Children with mild intellectual disability (MID) have significant limitations in both intellectual functioning and cognitive, social, and motor skill behaviors. Understanding the development of physical fitness in boys and girls with MID, and identifying sex-related differences can help devise interventional programs to improve physical fitness in these groups. The aim of this study was to compare sex differences in the time-dependent changes in health-related physical fitness components in individuals with MID. A longitudinal design was employed over three years. A total of 111 individuals with MID (46 girls and 65 boys) aged between 10 and 14 years (mean age 11.97 ± 1.39 years) participated in the study. The physical fitness levels of the participants were assessed using the Brockport Physical Fitness Test (BPFT) battery. The tests included body composition (body height, body mass, and body mass index), aerobic endurance (15 m Progressive Aerobic Cardiovascular Endurance Run (PACER) test), and musculoskeletal function (dominant handgrip strength, back-saver sit-and-reach, and trunk lift). The results revealed that, over time, the longitudinal developmental trajectories for body mass, body height, aerobic endurance, and dominant handgrip strength were more favorable for boys. However, the longitudinal development curves for body mass index (BMI), trunk lift, and flexibility were similar for both boys and girls. The findings of this study provide valuable evidence for developing targeted physical activity programs for individuals with MID, and demonstrate the need for programs aimed at increasing aerobic endurance and muscle strength in girls with MID.

The study aimed to analyse the psychometric properties of the Coach Behaviour Scale (CBS-SA) in Saudi Arabian athletes. The sample consisted of 201 athletes (Mage = 19.39, SD = 2.13; 135 men and 66 women) who completed the Coach Behaviour Scale in Arabic and an Arabic version of the Coach-Athlete Relationship Questionnaire. Results from the confirmatory factor analysis and exploratory structural equation modelling supported the presence of six factors in the CBS-SA rather than the seven in the original version. However, exploratory structural equation modelling revealed that fifteen items did not reach adequate factor loadings. Consequently, a 33-item, 6-factor version of the questionnaire was identified as a suitable solution based on both confirmatory factor analysis and exploratory structural equation modelling. In conclusion, the CBS-SA demonstrated adequate psychometric properties and can be used as a reliable tool to assess the most common coaching practices in Saudi Arabian athletes.

BackgroundThis study developed a comprehensive fitness test, the New Era FitScore (NEFS), integrating full-body movement with reactive agility and neuromotor components.MethodsNinety-six participants completed the NEFS: a 90-s circuit combining burpees with reactive sprints triggered by randomized Witty SEM lights. Reliability was assessed using Intraclass Correlation Coefficient (ICC) and Bland-Altman (bias, 95% limits), and predictors of NEFS performance were examined using linear regression.ResultsBody composition showed significant negative correlations with NEFS across all groups. In female students, fat percentage demonstrated the strongest association (r = −0.631, p = 0.002), followed by BMI (r = −0.535, p = 0.010). Male students showed significant correlations with body mass (r = −0.578, p = 0.015) and BMI (r = −0.578, p = 0.015). In sedentary women, fat percentage again showed the highest correlation (r = −0.638, p < 0.001), and regression analysis revealed that fat percentage explained 39%–40% of NEFS variance across female groups. Among U15 soccer players, NEFS correlated strongly with Yo-Yo test distance and estimated VO₂max (r = 0.742, p = 0.002), while body composition showed weaker associations. Overall test-retest reliability was high [ICC (2,1) = 0.940, 95% CI:.906–0.961] and was broadly consistent across groups, with ICC values ranging from.812 to.973.ConclusionBased on the study sample and analysis, the NEFS is a valid and reliable multidimensional assessment evaluating muscular strength-endurance, aerobic capacity, agility, and coordination in a single 90 s protocol. With favorable neuromuscular properties and minimal equipment needs, it is a practical tool for fitness evaluation in sports, health, and other communities.

Abstract Despite the growing availability of performance data in professional soccer, existing player rating systems lack positional specificity and fail to capture the multidimensional demands of center forwards. Building on composite index and regularized regression approaches in sports analytics, this study develops a Soccer Performance Index (SPI) tailored to center forwards in the English Premier League (EPL) across the 2021–2024 seasons. Data from 194 player-season observations were analysed using 109 Wyscout performance metrics as predictors. Three SPI versions were constructed using Lasso and Ridge regression: one based on market value, one on the InStat Index, and a hybrid combining both. The hybrid model, weighting market value at 70% and the InStat Index at 30%, achieved the strongest explanatory fit (R 2 = 0.676, RMSE = 0.669), accounting for approximately 68% of variance in player valuation — a result consistent with the complexity inherent in behavioural and performance modelling contexts. xG per 90, shots, and key passes per 90 emerged as the strongest predictors. Methodological considerations include the use of a minimum participation threshold (≥ 20 matches), which may introduce survivorship bias; the treatment of player-season observations as independent units, which does not account for repeated-measures dependence; and the reliance on internal validation only. The SPI demonstrates ecological relevance by integrating both financial and on-field performance indicators, offering a structured framework for talent identification and recruitment support in applied professional contexts.

BackgroundStrength training (ST) for runners is typically based on low volumes and high intensities. However, alternative approaches emphasizing higher volume and lower intensity, such as protocols with high time under tension (TUT), remain underexplored in this population. Notably, the effects of high-TUT may vary depending on the predominant type of muscle contraction.ObjectivesTo analyze the impact of strength training with high time under tension on different muscle actions in performance-related variables in runners.MethodsThirty-four physically active young males were randomly divided into three groups: dynamic strength training, isometric strength training, and a control group. Over four weeks, the training groups performed two weekly sessions of bodyweight exercises with equalized time under tension per set (84 s), adjusted according to the type of contraction. The primary outcomes were performance in a 3000-meter time trial, peak torque, countermovement jump, neuromuscular fatigue, internal running load, ground contact time, and vertical oscillation. The data were analyzed using a two-way repeated measures analysis of variance.ResultsPeak torque increased by 13.3% in the dynamic group and 14.2% in the isometric group, compared with 2.5% in the control, with statistical significance only for the isometric group (p = 0.034, d = 1.12). Vertical jump height improved by 5.4% in the dynamic group and 4.1% in the isometric group compared with 0.7% in the control (p = 0.003, d = 1.54 and p = 0.030, d = 1.13, respectively).ConclusionIn conclusion, high time under tension strength training, both dynamic and isometric, improved neuromuscular characteristics in runners. However, these adaptations did not translate into significant changes in running performance or running economy over the duration of the intervention.Trial registrationThis trial was registered in the Brazilian Clinical Trials Registry (ReBEC) with the identifier RBR-686kqdx.

(1) Background: As university students increasingly engage with digital tools in their academic and daily lives, digital well-being has become an important issue. This study aimed to examine a comprehensive sequential mediation model in which cognitive flexibility and digital literacy explain the relationship between metacognitive awareness and digital well-being among university students. (2) Methods: This cross-sectional correlational study included 711 university students. Data were collected using the Metacognitive Awareness Scale, Cognitive Flexibility Inventory, Digital Literacy Scale, and Digital Well-Being Scale. The proposed model was tested using structural equation modeling, and indirect associations were examined using bootstrap analyses. (3) Results: The findings indicated that metacognitive awareness was positively associated with cognitive flexibility and digital literacy, whereas cognitive flexibility was positively associated with both digital literacy and digital well-being. Digital literacy was also positively associated with digital well-being. Bootstrap results supported significant indirect associations between metacognitive awareness and digital well-being through cognitive flexibility and digital literacy, including their sequential mediation. (4) Conclusions: These findings suggest that university students’ digital well-being can be better understood by considering metacognitive awareness, cognitive flexibility, and digital literacy together. Therefore, holistic approaches that focus on developing these three areas together may be beneficial in interventions aimed at supporting digital well-being.

Purpose This study aimed to investigate the prevalence of W-sitting, gait, and foot analysis in preschool and school-age participants. Methods A cohort study was conducted, including healthy participants without any pathology or other diagnoses. Foot disposition was determined using the Foot Posture Index (FPI-6), and gait patterns were analysed using the Zebris FDM platform. The study was conducted at the Gait Laboratory of King Abdullah Specialised Children’s Hospital and Prince Sultan University in Riyadh, Saudi Arabia. A total of 190 participants were included, ranging in age from 12 to 109 months. The preschool-aged children (12–60 months) comprised 168 participants (88%), while the school-aged children (61–109 months) comprised 22 participants (12%). Results The preschool group had a female majority (92, 55%), while males accounted for 76 participants (45%). W-sitting was observed in both groups, with 61 preschool participants (36%) and eight school-aged participants (36%) preferring this posture. Gait analysis revealed patterns specific to preschool children aged 12–60 months, indicating an increased pronation on the left foot. However, the overall risk of developing foot pronation or supination deformities in Saudi participants was low, though not negligible. Conclusions W-sitting may impact foot posture and gait patterns. Early assessment of foot posture and gait during the paediatric age is recommended to minimise the risk of complications or deformities that may affect a child’s development.

Background: Nomophobia is increasingly common and may impair daily functioning, academic performance, and social relationships. Although neuroticism has been linked to nomophobia, the role of digital stress in this association remains unclear. This study examined the indirect association between neuroticism and nomophobia through digital stress and whether emotion management skills moderated the digital stress–nomophobia association. Methods: Data were obtained from 434 undergraduate students using self-report measures. Hypotheses were tested with PROCESS Macro Model 14 in SPSS, controlling for gender and using bootstrap confidence intervals. Results: Neuroticism was associated with higher digital stress, and higher digital stress was associated with greater nomophobia. A significant statistical indirect effect of neuroticism on nomophobia through digital stress was observed, whereas the direct association between neuroticism and nomophobia was not statistically significant after digital stress was included in the model. Emotion management skills showed a small but statistically significant moderating effect on the digital stress–nomophobia association; however, the observed pattern was not protective. The association between digital stress and nomophobia was slightly stronger among students with higher emotion management skills. Conclusions: The findings support a statistical indirect association between neuroticism and nomophobia involving digital stress. Because the data were cross-sectional, the results do not establish temporal ordering or a causal mediation mechanism.

Offensive transitions in modern football have been identified as a decisive moment in a game, as they offer a high potential for scoring goals and creating defensive imbalances. To investigate the impact of offensive transitions on the performance of different national football leagues, this study analyzed data from 1151 games belonging to nine leagues/countries, which were divided into three categories: Top, Marginal, and Emerging. The classification of leagues (Top, Marginal, Emerging) is used as a proxy for competitive context rather than a direct measure of tactical quality. A total of 3497 goals were scored in these games, and they were classified according to their origin, including: (i) non-offensive transitions (NT), (ii) direct offensive transitions (OT), (iii) set pieces (SP), and (iv) positive outcomes of offensive transitions (POS OUT). Results showed that Top Leagues scored significantly more goals from offensive transitions (mean difference of 0.28 goals per game compared to Marginal Leagues, 95% CI [0.14; 0.41], and compared to Emerging Leagues, 95% CI [0.12; 0.44], respectively) and exhibited a higher goal-scoring rate from combined offensive transitions (OT + POS OUT = 53%) compared to the Emerging (42%) and Marginal Leagues (43%). Furthermore, Emerging and Marginal Leagues performed better in terms of goals scored from non-offensive transitions and set pieces, suggesting the presence of specific characteristics in these leagues. In conclusion, this study demonstrates the differential role of offensive transitions across national football leagues and the systematic variation in their contribution to goal-scoring across competitive contexts. These findings indicate that offensive transition effectiveness varies systematically across competitive contexts, and that motion analysis technology and optical sensors represent methodological avenues for further investigation of the underlying tactical and organizational determinants.

Purpose This study aims to determine the extent to which physical and motor performance can predict functional movement capacity, an important indicator of mobility and injury risk in young volleyball players. Methods A total of 41 young female volleyball players (age = 12.90 ± 1.07; height = 157.00 ± 0.06 cm; body weight = 50.54 ± 14.06 kg) who regularly participated in volleyball training and competitions voluntarily took part in the study. Physical performance components were assessed using balance, agility, and vertical jump tests, while motor performance was evaluated through the Körperkoordinationstest für Kinder (KTK3+) motor competence test. A multiple linear regression analysis was conducted to determine the relationship between these variables and Functional Movement Screen (FMS) scores. Results The analysis revealed that agility, countermovement jump (CMJ), and KTKMS were significant predictors of FMS (R = 0.780, p < 0.05), collectively explaining 60% of the variance in FMS. Specifically, agility (β = –0.369, p < 0.05), CMJ (β = 2.825, p < 0.05), and KTKMS (β = 2.242, p < 0.05) had significant and positive relationships with FMS. In contrast, static balance, dynamic balance, KTKBB, KTKJS, and KTKEHC were not significant predictors of FMS ( p > 0.05). Conclusions The combined effect of agility, vertical jump, and KTKMS movement patterns, which are closely related to volleyball-specific movements, plays a crucial role in predicting functional movement capacity and injury risk in young volleyball players. These findings are expected to contribute to the development of educational programs for athletic performance specialists and coaches.

OBJECTIVE:This study aimed to explore the motivational factors influencing physical activity among college students majoring in Science, Technology, Engineering, and Mathematics (STEM) in Saudi Arabia. METHODS:An observational, cross-cultural, and cross-sectional study was conducted at two universities in Saudi Arabia, Prince Sultan University (PSU) and King Fahd University of Petroleum and Minerals (KFUPM). Data were collected on family and PE teacher influence, availability of sports facilities and resources, persistence in physical activity, social interaction, and physical activity frequency across life stages. RESULTS:Significant differences were observed between PSU and KFUPM students in family and teacher influence, access to facilities, and engagement in physical activity. PSU students reported higher levels of family support, teacher influence, and access to facilities and resources, which correlated with greater engagement in physical activities. Conversely, despite having fewer resources, KFUPM students demonstrated higher social interaction in physical activities. Regression analysis revealed that for KFUPM, social interaction within physical education was a key predictor of physical activity frequency, while for PSU, persistence and engagement were primary, with family influence as a secondary factor. CONCLUSION:The findings underscore the role of institutional support, resource availability, and social factors in promoting physical activity among STEM students. PSU's supportive environment and access to sports facilities significantly contribute to higher physical activity engagement. In contrast, KFUPM's emphasis on social interactions highlights the role of peer networks in fostering engagement. These insights emphasize the importance of universities establishing comprehensive support systems designed to enhance student engagement in physical activities. TRIAL REGISTRATION:The study was approved by the Institutional Review Board of Prince Sultan University (Approval Number PSU IRB2022010101).

Autophagy is a key regulator of cellular homeostasis and neuronal survival, particularly under adverse physiological conditions. Environmental enrichment (EE), a non-pharmacological intervention providing enhanced sensory, cognitive, and motor stimulation, may modulate autophagic processes in the brain. This systematic review aimed to synthesize preclinical findings on the effects of EE on autophagy markers in rodent models subjected to diverse adverse conditions. A literature search across PubMed, Scopus, ScienceDirect, and embase yielded eight eligible studies meeting inclusion criteria. EE was found to be generally associated with upregulation of key autophagic markers such as Beclin-1, LC3-II/LC3-I ratio, cathepsins, p62, p-TFEB, and LAMP-1 across brain regions including the cortex, hippocampus, and penumbral area. However, reductions in some markers were also observed, indicating that the modulatory effects of EE are context-dependent and may vary with disease model, brain region, or EE protocol duration. These findings suggest that EE holds promise as an adjunctive strategy to modulate autophagy and mitigate neurodegeneration, though heterogeneity in study design and outcomes warrants caution during interpretation. Further mechanistic and sex-specific studies are needed to clarify the therapeutic relevance of EE-induced autophagic modulation.

This meta-analysis examines the effect of Cooperative Learning (CL) interventions, compared to traditional instructional methods, on students’ learning outcomes across affective, cognitive, physical, and social domains in physical education (PE). The review involved a comprehensive search of 12 databases in English, Spanish, and Turkish, with the last search conducted on June 2nd, 2024. Studies included were true experimental or quasi-experimental designs featuring direct CL interventions in PE, covering students of both genders from primary school to university levels. The standardized Cochrane methods were used to identify eligible records, collect and combine data, and assess the risk of bias. Comprehensive Meta-Analysis (CMA) v4 software package was used to yield a summary of quantitative results. Hedges’s g was used as the effect size (ES) measure, calculated from pre- and post-tests in both experimental and control groups. Forty-three studies (comprising 60 reports) were initially included, but three studies were excluded as outliers, leaving 40 studies (56 reports) with a total of 3.985 participants for analysis. The random effects model revealed a moderate positive overall effect of CL interventions (ES = 0.459, 95% CI = [0.324, 0.592], p < 0.001), indicating that CL enhances PE students’ learning across four domains. Subgroup analyses showed small to moderate ESs for affective (ES = 0.304), physical (ES = 0.471), cognitive (ES = 0.589), and social learning (ES = 0.612). Risk of bias was evaluated using Begg and Mazumdar’s rank correlation, the classic fail-safe number, and a funnel plot, all indicating a low risk of bias. Methodological quality was assessed using the Medical Education Research Study Quality Instrument (MERSQI). The study was registered on PROSPERO (ID: CRD42024532607). This meta-analysis underscores the effectiveness of CL as a student-centered pedagogical model in PE, demonstrating its positive effect on various learning outcomes in the affective, cognitive, physical, and social domains. The findings provide instructive data and strategies for researchers, practitioners, and policymakers aiming to integrate, implement, or make context-specific adaptations of CL into educational processes, while ESs in the affective, physical, cognitive, and social learning domains provide domain-based implementation guidance for these stakeholders.

This study aimed to: (1) compare the efficiency of positional attacks and counterattacks in La Liga, the Premier League, and Serie A, considering team rankings (top, intermediate, and bottom tiers); and (2) identify key factors that influenced the success of both types of attack. A quantitative, observational study adhering to STROBE guidelines was conducted. Data from five seasons (2017-2022) were collected from INSTAT, covering 5,700 matches across the three selected leagues. The analysis included 84 teams. Of the 115 team variables available, 35 independent and two dependent variables-efficiency in positional attacks and counterattacks-were selected. These variables included team performance metrics and tactical indicators. Counterattacks were more efficient than positional attacks across the three leagues, and top teams performed better than intermediate and bottom teams. Serie A showed the highest efficiency. In La Liga and the Premier League, positional attack efficiency was linked to right flank attacks, while counterattacks relied on central-zone efficiency. Serie A showed similar patterns, with the right flank contributing most to positional attack efficiency and central-zone efficiency being the strongest predictor of counterattack efficiency. The superiority of counterattacks over positional attacks underscores the importance of tactical precision and situational execution. Top teams excelled in both strategies, emphasizing the need for efficiency. The findings highlight the significance of adapting strategies to each league's unique trends. Coaches can leverage these insights to refine their approach, focusing on fast transitions, possession play, and wing play to enhance attacking efficiency and overall team performance.

Background Football demands both aerobic and anaerobic capacities due to its dynamic movements, which include jumps, directional changes, ball control, and sprints. The Nordic hamstring exercise (NHE) enhances eccentric strength, which is crucial for high-intensity movements. However, the relationship between Nordic breaking point angle (NHEbpa), which is associated with eccentric hamstring peak torque during Nordic hamstring exercise, and sprint, countermovement jump (CMJ), and change of direction (COD) speed in soccer players has not been sufficiently investigated. Objective This analysis examines the relationship between the Nordic breaking point angle and critical performance indicators—sprint speed, COD ability, and vertical jump—in football players. Methods Fifty-eight male soccer players volunteered for the study. Assessments included anthropometric measurements, CMJ tests, 10-20-30 m sprint tests, and COD (zig-zag) tests. NHEbpa was measured using motion analysis software. Correlation analysis was used to determine the relationship between variables. A multiple linear regression analysis was conducted to evaluate the individual effects of the sprint, CMJ, and COD performances on NHEbpa, with data analyzed using JASP 0.18. Results Correlation analysis showed strong positive correlations between NHEbpa and sprint performances (r = 0.633 to 0.666), moderate negative correlation between NHEbpa and CMJ (r = −0.406), and moderate positive correlation between NHEbpa and COD (r = 0.580). Regression analysis results were used to analyze the independent coefficients of multiple variables more comprehensively, revealing significant predictors for performance: 20-m sprint (β = 24.166, p = 0.030), 10-m sprint (β = 22.564, p = 0.047), 30-m sprint (β = 10.677, p = 0.027), and CMJ (β = 4.974, p = 0.034). Conversely, COD performance (β = −0.154, p = 0.470) did not demonstrate a significant effect. Conclusions The study identified significant relationships between NHEbpa and sprint/CMJ performances (p < 0.05), while no meaningful effect was observed for COD speed (p > 0.05). These findings highlight the importance of eccentric strength in sprint performance, suggesting that other factors may play a more prominent role in COD. Incorporating eccentric-focused training, particularly through Nordic exercises, is recommended to enhance sprint performance and hamstring strength, which are essential for football players.

Objective:Despite growing public health efforts worldwide, many young adults-particularly women-remain insufficiently active, often due to a complex interplay of personal, social, and environmental barriers. In the context of rapid sociocultural change in Saudi Arabia, this descriptive study aims to identify and compare perceived barriers to physical activity (PA) among male and female college students in Riyadh across key domains. Methods:This cross-sectional observational study included 437 college students (219 females and 218 males), aged 18-25 and residing in Riyadh. Data were collected in person using a validated, self-administered questionnaire comprising 39 items across nine domains assessing barriers and behavioral aspects related to PA. Results:Significant gender differences emerged in barriers such as harassment, lack of friend support, body image concerns, safety, weather, and the absence of same-gender role models. No differences were observed in PA frequency. Key factors negatively affecting PA frequency included competing priorities, weather, transportation, and fatigue. Engagement in more structured or competitive activities was hindered by environmental pollution, time management challenges, limited group support, lack of skills, and absence of role models. However, effect sizes were generally small, and the predictive power of the models was modest. Conclusion:Gender disparities in perceived barriers were most pronounced in personal, sociocultural, environmental, and health-related domains, influencing the type of PA more than its frequency. Although some gender differences were statistically significant, their effect sizes are small and should be interpreted with caution. Promoting equitable participation requires safe, female-friendly environments, stronger peer and role model support, and improved access to equipment and green spaces. Addressing body image, personal safety, confidence, skills, and time management is also essential. Given the modest predictive power of the models, other factors likely influence PA behaviors and warrant further investigation.

Background Among the key factors for cross-country skier training are high altitude training and strength in double-polling, because has recently been used not only for long-distance races but also for World cup. This study aimed to identify the effects of artificially induced high altitude on acute performance changes during aerobic (AE) and anaerobic (ANE) threshold exercises. Sport-specific tests simulating double-poling cross-country skiing were performed. Methods Eleven (8 ♂ and 3 ♀) highly trained cross-country skiers (age 19±2.81, BMI 21.9±2.1) performed a stress test to determine individual AE and ANE levels and AE and ANE intensity tests at low (500 m ASL) and artificially induced high (2000 m ASL) altitudes. The altitude was simulated using the hypoxic generator HYP-100™. For double-poling, the ergometer SkiErg® was used in the standing position. Heart rate (HR) and lactate concentration (LC) in the capillary blood were monitored. Results For the AE and ANE loads, the average HR values at an artificially induced high altitude were 3–5% higher than those at a low altitude. The differences were significant, both statistically (p<0.05) and substantively. The average LC values were neither statistically significant (p>0.05) nor substantively significant. Conclusions Not-adapted youth elite cross-country skiers have higher HR at artificially induced high altitudes (2000 m ASL) during the test on SkiErg® compare to the same load in lowland (500 m ASL). The absence of alterations in the average LC confirms that it is more appropriate to monitor the HR for altitude acute effect assessment and employ LC only for verification. For the management of endurance sports training at high altitude our research confirmed that exercise must respect the principles of acclimatization processes.

ObjectiveThe study aimed to increase our understanding of offensive transitions in football, focusing on the time spent executing them and how it is influenced by the period in which they occur and the instant score. The objective is to understand its temporal variables and how they influence the unfolding of the scoreline during a match.MethodologyThis study analyzes 1,649 goals resulting from offensive transitions in 1,151 games across three leagues categories: Top, Marginal, and Emerging leagues. Multinomial logistic regression was performed to understand associations and predictors between the variables: “duration of a transition”, “Time of offensive transition occur” and the “score at the moment”.ResultsThe research reveals that, across all league categories, the last 15 min of the first and second halves, have the highest frequency of successful offensive transitions, particularly on the last 15 min of matches. In Top leagues, 69% of offensive transitions last for 9 s or more, with slower transitions more prevalent towards the end of games. In Marginal leagues, 41% of successful transitions took 13 s or longer, while in Emerging leagues, 53% of successful offensive transitions occurred when the game was not in a 0–0 state. The results show associations between all variables in Top Leagues. No associations were found in Marginal leagues. Associations between duration of the transition and the time of the game they occur were found on Emerging Leagues.ConclusionThese findings underscore the importance of tailored strategic plans for offensive transitions, to optimize scoring opportunities and performances.

Background:Among the key factors for cross-country skier training are high altitude training and strength in double-polling, because has recently been used not only for long-distance races but also for World cup. This study aimed to identify the effects of artificially induced high altitude on acute performance changes during aerobic (AE) and anaerobic (ANE) threshold exercises. Sport-specific tests simulating double-poling cross-country skiing were performed. Methods:Eleven (8 ♂ and 3 ♀) highly trained cross-country skiers (age 19±2.81, BMI 21.9±2.1) performed a stress test to determine individual AE and ANE levels and AE and ANE intensity tests at low (500 m ASL) and artificially induced high (2000 m ASL) altitudes. The altitude was simulated using the hypoxic generator HYP-100™. For double-poling, the ergometer SkiErg ® was used in the standing position. Heart rate (HR) and lactate concentration (LC) in the capillary blood were monitored. Results:For the AE and ANE loads, the average HR values at an artificially induced high altitude were 3-5% higher than those at a low altitude. The differences were significant, both statistically (p<0.05) and substantively. The average LC values were neither statistically significant (p>0.05) nor substantively significant. Conclusions:Not-adapted youth elite cross-country skiers have higher HR at artificially induced high altitudes (2000 m ASL) during the test on SkiErg ® compare to the same load in lowland (500 m ASL). The absence of alterations in the average LC confirms that it is more appropriate to monitor the HR for altitude acute effect assessment and employ LC only for verification. For the management of endurance sports training at high altitude our research confirmed that exercise must respect the principles of acclimatization processes.

This study aimed to analyse the influence of defensive team variables on goals conceded in the first division of the Spanish soccer league (LaLiga) between the 2013-2014 and 2022-2023 seasons. Defensive variables from LaLiga's first division across ten seasons (2013-2014 to 2022-2023) were analysed, including all teams that participated during this period. Thirty-three defensive metrics were selected from the Wyscout database, focusing on team performance. The selection process was conducted by three independent researchers. Moderate positive correlations were found between goals conceded and opponents' ball touches (r = 0.410), opponent ball possession (r = 0.358), and opponents' ball touches in various field areas (0.304 ≤ r ≤ 0.381). Defensive errors also correlated positively, while unsuccessful attempts to challenge a dribbling opponent showed a weak negative correlation. Regression analysis identified that opponents' ball touches and shots conceded were the most significant factors, explaining 25.5% of the variance in goals conceded. The findings suggest that limiting opponents' touches, possession, and shots is essential in minimizing goals conceded, as greater opponent control correlates with increased scoring chances. Defensive lapses undermine overall performance, while certain set-piece and defensive actions showed a limited effect. Developing strategies that reduce opponent control and improve challenge success rates is crucial. Further research is recommended across different leagues and categories to enhance understanding of defensive tactics in soccer.