Search Results (92)

This longitudinal study aimed to examine the in-season variations in morphological, cardiorespiratory, muscular, and motor fitness components in junior male basketball players during an 8-month competitive season. Eighteen male basketball players (16.56 ± 0.90 years) were tested at three time points (T1, T2, T3). Assessed variables included body fat (BF), fat-free mass (FFM), muscle mass (MM), total body water (TBW), maximal oxygen uptake (VO₂max), final running speed in the 30-15 Intermittent Fitness Test (VIFT), maximum and average heart rate (HRmax, HRavg), squat jump (SJ), countermovement jump with arm swing (CMJmax), drop jump (DJ), 20 m sprint with 5 m and 10 m splits, T-test (TT), and Lane Agility Drill (LAD). Significant improvements were observed in body mass (T1–T3, p = 0.002; T2–T3, p = 0.039), along with reductions in BF (T1–T2 and T1–T3, p < 0.05) and increases in FFM and MM (especially T2–T3, p < 0.05). VO₂max increased significantly from T1 to T2 and T3 (p < 0.01), while HRaverage decreased across all intervals (p < 0.001), and HRmax declined slightly from T1 to T3 (p = 0.031). VIFT improved significantly between T1 and both T2 and T3 (p < 0.001). Measures of explosive strength (SJ, CMJmax, DJ) and agility (TT, LAD) showed consistent improvement across the season (p < 0.001), with moderate gains from T2 to T3 (p < 0.01 for SJ). These findings suggest meaningful physical and physiological adaptations during the competitive season, highlighting the importance of structured and continuous training throughout critical phases of athletic development in junior basketball players. Full article

Brazilian jiu-jitsu (BJJ) is a combat sport that requires intermittent high-intensity actions, strong technical skills, strength, and aerobic capacity. Yet, there is limited evidence of validated sport-specific field protocols. This study aimed to determine the validity, reliability, and sensitivity of the BJJ Cardiorespiratory Fitness Test (BJJ-CRFT). Twenty-three trained practitioners (20 men and 3 women; age 34.4 ± 7.6 years) performed a cardiopulmonary exercise test on a treadmill and completed the BJJ-CRFT on two occasions, one week apart. Construct validity was examined using receiver operating characteristic (ROC) analysis, while concurrent validity was tested against maximal oxygen uptake (VO₂max) and maximal aerobic speed (MAS). Intra-session reliability was determined through the intraclass correlation coefficient (ICC) and the coefficient of variation (CV%). Main results showed a good discriminative ability (ROC: 0.82; 95% CI: 0.64–0.99, p = 0.001). Total repetitions in the BJJ-CRFT showed a large positive correlation with VO₂max (r = 0.66; 95% CI: 0.35–0.85, p = 0.0006) and a very large positive correlation with MAS (r = 0.72; 95% CI: 0.44–0.87, p = 0.0001). Key performance metrics, including guard passes and test duration, demonstrated excellent relative reliability (ICC = 0.99) and good absolute reliability (CV% = 4.4% and 3.6%), being sensitive to small changes. These results confirm that the BJJ-CRFT is a valid, reliable, and sensitive field test for monitoring aerobic adaptations and guiding training prescription in BJJ. Full article

Background: The off-season is often characterized by a significant decrease or even a complete cessation of training. If this reduction is not planned properly, it can result in detraining. Despite numerous studies examining the effects of HIIT in football players, its specific role in mitigating detraining and maintaining aerobic and anaerobic performance during the off-season in adolescent female football players remains underexplored. Therefore, this study evaluated the effects of a 4-week off-season high-intensity training (HIIT) program on aerobic performance level and sprint endurance ability in Under-15 (U-15) female football players. Methods: Fifteen U-15 female football players from a professional club completed an experimental protocol consisting of two HIIT formats: Small-Sided Games (SSGs) and Repeated Sprint Training (RST), each performed twice weekly. Before and after the intervention period, participants performed the Yo-Yo Intermittent Recovery Level 1 (YYIR1) test to gauge aerobic performance and the 30-seconds sprint test to assess sprint endurance. The internal training load was monitored via heart rate (HR) and blood lactate concentration ([La]⁺), while external training load metrics included the total distance (TD), moderate-speed distance (MSD), high-speed distance (HSD), acceleration distance (≥3 m·s⁻²; ACC), and deceleration distance (≤−3 m·s⁻²; DEC). Results: YYIR1 improved by 57% (p = 0.0001; d = 1.12; 95% CI: 121.94–224.71) and the 30-s test performance increased by 13% (p = 0.004; d = 0.91; and 95% CI: 14.46–25.53) following the intervention period. A very large correlation between time spent at 90–95% HRmax and the 30-s test (r = 0.90, p = 0.0001) and YYIR1 (r = 0.81, p = 0.0001) performance was observed. Very large and nearly perfect correlations between DHS and YYIR1 (r = 0.82, p = 0.0001) and the 30-s test performance (r = 0.94, p = 0.0001), respectively, were found. Conclusions: In U-15 female football players, a four-week off-season HIIT program improved both aerobic performance and sprint endurance ability, indicating that a HIIT regime attenuates the off-season detraining, thus supporting a better-conditioned return to play. Coaches may implement 4-week high-intensity off-season programs to enhance aerobic performance and start the pre-season with a satisfactory level of aerobic fitness and sprint endurance. Full article

Background: Basketball is characterized as a high-intensity, intermittent sport that places considerable demands on the cardiorespiratory, neuromuscular, and mechanical systems. These physiological requirements are modulated by contextual variables and the athlete’s stage of biological maturation, both of which significantly influence physical fitness outcomes. Consequently, it is imperative to employ age- and development-specific assessment protocols. Objectives: This study aimed to evaluate the differences in physical fitness across competitive categories and to explore the interrelationships among the various physical assessment tests. Twenty-four male players (U14 = 12; U16 = 12) participated in this research. Methods: Athletes were monitored using WIMUPRO inertial measurement units and completed the SBAFIT test battery to evaluate physical fitness parameters. Statistical analyses included both inferential and correlational approaches, with effect sizes calculated for all relevant variables. The independent variable was the competitive age category of the players. Results: The results indicated notable differences in physical performance between developmental groups, primarily attributed to biological maturation. Significant disparities were observed in measures of aerobic capacity, linear speed, agility, and centripetal force. Conclusions: The comparative nature of this study across developmental categories offers novel insights and practical implications for talent development and training optimization. Full article

Background: Adolescent obesity represents a global public health issue, with an urgent need for tailored intervention strategies, particularly in school settings. Objectives: This study investigated the impact of adapted basketball training—with and without video summaries—on BMI, fitness, motivation, and technical skills in adolescents with moderate obesity. Methods: Fifty-five participants were randomly assigned to one of three instructional modalities—a modified basketball program enriched with video summaries (ADAPT + VID), a modified program without videos (ADAPT), and a traditional program (CONT)—and completed an eight-week intervention. Before (T0) and after (T1) the intervention, participants in all three groups underwent testing to assess: (i) anthropometric measurements (BMI), (ii) technical accuracy (passing, dribbling, and shooting), (iii) physical fitness using the Intermittent Fitness Test 15-15 (Spartacus Test), and (iv) motivation using the Situational Motivation Scale. Results: Assessments revealed significant improvements in the ADAPT + VID group, with notable reductions in BMI (d = 0.25, p < 0.05), enhanced physical fitness (d = 0.19, p = 0.002), and improved performance in passing (d = 1.42, p < 0.001), dribbling (d = 1.30, p < 0.001), and free-throw shooting (d = 0.80, p < 0.001). Moreover, a significant increase in intrinsic motivation (d = 1.18, p < 0.001) and a reduction in amotivation (d = 1.12, p < 0.001) were observed. Conclusions: These findings suggest that incorporating pedagogical video summaries into an adapted basketball program may effectively improve physical health, motor skills, and motivation among adolescents with moderate obesity. Full article

Objetives: This study aimed to (1) describe and compare the external physical requirements of international cerebral palsy (CP) football players during training sessions and official matches at the 2024 IFCPF World Cup, and (2) analyze the relationships between standardized field-based physical performance tests and the physical requirements recorded in both contexts. Methods: Twelve international outfield players from the Spanish national CP football team were monitored throughout the tournament. Physical performance was evaluated two weeks prior using 5-m and 30-m sprints, a Modified Agility Test (MAT), a dribbling test, and the 30–15 Intermittent Fitness Test (vIFT). Match and training physical requirements were assessed using inertial devices, including total and relative distances, velocity metrics, and acceleration/deceleration outputs. Results: Matches imposed significantly greater demands than training sessions in terms of peak velocity, total distance per minute, and distance at moderate (>12–18 km/h) and high (>18 km/h) intensities (t = 2.79 to 8.06; p = 0.01; ES(d) = 0.50 to 1.45). Training sessions exhibited greater variability in load while match requirements were consistent across games. Performance in the MAT and dribbling tests correlated with several physical indicators in both training and competition. In contrast, vIFT and sprint tests showed limited associations, especially with match variables. Conclusions: Match play elicits higher and more stable physical requirements than training. The MAT and dribbling tests appear to be ecologically valid tools for assessing functional readiness in CP football. These findings support the integration of specific physical tests and tailored training designs to better replicate the competitive requirements of international CP football. Full article

Background/Objectives: The aim of this study was to investigate the acute effect of isometric and plyometric combined activation prior to the endurance performance assessed with the 30-15 Intermittent Fitness Test (30-15 IFT) and cardiovascular parameters. Methods: In this crossover study the data of 14 elite female soccer players aged 22.1 ± 2.9 years were assessed. The conditioning activity (CA) consisted of three sets of five seconds of maximal mid-thigh pull (IMPT), and peak force was measured, and four countermovement jumps were performed. Contact time, jump height, and reactive strength index (RSI) were assessed. Ninety seconds of rest between the sets was performed. Then, 7 min after the CA, the 30-15 IFT was performed. Results: One-way repeated measures (RM) ANOVA showed that performance during the CA did not decrease; what is more, it improved in RSI (p < 0.01). Further, paired samples t-test showed that the performance in the IFT did not change, whereas training impulse (TRIMP) was increased after CA (p = 0.039, ES = 0.61), thus the Bayesian paired test yielded only anecdotal evidence in favor of the alternative hypothesis (BF₁₀ = 1.92; error = 2%). Conclusions: The improvement in CA suggests potentiation rather than fatigue. However, the unchanged performance alongside a modest TRIMP increase should be interpreted with caution, as TRIMP alone provides a limited assessment of physiological cost. Therefore, while the applied protocol did not enhance endurance performance, further research using multiple physiological markers is needed to clarify its impact on internal load and overall efficacy. Full article

Background/Objectives: Athletic performance matters for athletes and fitness enthusiasts. Scientific dietary intervention may boost athletic performance alongside training. Intermittent fasting, like time-restricted fasting (TF), may enhance metabolic health. NAD⁺ supplement nicotinamide mononucleotide (NMN) improves mitochondrial activity. Both potentially boost athletic performance. However, whether TF combined with NMN treatment can further enhance athletic ability is unclear. Methods: Healthy Kunming mice were utilized to test the effects of NMN and TF on the athletic performance of mice. To simulate the in vivo state and further verify the role of TF and NMN, low glucose combined with NMN was used to intervene in C2C12 cells. The exercise capacity of mice was evaluated through motor behavior experiments. At the same time, blood gas analysis and kit tests were used to assess oxygen uptake capacity and post-exercise oxidative stress levels. Muscle development and mitochondrial function were examined through gene expression, protein analysis, and enzyme activity tests, and the distribution of intestinal microbiota and short-chain fatty acid content were also analyzed. Results: The results show that TF combined with NMN improved mitochondrial dynamics and biosynthesis, mitochondrial respiratory function, and oxidative metabolism. Then, the intervention enhanced mice’s endurance, limb strength, motor coordination, and balance and reduced oxidative damage after exercise. Moreover, TF combined with NMN significantly increased the gut microbiota diversity and upregulated Ruminococcus, Roseburia, and Akkermansia in intestinal bacteria and short-chain fatty acids, which are associated with athletic performance. Conclusion: TF combined with NMN enhanced mitochondrial function, improved energy metabolism, modulated the gut microbiota and short-chain fatty acids, and affected muscle fiber transformation, ultimately leading to an overall improvement in exercise performance. These findings provide a theoretical framework for expanding the application of NMN and TF in kinesiology. Full article

Cortisol is an important marker of hypothalamic-pituitary-adrenal function and follows robust circadian and diurnal rhythms. However, biomarker sampling protocols can be labor-intensive and cost-prohibitive. Objectives: Explore analytical approaches that can handle differing biological sampling frequencies to maximize these data in more detailed and time-dependent analyses. Methods: Healthy adult males [N = 8; 26.1 (±3.1) years; 176.4 (±8.6) cm; 73.1 (±12.0) kg)] completed two 24 h admissions: one at rest and one including a high-intensity exercise session on the cycle ergometer. Serum and salivary cortisol were sampled every 60 and 120 min, respectively. Six alternative sampling profiles were defined by downsampling from the observed data and creating two intermittent sampling profiles. A polynomial (1–6 degrees) validation process was performed, and interpolation was conducted to match the observed data. Model fit and performance were assessed using the coefficient of determination (R²) and the root mean square error (RMSE), as well as an examination of the equivalence, via two one-sided t-tests (TOST), of 24 h cortisol output between the observed and interpolated data. Results: Mean serum cortisol output was higher than salivary cortisol (p < 0.001), and no effect was observed for condition (p = 0.61). Second- and third-degree polynomial regressions were determined to be the optimal models for fitting salivary. TOST tests determined that serum data and estimated 24 h output from these models (with interpolation) provided statistically similar estimates to the observed data (p < 0.05). Conclusions: Second- and third-degree polynomial fits of salivary and serum cortisol provide a reasonable means for interpolation without introducing bias into estimates of 24 h output. This allows researchers to sample biomarkers at biologically relevant frequencies and subsequently match necessary sampling frequencies during the data processing stage of various machine learning workflows. Full article

Background/Objectives: This study aimed to determine the impact of the daily consumption of kefir on the gut microbiome, body composition, and athletic performance of professional female soccer players. Methods: The participants encompassed 21 females aged 18–29 years who were assigned to one of the two groups: the experimental group, which comprised females who consumed 200 mL of kefir daily for 28 days, and the control group, which comprised females who continued with their normal diet. Anthropometric measurements, dietary intake, the composition of the gut microbiome through 16S rRNA gene sequencing, and an athletic performance test known as the 30-15 Intermittent Fitness Test were performed before and after the intervention. Results: The results of this study revealed that the consumption of kefir increased the microbial diversity (Shannon and Chao1 indices), wherein a significant increase was noted in the abundance of Akkermansia muciniphila and Faecalibacterium prausnitzii, microorganisms that regulate energy metabolism and have anti-inflammatory effects. Furthermore, the athletic performance variables, including VO₂max (mL.kg⁻¹.min⁻¹) and finishing speed (km/h), were strongly related to the abundance of these short-chain fatty acid-producing bacteria. A link between the microbiota profile and the dietary intake of fiber and protein as well as the body composition measurements was also established. Conclusions: This study indicated that kefir consumption can positively affect the gut microbiota, which could in turn affect the athletes’ performance. Therefore, to determine the effects of kefir as a functional food in sports nutrition over a longer period, more research should be conducted. Full article

Background: Children with motor delays often experience challenges in health-related fitness, but the impact on running skills remains unclear. Previous research has shown that children with motor coordination problems have lower cardiorespiratory fitness, muscle strength, endurance, and higher body weight compared to peers. Few studies have examined anaerobic capacity, muscular power, endurance, running performance, and fatigue in children with developmental coordination disorder (DCD). This study aims to compare repetitive running and running-induced fatigue in typically developing children and those with varying degrees of motor coordination problems. Methods: Groups were classified using the Movement Assessment Battery for Children, second edition (MABC-2), as probably having DCD (p-DCD, ≤5th percentile, age 9.7 (SD 1.6), n = 141), at risk for DCD (r-DCD, 6th–16th percentile, age 9.9 (SD1.6), n = 160), and typically developing (TD, >16th percentile, age 9.6 (SD 1.6), n = 191). Anaerobic fitness and fatigue were assessed using the Children’s Repetitive and Intermittent Sprinting Performance test (CRISP), while lower and upper body muscular strength, running, and agility were measured with the performance and fitness (PERF-FIT) test battery Power and Agility subscale. Age groups (6–9 and 10–12 years) were analyzed to determine when performance deficits emerged. Results: The p-DCD group was significantly slower, had less power, and fatigued more than the r-DCD and TD children (p < 0.01). This was already clearly the case in the 6–9-year-olds, who slowed down already after the first runs, while the older poorly coordinated children started slower than their peers and showed a more gradual decrease in performance over the runs. Conclusions: Moderate coordination differences between r-DCD and TD children did not significantly impact fatigue, but p-DCD children exhibited greater fatigue due to overestimating their start speed, higher body weight, lower power, and reduced agility, especially in younger age groups. (Too) High starting speed, especially in the younger less coordinated children (p-DCD), is likely to lead to more fatigue. Full article

Background/Objectives: Physical fitness in youth soccer impacts individual and team performance through the specific demands that must be met on the field. Therefore, this study aimed to characterize and identify youth soccer players with regard to the roles they play on the field. Material and Methods: A cross-sectional study was designed to characterize and identify the physical fitness levels of youth soccer players using previously validated measurement tests. A total of 36 players were evaluated (15 defenders and 24 attackers) using various physical fitness tests: Squat Jump (SJ), Countermovement Jump (CMJ), Single-leg Countermovement Jumps (SLCMJs), COD-Timer 5-0-5, Speed (5, 10, 15, and 20 m), Yo-Yo Intermittent Recovery Test Level I (YYIR1), and Running-Based Anaerobic Sprint Test (RAST). The data were confirmed using the Shapiro–Wilk test. Effect sizes were obtained using the Rank-Biserial coefficient, and, to identify the profiles of attackers and defenders, principal component analysis (PCA) was employed. Results: For the strength variables, attackers obtained better results than defenders in the variable flight time in the SJ (p = 0.03; R-b = −0.33) and contact time (%) in the SLCMJ test (p = 0.04; R-b = −0.33). Meanwhile, defenders achieved better results than attackers in the SLCMJ test for the variable flight time (%) (p = 0.01; R-b = 0.33) and breaking angle (A°) in the Nordic Hamstring (p = 0.01; R-b = 0.33). The results showed differences according to the players’ roles. Three principal components were identified for both attackers and defenders. The PC1 for attackers considered variables of strength, asymmetry, change of direction, and power. PC2 only considered strength and power variables. PC3 considered variables of strength, speed, endurance, and power. For defenders, PC1 considered strength, asymmetry, and power. PC2 analyzed variables of strength, asymmetry, change of direction and power. Finally, PC3 only grouped speed variables. Conclusions: Although youth soccer positions involve offensive and defensive roles, this study reveals differences in certain physical fitness variables. Therefore, it is necessary to tailor training tasks according to the specificity of the playing position, in line with the systems of play used and the predominance of the role that players occupy, whether in defense or attack. Full article

This study examines the subjective attributes that coaches consider most important for identifying and developing the talent of junior élite football players. It also explores whether players’ physical fitness efficiency moderates these attributes and influences playing time during the regular season. Forty-three junior élite football players and four Italian Serie A club coaches participated in the study, contributing their unique perspectives and experiences. Players’ physical fitness was assessed using the Yo-Yo Intermittent Recovery Level 1 test, while coaches rated players’ abilities through a structured questionnaire. A significant positive relationship was found between ’understanding of the game and position on the field’ and total playing time (t = 3.498, p < 0.01, β = 0.953). Physical efficiency further strengthened this relationship when players’ fitness levels were average (b = 0.624, p < 0.001) and one standard deviation above the mean (b = 0.891, p < 0.001). These findings highlight the importance of tactical awareness in earning playing time and suggest that physical fitness enhances the effect of cognitive abilities on performance. This study provides insights into how coaches assess talent and underscores the value of integrating physical and tactical development in youth football, providing a testament to the power of collaboration in advancing our understanding of talent identification in sports. Full article

Background: the purpose of this study was to analyze the reliability of a field-based fitness test battery in young trained football players, according to biological age. Methods: 197 young trained football players (12–19 years old) participated in the study. We measured anthropometric measurements (i.e., height, sitting height, length leg, and body mass), a bilateral vertical jumping test (CMJ), a progressive loading test of squats and hip thrust, acceleration and speed tests (10 m and 30 m sprint tests), a change-of-direction ability test (V–cut test), and a cardiorespiratory fitness test (30–15 intermittent fitness test). Statistical data are shown as the mean ± standard deviation by PHV group in tests and retests. Test reliability was assessed through the intraclass correlation coefficient (ICC), with an ICC above 0.9 being considered high. To evaluate accuracy and repeatability, standard error of measurement, coefficient of variation, and minimum detectable change at 90% were determined and Bland–Altman diagrams were used, establishing a statistical significance of p < 0.05. Results: All of the tests showed non-significant differences between the test and retest in the pooled sample (p > 0.05). Furthermore, all of them presented a trivial effect size (<0.2) and high intraclass correlation coefficients (>0.9), which indicates the high reproducibility of the tests, despite some of them presenting a significant difference between trials (i.e., the CMJ, 10 m sprint, V–cut, and squat tests). Low measurement errors were found for all tests (coefficient of variation [CV] = 4.39–9.39), except for the CMJ and the progressive loading test for squat and hip thrust exercises (CV = 12.2–21.11). Similar results were found irrespective of biological age group. Conclusions: All tests were reliable for the pooled sample as well as for the biological age groups. Full article

Using drone cells to optimize Radio Access Networks is an exemplary way to enhance the capabilities of terrestrial Radio Access Networks. Drones fitted with communication and relay modules can act as drone cells to provide an unobtrusive network connection. The multi-drone-cell placement problem is solved using adapted Dispersive Flies Optimization alongside other meta-heuristic algorithms such as Particle Swarm Optimization and differential evolution. A home-brewed simulator has been used to test the effectiveness of the different implemented algorithms. Specific environment respective parameter tuning has been explored to better highlight the possible advantages of one algorithm over the other in any particular environment. Algorithmic diversity has been explored, leading to several modifications and improvements in the implemented models. The results show that by using tuned parameters, there is a performance uplift in coverage probability when compared to the default meta-heuristic parameters while still remaining within the constraints implied by the problem’s requirements and resource limitation. This paper concludes by offering a study and comparison between multiple meta-heuristic approaches, investigating the impact of parameter tuning as well as analyzing the impact of intermittent restarts for the algorithms’ persistent diversity. Full article