, high-speed running (HSR), maximum heart rate (HRmax), and high impacts/min. Mixed linear models revealed significant inter-individual variability in all variables, showing sensitivity to match context. Results: Losing teams exhibited higher player load/min. Balanced matches provoked greater cardiovascular and locomotor demands, particularly in HRmax and HSR metrics. Cluster analysis identified three match typologies based on score margin. Team level was strongly associated with final outcomes and quarter performance, reinforcing the predictive value of intra-match consistency. In contrast, match type (score margin) showed limited correlation with team quality or load distribution. Conclusions: These findings demonstrate the multifactorial nature of match load in youth basketball, supporting the implementation of individualized, context-aware training and recovery strategies while guiding long-term athlete development.

Background and Objectives: Asymmetries in body composition and movement patterns are common in professional basketball due to the sport’s repetitive and unilateral demands. While both structural and functional asymmetries have been independently studied, little is known about their interaction under real training conditions. The aim of this study was to compare structural asymmetries, obtained from bioelectrical impedance analysis, with functional asymmetries, measured through inertial devices in professional basketball players. Methods: Twenty-five male professional basketball players from two Spanish teams were monitored over a two-month period. Structural asymmetries were assessed via the TANITA MC-780MA multi-frequency analyzer, while functional asymmetries were quantified using WIMU Pro™ inertial units during 43 training sessions. Descriptive, correlational, and cluster analyses were performed, followed by linear mixed-effects models adjusted for individual random effects, with statistical significance set at p < 0.05. Results: Descriptive results revealed low overall fat mass and no relevant group-level asymmetries in muscle mass or functional variables, although fat mass asymmetry showed greater variability across players. Correlation analyses indicated weak and non-significant relationships between structural and functional asymmetries. Cluster analysis grouped muscle mass and functional asymmetries together, while fat mass asymmetry formed a distinct cluster. Linear mixed-effects models confirmed significant differences for muscle mass asymmetry and demonstrated high inter-individual variability. Conclusions: Structural and functional asymmetries behave independently, with muscle mass asymmetry showing greater variability and functional relevance. These findings highlight the need for individualized monitoring approaches integrating morphological and functional assessments to optimize performance and reduce injury risk in elite basketball players.

Background/Objectives: Differential learning (DL) amplifies natural fluctuations in movement execution and, in its more extreme forms, facilitates repetition-free training with minimal external feedback. While increasingly recognized in the field of skill acquisition, its application in anterior cruciate ligament (ACL) rehabilitation remains underexplored. Methods: This study examined the application of DL in the rehabilitation of an 18-year-old trained basketball player following left-ACL reconstruction. The athlete completed a 42-week rehabilitation program in which DL principles were incorporated throughout the pre-operative, early, mid-, and late phases, culminating in return to sport. Training included differential mobility work, motor control, plyometric exercises, and sport-specific drills. Functional recovery was evaluated using single-leg hop tests, change-of-direction tasks, and sprint performance, while self-reported knee function was monitored via the International Knee Documentation Committee (IKDC) questionnaire. Results: Results indicated substantial improvements in both functional performance and psychological readiness. The IKDC score increased from 13.8% at baseline to 95.4% postoperatively, reaching the normal functional range. An ACL-RSI score of 85.2%, and inter-limb asymmetries were reduced to below 10%. Strength, agility, and sprint performance exceeded pre-injury levels. Conclusions: DL again shows potential as an effective approach to facilitating recovery and return to sport after ACL reconstruction, but larger controlled studies are needed for validation.

The purpose of this study was to assess the effect of modifications in field size, number of players, and goal size on the goalkeeper’s actions in competition in male youth soccer (n¼4) (under-12). A quasi-experimental design was implemented to measure the effects of the changes in the number of players per team (8-a-side vs. 5-a-side), goal size (62m vs. 32 m), and field size (5838m vs. 3820 m) on the offensive and defensive technical and tactical actions of the goalkeeper. Four male under-12 goalkeepers (age¼11.330.6 years, average weekly training¼2.450.3 h, and years of experience¼4.80.9 years) were analyzed in three tournaments (8-a-side; 5-a-side; 8-a-side). The dependent variables were: defensive and offensive technical actions taken by the goalkeepers and the way their actions were carried out. The results show that in the 5-a-side soccer matches, goalkeepers carried out more defensive actions (8-a-side: 31.23.8; 5-a-side: 77.755.0; 8-a-side: 39.56.0; F2,6¼111,218, p¼.000, 2¼.974; ES .998) and offensive actions (8-a-side: 58.07.1; 5-a-side: 84.013.5; 8-a-side: 58.19.2; F2,6¼16,257, p¼.004, 2¼.844; ES .996) than in 8-a-side soccer matches. The reduction in field size, number of players, and goal size resulted in under-12 goalkeepers having more interaction and more variability in their actions. This information could help the different stakeholders to adapt or design the youth soccer competition rules in a way that allows goalkeepers to have more experiences.