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The aim was to analyse the consequences of a congested schedule (due to the COVID-19 lockdown) on creatine kinase (CK) in elite football players using GPS tracking technology. A total of 17 elite football players were monitored in training and competition with a global positioning system. Variables including total distance, high-intensity distance, and distance acceleration and deceleration were analysed. Different measurements of serum creatine kinase (CK) concentration were performed on match day (MD) and at 24 h (MD+1), 48 h (MD+2), and 72 h (MD+3) after each match to study the muscle damage of each individual player caused during the match. The results showed a significant increase in physical demands in training (in relative terms regarding the match) at MD+3 compared to MD+1 and MD+2. Furthermore, at +72 h, CK decreases to a value almost the same as that before MD. On the other hand, the players with lower demands for high-intensity actions in the match showed a higher reduction in the concentration of CK at MD+3 compared to MD+1 and MD+2 (p < 0.05). It became evident that players with high-intensity demand and a high number of accelerations and decelerations need more time to assimilate the match load and can remain in a state of muscle fatigue for up to 3 days. In addition, a congested schedule can lead to a state of chronic fatigue in elite football players, limiting physical performance and possibly increasing the potential risk of injury for football players. [ABSTRACT FROM AUTHOR]

Airtime is crucial for high-rotation tricks in snowboard halfpipe performance, significantly impacting trick difficulty, the primary judging criterion. This study aims to enhance the detection of take-off and landing events using inertial measurement unit (IMU) data in conjunction with machine learning algorithms since manual video-based methods are too time-consuming. Eight elite German National Team snowboarders performed 626 halfpipe tricks, recorded by two IMUs at the lateral lower legs and a video camera. The IMU data, synchronized with video, were labeled manually and segmented for analysis. Utilizing a 1D U-Net convolutional neural network (CNN), we achieved superior performance in all of our experiments, establishing new benchmarks for this binary segmentation task. In our extensive experiments, we achieved an 80.34 % lower mean Hausdorff distance for unseen runs compared with the threshold approach when placed solely on the left lower leg. Using both left and right IMUs further improved performance ( 83.37 % lower mean Hausdorff). For data from an algorithm-unknown athlete (Zero-Shot segmentation), the U-Net outperformed the threshold algorithm by 67.58 %, and fine-tuning on athlete-specific (Few-Shot segmentation) runs improved the lower mean Hausdorff to 78.68 %. The fine-tuned model detected takeoffs with median deviations of 0.008 s (IQR 0.030 s), landing deviations of 0.005 s (IQR 0.020 s), and airtime deviations of 0.000 s (IQR 0.027 s). These advancements facilitate real-time feedback and detailed biomechanical analysis, enhancing performance and trick execution, particularly during critical events, such as take-off and landing, where precise time-domain localization is crucial for providing accurate feedback to coaches and athletes. [ABSTRACT FROM AUTHOR]

(1) Background: This case study analyzed the successful performances of female gymnasts in the finals of the 39th and 40th World Cup in Maribor (SLO). The aim was to identify variations in their execution of the Clear Hip Circle to Handstand (CHCH) on uneven bars based on kinematic parameters. (2) Methods: This study involved elite female gymnasts from the 39th (n = 5, age: 17 ± 6 months) and 40th (n = 8, age: 17.5 ± 6 months) World Cups, totaling 13 gymnasts. Kinematic analysis was performed on 15 successful routines using the Ariel Performance Analysis System (Ariel Dynamics Inc., San Diego, CA). The analysis focused on 16 anthropometric reference points and 8 body segments, including the body mass center of gravity (CG). The main reference points analyzed were the hip joint, the shoulder joint, and the CG along the xy-axes. Trajectory, velocity, angle, and angular velocity of the hips and shoulders were calculated. Pearson correlation analysis was employed to assess the relationships between the kinematic variables. (3) Results: High intercorrelations between the reference points along the xy-axes (0.81–0.99) and optimal movement velocity were found. Dispersed results were observed for kinematic parameters of angle (0.10–0.16) and angular velocity of the hip joints (0.60–1.00), with similar dispersions for shoulder joints (0.51–1.00). Three distinct techniques were identified: (1) stretched body with minimal hip joint flexion throughout; (2) extended body with a short, quick hip joint extension during shoulder movement; and (3) hyperextension in the hip joint. (4) Conclusions: The kinematic analysis revealed three different performance styles of the CHCH among finalists. These variations in technique do not affect the success of the performance. This research contributes to a better understanding of the technique but does not prefer one style over another. [ABSTRACT FROM AUTHOR]

Fatigue specifically affects the force production capacity of the working muscle, leading to a decline in athletes' performance. This study investigated the impact of fatigue on ankle flexor muscle activity and ground reaction forces (GRFs) in elite table tennis players, with a focus on the implications for performance and injury risk. Twelve elite male table tennis athletes participated in this study, undergoing a fatigue protocol that simulated intense gameplay conditions. Muscle activity of the soleus (SOL) and gastrocnemius lateralis (GL) muscles, heel height, and GRFs were measured using a combination of wireless electromyography (EMG), motion capture, and force plate systems. Results showed a significant decrease in muscle activity in both legs post-fatigue, with a more pronounced decline in the right leg. This decrease in muscle activity negatively affected ankle joint flexibility, limiting heel lift-off. Interestingly, the maximal anteroposterior GRF generated by the left leg increased in the post-fatigue phase, suggesting the use of compensatory strategies to maintain balance and performance. These findings underscore the importance of managing fatigue, addressing muscle imbalances, and improving ankle flexibility and strength to optimize performance and reduce the risk of injuries. [ABSTRACT FROM AUTHOR]

The objectives of this study were to compare the effects of two in-season velocity loss training methods (VBT) on performance outcomes and to evaluate the effects of velocity-based training compared to traditional resistance training (TRT) on performance outcomes in young elite soccer players. VBT utilized the same relative load but varied in the extent of velocity loss during the set: 15% (VL15%) and 30% (VL30%). Thirty-four players were recruited and randomly distributed into three groups: the VL15% group (n = 12; age = 18.50 ± 0.67 years; stature = 183.41 ± 4.25 cm; body mass = 75.08 ± 5.57 kg), the VL30% group (n = 11; age = 17.91 ± 0.60 years; stature = 181.21 ± 6.56 cm, body mass = 73.58 ± 6.22 kg), and the traditional strength training group TRT (n = 11; age = 18.14 ± 0.74 years; stature = 182.17 ± 5.52 cm; body mass = 74.86 ± 6.68 kg). Alongside regular soccer sessions and matches, the groups underwent a four-week (2 sesions per week) resistance training intervention with back squats involved. Changes in leg strength (SQ1RM), 20 m sprint time (SPR 20 m), countermovement jump height (CMJ), reactive strength index (RSI), and change of direction (COD) from before and after were evaluated using a 3 × 2 ANOVA. While no significant interaction was found for SQ1RM and SPR20, all of the groups showed significant pre to post improvements. Significant interactions were observed for CMJ (F = 38.24, p = 0.000), RSI (F = 8.33; p = 0.001), and change of direction agility test (COD) (F = 3.64; p = 0.038), with a post hoc analysis showing differences between the VL15 (6.0%) and TRT (1.7%) groups (p = 0.034); VL15 (12.2%) and VL30 (3.2%) groups (p = 0.004); VL15 and TRT (0.4%) (p = 0.018); VL15 (2.4%) and VL30 (1.5%) (p = 0.049); and between the VL15 and TRT (0.4%) groups (p = 0.015). Four weeks of VL15% training during the season induced similar strength increases to VL30% and TRT, superior improvements in RSI and COD compared to VL30%, and superior improvements in CMJ, RSI, and COD tests compared to TRT. Thus, incorporating the VL15% training method may be recommended to improve power-related performance metrics in elite young soccer players. [ABSTRACT FROM AUTHOR]

Team sports require athletes' exceptional perceptual-cognitive skills, such as anticipation and decision-making. Perceptual-cognitive training in laboratories aims to enhance these abilities. However, its effectiveness in real-game performance remains controversial, necessitating a systematic review and meta-analysis to determine optimal training methods. Following the PRISMA guidelines, we searched databases (e.g., PubMed, WOS, Scopus, and EBSCO) for relevant studies published before November 2023, assessed study quality, extracted important characteristics, and conducted a meta-analysis using Stata 15.1. This study was registered in PROSPERO (CRD42023494324). A total of 22 quantitative studies involving 45 effect sizes were included. Perceptual-cognitive training positively influenced elite athletes' anticipation and decision-making. However, its transfer effect on real-game performance improvement (ES = 0.65) was inferior to laboratory performance improvement (ES = 1.51). Sub-group analyses indicated that the effects of training interventions varied based on stimulus presentation and intervention duration. Based on our findings, we concluded that while perceptual-cognitive training improved on-court performance, its transfer effects were limited. To maximize effectiveness, future interventions should use virtual reality to present training stimuli and incorporate participants' sport-specific responses to reflect real-game scenarios. [ABSTRACT FROM AUTHOR]

This study investigated the long-term cardiovascular effects of coronavirus disease (COVID-19) in elite male athletes by comparing the heart rate variability (HRV), arterial stiffness, and other cardiovascular parameters between those with and without prior COVID-19 infection. Methods: This cross-sectional study evaluated 120 elite male athletes (60 post COVID-19, 60 controls) using anthropometric measurements, body composition analysis, pulmonary function tests, HRV analysis, arterial stiffness assessments, hemodynamic monitoring, and microcirculatory function tests. Results: Athletes post COVID-19 showed significantly higher lean mass (p = 0.007), forced vital capacity (p = 0.001), and forced expiratory volume in 1 s (p = 0.007) than controls. HRV parameters did not significantly differ between the groups. Post-COVID-19 athletes exhibited peripheral vascular resistance (p = 0.048) and reflection index (p = 0.038). No significant differences were observed in the blood pressure, cardiac output, oxygen saturation, or microcirculatory oxygen absorption. Conclusions: Elite male athletes showed notable cardiovascular resilience after COVID-19, with only minor differences in vascular function. The maintained cardiac autonomic function and improved lung parameters in post-COVID-19 athletes suggests an adaptive response. These findings support the cardiovascular health of elite athletes following COVID-19 but emphasize the importance of continued monitoring. [ABSTRACT FROM AUTHOR]

Assessing respiratory frequency (fR) is practical in monitoring training progress in competitive athletes, especially during exercise. This study aimed to validate a new wearable chest strap (wCS) to estimate fR against ergospirometry as a criterion device in soccer players. A total of 26 elite professional soccer players (mean [standard deviation]: 23.6 [4.8] years; 180.6 [5.7] cm; 77.2 [5.4] kg) from three Italian Serie A League teams participated in this cross-sectional study. The sample included attackers, midfielders, and defenders. fR was assessed during a maximal cardiopulmonary exercise test (CPET) on a treadmill using (i) a breath-by-breath gas exchange analyzer (Vyntus® CPX, Vyaire Medical) and (ii) a novel wCS with sensors designed to assess breath frequency following chest expansions. Pearson's correlation coefficient (r), adjusted coefficient of determination (aR2), Bland–Altman plot analysis, and Lin's concordance correlation coefficient (ρc) were used for comparative analysis (correlation and concordance) among the methods. The repeated measures correlation coefficient (rrm) was used to assess the strength of the linear association between the methods. The intraclass correlation coefficient (ICC) and the Finn coefficient (rF) were used for inter-rater reliability. All statistical analyses were performed within the R statistical computing environment, with 95% confidence intervals (95% CIs) reported and statistical significance set at p < 0.05. A total of 16529 comparisons were performed after collecting the CPET data. The robust time series analysis with Hodges–Lehmann estimation showed no significant differences between both methods (p > 0.05). Correlation among devices was statistically significant and very large (r [95% CI]: 0.970 [0.970, 0.971], p < 0.01; aR2 [95% CI]: 0.942 [0.942, 0.943], p < 0.01) with strong evidence supporting consistency of the new wCS (BF10 > 100). In addition, a high concordance was found (ρc [95% CI]: 0.970 [0.969, 0.971], bias correction factor: 0.999). VyntusTM CPX, as a standard criterion, showed moderate agreement with wCS after Bland–Altman analysis (bias [95% lower to the upper limit of agreement]; % agree: 0.170 [−4.582 to 4.923] breaths·min−1; 69.9%). A strong association between measurements (rrm [95% CI]: 0.960 [0.959, 0.961]), a high absolute agreement between methods (ICC [95% CI]: 0.970 [0.970, 0.971]), and high inter-rater reliability (rF: 0.947) were found. With an RMSE = 2.42 breaths·min−1, the new wCS seems to be an valid and reliable in-field method to evaluate fR compared to a breath-by-breath gas exchange analyzer. Notwithstanding, caution is advised if methods are used interchangeably while further external validation occurs. [ABSTRACT FROM AUTHOR]

Objective: To conduct a longitudinal retrospective analysis, explore the relationship between success at peak performance age and the number of different race distances athletes competed in each year (within-sport distance variety), and compare the dose–time effect of this distance variety throughout the development process between male swimmers and track runners. Methodology: Male swimmers (n = 6033) and track runners (n = 19,278) still competing at peak performance age were ranked, and the number of different race distances was extracted retrospectively for each year until early junior age (13–14-year-old category) from the databases of the European Aquatics and World Athletics federations. Firstly, correlation analysis determined the relationship between ranking at peak performance age and distance variety. Secondly, Poisson distribution provided the probability and dose–time effect of distance variety for becoming an international-class athlete at peak performance age. Results: Generally, correlation analysis revealed low coefficients (r ≤ 0.22) but significant effects (p < 0.001) for larger distance variety and success at peak performance age. Poisson distribution revealed the highest probability of becoming an international-class swimmer when competing in 2–4 race distances at junior age, depending on the primary race distance. The dose–time effect indicated a gradual reduction in the number of race distances as athletes approached peak performance age, narrowing down to 1–2, 2–3, and 3–4 distances for sprint, middle-, and long-distance races, respectively. Track runners exhibited a lower distance variety than swimmers, with a consistent optimum of 1–2 race distances across the age groups. Conclusions: The present findings including data of the most combined race distances for each primary race distance and a comparison between swimming and track running provide new background information to challenge traditional training regimes and help establish new strategies for long-term athlete development. [ABSTRACT FROM AUTHOR]

The training schedule is a factor that influences sports performance optimization. In a sport like soccer, there is often significant disparity in training schedules among different teams within the same club, without considering whether this may affect players' performance. The aim of this study was to describe differences in nutrient intake and body composition in elite youth soccer players from the Spanish league with different training schedules (morning and evening). A cross-sectional study was conducted to determine differences in anthropometric variables and dietary assessment in a sample of Spanish young soccer players. A total of 41 players participated in this study. After comparing the groups according to their training schedule, no differences were observed in body composition between both groups; the evening-night training group showed higher consumption of lipids and saturated fats. In summary, more experimental studies are needed to determine the effects on various health and performance parameters of different training schedules in young population. [ABSTRACT FROM AUTHOR]

Background/Objectives: Myocardial involvement has been observed in athletes following SARS-CoV-2 infection. It is unclear if these changes are due to myocardial damage per se or to an interruption in training. The aim of this study was to assess cardiac function and structure in elite athletes before and after infection (INFAt) and compare them to a group of healthy controls (CON). Methods: Transthoracic echocardiography was performed in 32 elite athletes, including 16 INFAt (median 21.0 (19.3–21.5) years, 10 male) before (t0) and 52 days after (t1) mild SARS-CoV-2 infection and 16 sex-, age- and sports type-matched CON. Left and right ventricular global longitudinal strain (LV/RV GLS), RV free wall longitudinal strain (RV FWS) and left atrial strain (LAS) were assessed by an investigator blinded to patient history. Results: INFAt showed no significant changes in echocardiographic parameters between t0 and t1, including LV GLS (−21.8% vs. −21.7%, p = 0.649) and RV GLS (−29.1% vs. −28.7%, p = 0.626). A significant increase was observed in LA reservoir strain (LASr) (35.7% vs. 47.8%, p = 0.012). Compared to CON, INFAt at t1 had significantly higher RV FWS (−33.0% vs. −28.2%, p = 0.011), LASr (47.8% vs. 30.5%, p < 0.001) and LA contraction strain (−12.8% vs. −4.9%, p = 0.050) values. Conclusions: In elite athletes, mild SARS-CoV-2 infection does not significantly impact LV function when compared to their pre-SARS-CoV-2 status and to healthy controls. However, subtle changes in RV and LA strain may indicate temporary or training-related adaptions. Further research is needed, particularly focusing on athletes with more severe infections or prolonged symptoms. [ABSTRACT FROM AUTHOR]

Background: The focus of this qualitative research was to interview current and retired Gaelic games athletes to ascertain how athletes viewed concussion recognition and management. Methods: A grounded theory methodology design was utilised to investigate concussion recognition and management experiences of a cohort of Gaelic games athletes (n = 22). Data for the study were collected using a semi-structured interview format. Results: Two major themes were identified: (1) an inconsistent identification of concussion as an injury and the absence of standardised procedures for removal from play, and (2) the impact of athlete-driven decision making on concussion management. Concussions were experienced by all the participants on multiple occasions while playing Gaelic games. However, concussion recognition and removal rarely occurred, as many athletes chose not to disclose their injuries or self-managed their concussions. Conclusions: The recognition and management of concussions in Gaelic games are currently inadequate, and they may be posing significant risks to athletes' long-term health. This research highlights the need for more stringent protocols for concussion recognition and removal at pitch side. In addition, Gaelic games require a more objective injury management plan during acute and chronic concussion recovery. [ABSTRACT FROM AUTHOR]

Background/Objectives: Hip strength and range of motion have been compared in soccer players with and without hip and groin pain but only in male footballers or gender-combined samples. In female soccer players, the biomechanics contributing to this injury remain poorly understood compared to other sporting injuries. The aim of the present study is to investigate whether differences exist in adductor and abductor isometric test values and hip joint range of motion between elite female soccer players with longstanding groin pain and injury-free controls. Methods: Ten female elite soccer players with current longstanding hip and groin pain and twenty-five injury-free controls from the same teams were included in the study. Hip adductor and abductor isometric strength were evaluated with a hand-held dynamometer. A bent knee fall-out test was also utilized to examine the hip joint range of motion. Results: A significant difference in abductor isometric test values was observed between the control group (2.29 ± 0.53 N/Kg) and the hip and groin pain group (2.77 ± 0.48 N/Kg; p = 0.018). Furthermore, the injured group showed a decreased adductor/abductor ratio compared to the control group (1.00 ± 0.33 vs. 1.27 ± 0.26; p = 0.013). No differences were observed in the bent knee fall-out test (p = 0.285). Conclusions: Female elite soccer players with current longstanding hip and groin pain exhibited higher abductor isometric strength and lower adductor/abductor ratio compared to non-injured women players. There were no differences in the BKFO test between groups. [ABSTRACT FROM AUTHOR]

This study describes the relationships between different physiological measurements and combinations of critical velocity and performance in elite open-water swimmers. A total of 15 international male open-water swimmers performed a 5 × 200 m front crawl incremental test to estimate maximal aerobic speed (MAS), maximal oxygen consumption (VO2max), the first lactate threshold (VLT1), the second lactate threshold (VLT2), the speed corresponding to 2 mmol/L (V2mmol/L) and to 4 mmol/L (V4mmol/L), and the lactate threshold (VDmax). A 10 km pool trial was also performed to assess swimming performance. Official competition performances in 200, 400, 800, and 1500 m events were collected and were also used to calculate critical velocity (CV) with various combinations of distances. Personal best performances in 1500 m events were 941.76 ± 20.28 s. For the 10 km trial, performance was strongly correlated to VLT1 and moderately to V2mmol/L (r = 0.73 and 0.67, respectively). For the 400, 800, and 1500 m events, strong correlations were observed for V2mmol/L and V4mmol/L. Moderate correlations with these events were also observed for VLT1 and for VDmax (400 and 800 m only). For long-distance swimmers, assessment with a fixed blood lactate value seems to be a good option to estimate swimming performance in distance events. In addition, 10 km performance seems to be more related to the aerobic threshold than the anaerobic threshold. [ABSTRACT FROM AUTHOR]

This study aimed to determine the effects of technique asymmetry on 500 m straight-track speed skating performance. We analyzed 20 elite skaters, measuring their joint angles, center of mass shift, and times and speeds during the gliding and push-off phases. The technique asymmetry index (ASI) was calculated for each parameter, and paired t-tests were used to compare bilateral asymmetry. Spearman correlation coefficients assessed the relationship between the ASI and both the average straight track speed and overall performance. Significant bilateral asymmetries in the knee, push-off, trunk, and hip angles were found in both male and female participants (p < 0.05). The male participants demonstrated a higher right push-off speed (p = 0.029) and a longer left gliding time (p = 0.048). Significant asymmetry was also observed in the lateral shift of the center of mass during each phase of the straight-track skating gait cycle (p < 0.001). No significant correlation was found between the ASIs and the overall performance (p ≥ 0.067). These findings indicate that while elite speed skaters demonstrated significant bilateral technique asymmetry in straight track skating, these asymmetries did not significantly impact their overall performance. [ABSTRACT FROM AUTHOR]

Background: In elite curling, precise time perception, speed control, and accuracy are critical components of performance. Stroboscopic training enhances visual processing speed, reaction time, motor skill control, and cognitive abilities by challenging the brain to make quick decisions with limited visual information. Purpose: This study aimed to investigate the impact of stroboscopic visual conditions on the key performance aspects of elite athletes in curling to determine whether these effects can be leveraged in long-term training to enhance elite curling performance. Methods: This study involved the participation of 32 national-level male curling athletes (n = 32, age: 19.9 ± 2.2 years, height: 178.0 ± 6.2 cm, body mass: 71.9 ± 10.6 kg, and training age: 2.7 ± 0.9 years). A cross-over controlled experiment was conducted, with participants randomly assigned to either a stroboscopic-first group (n = 16) or a control-first group (n = 16). Each participant completed tests under both stroboscopic and normal visual conditions, including assessments of time perception error, speed control error, and curling accuracy. Paired sample t-tests were employed to analyse performance differences across conditions, and two-factor ANOVA was used to analyse sequence effects. Bonferroni post-hoc tests were used to compare differences if the main effect was significant. Cohen's d was used for two-group comparisons, whereas ηp2 and Cohen's f were used for comparisons involving three or more groups. Results: under stroboscopic conditions, participants experienced increased errors in time perception (p < 0.001, Cohen's d = 1.143), delivery speed control (p = 0.016, Cohen's d = 0.448), and reduced accuracy (p = 0.029, Cohen's d = 0.404). The sequence main effect on speed control error was significant (p = 0.025, ηp2 = 0.081, Cohen's f = 0.297). Conclusions: Stroboscopic visual conditions negatively impacted cognition (especially time perception) and delivery performance focused on speed control and accuracy in elite curling, highlighting the potential and feasibility of using stroboscopic training to enhance elite curling performance. [ABSTRACT FROM AUTHOR]

This study aimed to discuss the differences in technical characteristics between the lunge-style and squat-style jerk techniques and to reveal the adaptability of these techniques for individual weightlifters. A total of 52 attempts by 32 male weightlifters were selected, and the video data were digitized manually using the SIMI Motion 7.50 three-dimensional analysis system. The technical characteristics of the lunge split and squat jerk were fundamentally consistent during the pre-squat, force exertion, and inertia ascent phases. The primary differences between the lunge split and squat jerk techniques were observed during the squatting and support phases, including the vertical descent velocity of the barbell at the end of the squat shoulder-locking phase and the stability angles in the sagittal and coronal axes. The vertical velocity of the barbell at the end of the squat shoulder-locking phase was significantly greater in the squat style (−0.41 ± 0.17 vs. −0.88 ± 0.14) compared to the lunge style (t = 6.393, p < 0.05). The stability angle on the sagittal axis at the end of the squat-supporting phase in the lunge style was significantly greater (46.99 ± 3.23 vs. 13.64 ± 0.51) than that of the squat style (t = 45.639, p < 0.05). [ABSTRACT FROM AUTHOR]

ACTN3 R577X and ACE I/D polymorphisms are associated with endurance exercise ability. This case–control study explored the association of ACTN3 and ACE gene polymorphisms with elite pure endurance in Korean athletes, hypothesizing that individuals with both ACTN3 XX and ACE II genotypes would exhibit superior endurance. We recruited 934 elite athletes (713 males, 221 females) and selected 45 pure endurance athletes (36 males, 9 females) requiring "≥90% aerobic energy metabolism during sports events", in addition to 679 healthy non-athlete Koreans (361 males, 318 females) as controls. Genomic DNA was extracted and genotyped for ACTN3 R577X and ACE I/D polymorphisms. ACE ID (p = 0.090) and ACTN3 RX+XX (p = 0.029) genotype distributions were significantly different between the two groups. Complex ACTN3-ACE genotypes also exhibited significant differences (p = 0.014), with dominant complex genotypes positively affecting endurance (p = 0.039). The presence of RX+II or XX+II was associated with a 1.763-fold higher likelihood of possessing a superior endurance capacity than that seen in healthy controls (90% CI = 1.037–3.089). Our findings propose an association of combined ACTN3 RX+XX and ACE II genotypes with enhanced endurance performance in elite Korean athletes. While causality remains to be confirmed, our study highlights the potential of ACTN3-ACE polymorphisms in predicting elite endurance. [ABSTRACT FROM AUTHOR]

Physical activity is recommended for the prevention of primary and secondary cardiovascular (CV) disease as it is linked to a number of health benefits, especially CV. However, recent research suggests that high-volume, long-term endurance exercise may hasten rather than slow the coronary atherosclerosis progression. This contentious theory has generated a great discussion and is still a major source of doubt when it comes to the clinical treatment of coronary artery disease (CAD) in athletes. CAD is the primary cause of sudden cardiac death in athletes over 35 years. Thus, recent studies evaluated the prevalence of CAD in athletes and its clinical and prognostic implications. Indeed, many studies have shown a relationship between endurance sports and higher volumes of coronary calcified plaque as determined by computed tomography. However, the precise pathogenetic substrate for the existence of an increased coronary calcification burden among endurance athletes remains unclear. Moreover, the idea that coronary plaques in elite athletes present a benign morphology has been cast into doubt by some recent studies showing potential association with adverse cardiovascular events. This review aims to analyze the association between physical activity and CAD, explaining possible underlying mechanisms of atherosclerotic progression and non-ischemic coronary lesions, focusing primarily on clinical and prognostic implications, multimodal evaluation, and management of CAD in endurance athletes. [ABSTRACT FROM AUTHOR]

Elite athletes in speed roller skates perceive skating to be a more demanding exercise for the groin when compared to other cyclic disciplines, increasing their risk of injury. The objective of this study was to monitor the kinematic and electromyographic parameters of roller speed skaters, linearly, on a treadmill, and to compare different skating speeds, one at 20 km/h and one at 32 km/h, at a 1° inclination. The acquisition was carried out by placing an inertial sensor at the level of the first sacral vertebra, and eight surface electromyographic probes on both lower limbs. The kinematic and electromyographic analysis on the treadmill showed that a higher speed requires more muscle activation, in terms of maximum and average values and co-activation, as it not only increases the intrinsic muscle demand in the district, but also the athlete's ability to coordinate the skating technique. The present study allows us to indicate not only how individual muscle districts are activated during skating on a surface different from the road, but also how different speeds affect the overall district load distributions concerning effective force, which is essential for the physiotherapist and kinesiologist for preventive and conditional purposes, while also considering possible variations in the skating technique in linear advancement. [ABSTRACT FROM AUTHOR]

The incorporation of triaxial accelerometers into Global Positioning Systems (GPS) has significantly advanced our understanding of accelerations in sports. However, inter-positional differences are unknown. This study aimed to explore the variability of acceleration and deceleration (Acc) distribution curves according to players' positions during soccer matches. Thirty-seven male players from a national-level Portuguese club were monitored using 10 Hz GPS with an embedded accelerometer during the 2021/2022 season. Resultant Acc was obtained from the x (lateral), y (frontal/back), and z (vertical) axes and expressed in gravitational units (g). Statistical Parametric Mapping was employed to compare playing positions: central defenders (CD), fullbacks (FB), central midfielders (CM), wide midfielders (WM), and strikers (ST). All positions exhibited a decreasing Acc distribution curve, very similar in shape, with a high frequency of events in the lower ranges (i.e., 0 to 1 g) and a lower frequency of events in the higher values (2 to 10 g). Post hoc comparisons revealed significant differences between all positions, except between FB and WM. Out of 1000 points in the curve, CD had 540, 535, 414, and 264 different points compared to FB, CM, WM, and ST, respectively. These findings indicate that players in different positions face distinct demands during matches, emphasizing the need for position-specific Acc analysis and training programming. By analyzing Acc as a continuous variable, this study highlights the importance of individualized monitoring to ensure the comprehensive and precise tracking of all player activities, without overlooking or omitting critical information. [ABSTRACT FROM AUTHOR]

Background: Basketball players rely on their lower limb strength for speed and agility. Therefore, it is important for strength and conditioning coaches to seek methods to assess and develop lower limb strength. Objectives: This study aimed to identify tests and variables used to assess lower body strength among elite basketball players and to provide normative values for the commonly used strength tests. Methods: A review of PubMed, MEDLINE, Scopus, and SPORTDiscus was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. The risk of bias was assessed using the Joanna Briggs Institute cross-sectional and cohort checklists. Results: Among the twelve reviewed studies, seven strength tests and five outcome variables were used. The most frequently used lower limb strength tests were the back squat (nine studies) and isometric mid-thigh pull (IMTP) (three studies), both reporting one repetition maximum (1RM) and peak force metrics. The most frequently used lower limb strength test was the back squat among males and IMTP among females. Conclusions: Among elite basketball players, the back squat 1RM is the most used lower limb strength test. However, across studies, a large variability was evidenced, which suggests that lower limb testing procedures are heterogeneous in this population. [ABSTRACT FROM AUTHOR]

The vitamin D receptor (VDR) is an important candidate gene in musculoskeletal phenotypes. Polymorphisms in the VDR have been previously associated with several pathologies and muscular strength in athletes and elderly people; however, the literature reported contradictory results. The object of this research was to verify the association between the most studied VDR variants (rs2228570, rs7975232, and rs1544410) and the increase in muscle mass in elite young soccer players. A sample of 55 soccer players (15–18 years old) from a professional team were selected for this study. DNA was extracted by the salting-out method, and polymorphisms were genotyped by PCR-RFLP, followed by 2% agarose gel electrophoresis. To test the effect of the three SNPs (single nucleotide polymorphisms), a logistic regression analysis was applied. The body composition determination was carried out through the skinfold thickness method, and the muscular area of the arm and lower limb were calculated using the Frisancho formula. All three polymorphisms met the Hardy–Weinberg equilibrium (p > 0.05) and their frequencies fell within the worldwide variability. A significant correlation between rs1544410 and the increase in calf muscle mass was observed. Individuals carrying the A allele showed higher calf muscular mass than those carrying the G allele (p = 0.034). Moreover, a haplotype analysis applied to the two SNPs in linkage disequilibrium (rs7975232 and rs1544410) showed that the AG haplotype appeared negatively correlated to the calf muscle area. In conclusion, we confirm an association between VDR polymorphisms and muscular mass that could encourage the genetic screening of the VDR gene to identify a potential risk of injury and for individual nutritional interventions. [ABSTRACT FROM AUTHOR]

While anaerobic fitness is highly important for the performance in Olympic (amateur) boxing, the relationship between anaerobic performance metrics is poorly understood, and profiling boxers according to their anaerobic capacity is still a challenge. With the current study in elite amateur boxers, we aimed to compare the metabolic and cardiovascular responses to different maximal tests and the intercorrelations between performance indices (peak and mean power, duration of the test, punching frequency) of several all-out tests and their correlation to physiological response metrics (blood lactate and heart rate, HR). Twelve male Olympic boxers performed a battery of tests, including 30 s Wingate cycling and arm cranking, boxing bag punching, steep uphill treadmill running to exhaustion, and progressive treadmill running VO2max test. Performance indices of different anaerobic tests were not closely correlated except for the duration of uphill running with body weight scaled (relative) peak and mean power produced during Wingate cycling test and absolute mean power of both Wingate tests. The number of punches landed on a bag per 30 s was associated only with relative power achieved during Wingate cycling test. HRpeak but not peak lactate response correlated strongly across exercise tasks. Finally, no correlation between the highly developed aerobic and anaerobic capacity, suggests a complex picture of the adaptation in elite amateur boxers. [ABSTRACT FROM AUTHOR]

Introduction: Football analysis is an applied research area that has seen a huge upsurge in recent years. More complex analysis to understand the soccer players' or teams' performances during matches is required. The objective of this study was to prove the usefulness of the expected goals on target (xGOT) metric, as a good indicator of a soccer team's performance in professional Spanish football leagues, both in the women's and men's categories. Method: The data for the Spanish teams were collected from the statistical website Football Reference. The 2023/24 season was analyzed for Spanish leagues, both in the women's and men's categories (LigaF and LaLiga, respectively). For all teams, the following variables were calculated: goals, possession value (PV), expected goals (xG) and xGOT. All data obtained for each variable were normalized by match (90 min). A descriptive and correlational statistical analysis was carried out. Results: In the men's league, this study found a high correlation between goals per match and xGOT (R2 = 0.9248) while in the women's league, there was a high correlation between goals per match (R2 = 0.9820) and xG and between goals per match and xGOT (R2 = 0.9574). Conclusions: In the LaLiga, the xGOT was the best metric that represented the match result while in the LigaF, the xG and the xGOT were the best metrics that represented the match score. [ABSTRACT FROM AUTHOR]

Balance is important in lifesaving competitions. We aimed to investigate the relationship between dynamic balance and physical characteristics and functions in elite lifesavers by measuring the foot muscle cross-sectional area, ankle joint muscle strength, toe grasp strength, plantar superficial sensation, and dynamic balance (Y-balance test). In this observational study, we measured the foot muscle cross-sectional area, ankle dorsiflexion, plantar flexion, external flexion, isometric muscle strength, toe grasp strength, and superficial foot sensation of 15 adult lifesavers (12 males). The results show that toe grasp strength and ankle plantar flexion isometric muscle strength are particularly important for the dynamic balance of elite lifesavers working on sandy surfaces. Sand training improves intrinsic muscle strength and dynamic balance function. However, high training intensity may reduce plantar surface sensation; this needs to be verified through sand training interventions in the future. [ABSTRACT FROM AUTHOR]

Determining the reference base of anthropometric parameters on a sample of elite athletes is one of the foundations of further research and forming a clearer picture of each sport and sports discipline. In this study, the aim was to describe the anthropometric and somatotype profiles of elite Finn class sailors and to determine the differences in the measured parameters between sailors at different levels of general competitive success. The subject sample included 57 Finn class sailors who competed at the open Finn European Championship. A set of 25 anthropometric variables were applied. The sailors were divided into three groups according to their level of general competitive success using World Sailing Rankings. Finn sailors had higher average values in almost all morphological characteristics when compared to the sailors in other Olympic classes. Considering the average values of somatotype categories, we determined that Finn sailors fit the endomorphic mesomorph somatotype category (3.94 ± 1.19 − 5.50 ± 1.19 − 1.63 ± 0.74). Significant differences were observed between more-successful, medium, and less-successful sailors in the variables of age, body mass, muscle mass, arm muscle mass, and endomorphy rating. These results indicate the possibility of selection processes and/or adaptation to sailing occurring in the Finn class. The anthropometric characteristics of Finn sailors compared to sailors in Olympic classes further "support" the Finn class being called the "heavy dinghy" male class. This study on anthropometric parameters, determined via a sample of top Finn sailors, may be of great help to coaches and young sailors when deciding on the selection of an adult sailing class. [ABSTRACT FROM AUTHOR]

Nutrition affects both body composition and, consequently, athletic performance. Only a few studies have assessed the nutritional behavior and knowledge of elite players. The present study aimed to assess the dietary intake, body composition, and nutritional knowledge of elite handball players. Thirty-nine handball players (age: 23.2 ± 2.7 years, weight: 88.2 ± 10.1 kg, height: 1.87 ± 0.07 m, and years of training: 13 ± 2) participated in the study. The athletes completed a set of anthropometric measurements, a 24 h food recall, and a translated edition of Abridged Nutrition for Sport Knowledge Questionnaire (A-NSKQ). The average body fat percentage was 16.7 ± 3.8%, while the average fat free mass was 73.9 ± 8.5 kg. The athletes' average daily energy intake was 2606.6 ± 756 kcal, while the average daily intake for carbohydrates, proteins, and fats was 243.85 ± 107.79 g [2.8 ± 1.3 g/kg BW/d—37.2 ± 10.5% of Total Energy Intake (TEI)], 131.59 ± 53.28 g (1.51 ± 0.7 g/kg BW/d—20.3 ± 6.9% of TEI), and 117.65 ± 40.52 g (40.9 ± 9.9% of TEI), respectively. For iron, calcium, and vitamin D, the average daily intakes were 19.33 ± 10.22 mg, 1287.7 ± 676.42 mg, and 3.22 ± 3.57 mcg respectively. The average success rate on the A-NSKQ was only 38.5 ± 10.7% out of 100. Elite handball players exhibit inadequate dietary intake and sports nutrition knowledge. Nutritional education should be a primary concern towards the amelioration of their athletic performance. [ABSTRACT FROM AUTHOR]

Women's wrestling is actively practiced in many countries. While severe spinal injuries pose a threat to an athlete's career and health, research on severe spinal injuries in female wrestlers remains limited. The aim of this study was to investigate the characteristics of severe spinal injuries and post-injury management in Korean female wrestlers. We enrolled 54 female wrestlers participating in the national team selection competition. Interviews were conducted to examine the characteristics of spinal injuries that resulted in a time loss of more than three weeks from training throughout their athletic careers and their post-injury management practices. Approximately 46% of participants experienced severe spinal injuries, and 52% faced re-injuries during their wrestling careers. These injuries predominantly occurred during technical training due to overuse during tackling and standing attacks. The most frequent injuries were lumbosacral disc injuries (72%) and cervical disc injuries (20%), with 36% requiring surgery. Nearly half of the injured athletes received specialized rehabilitation, yet roughly 76% resumed training without medical clearance. Athletes injured during their student years were notably less likely to receive specialized rehabilitation compared with those injured during their professional careers (p = 0.011). On average, athletes returned to play within 2.7 to 3.0 months. Spinal injury characteristics and post-injury management were not significantly different between the light- and heavyweight classes. While Korean female wrestlers are at a high risk of experiencing severe spinal injuries and re-injuries during their careers, appropriate post-injury management is often lacking, highlighting the need for proactive intervention by healthcare professionals to prevent recurrent spinal injuries in female wrestlers and to ensure safe return to training. [ABSTRACT FROM AUTHOR]

This study aimed to examine the effects of black maca supplementation on isokinetic muscle function and inflammatory markers in athletes and to extend these findings to non-athletes. The study involved 24 male participants, including 16 elite athletes (soft tennis and table tennis players) and 8 non-athletes (university students). Participants consumed capsules containing 2.5 g of 100% concentrated black maca extract over a 12-week period. Isokinetic muscle performance and physical fitness (strength, muscular endurance, flexibility, power, agility, cardiovascular endurance) assessments were conducted at baseline and after 12 weeks of supplementation. Two-way within-factor ANOVA showed a significant group × time interaction for 120°/s flexor movements (p < 0.05). Paired t-tests demonstrated significant improvements in 30°/s and 120°/s extensor and flexor movements in both athlete groups (p < 0.05, p < 0.01). Similarly, significant enhancements were observed in the non-athletes for the 30°/s flexor and 120°/s extensor and flexor movements (p < 0.01). Furthermore, reductions in interleukin-6 (from 137.9 ± 8.8 to 132.7 ± 4.6, p < 0.05) and tumor necrosis factor-alpha (from 274.1 ± 13.4 to 264.2 ± 3.2, p < 0.05) were noted in the soft tennis group. The table tennis group also showed significant decreases in interleukin-6 (from 135.9 ± 4.7 to 131.3 ± 2.5, p < 0.01) and tumor necrosis factor-alpha (from 282.1 ± 19.2 to 267.0 ± 6.4, p < 0.05). No significant changes were observed in the non-athlete group. Black maca supplementation may enhance isokinetic muscle function in elite athletes by reducing muscle contraction fatigue and improving anti-inflammatory responses. [ABSTRACT FROM AUTHOR]

The interest in using new technologies to obtain recordings of on-water kinetic variables for assessing the performance of elite sprint kayakers has increased over the last decades but systematic approaches are warranted to ensure the validity and reliability of these measures. This study has an innovative approach, and the aim was to develop a new versatile jig including reference force sensors for both the calibration and validation of mutual static and dynamic stroke forces as measured with instrumented paddles at the high force levels used in elite sprint kayaking. Methods: A jig was constructed using a modified gym weight stack and a frame consisting of aluminum profiles permitting a fastening of custom-made kayak paddle shaft and blade support devices with certified force transducers combined with a data acquisition system to record blade and hand forces during static (constant load) and dynamic conditions (by paddle stroke simulation). A linear motion path incorporating a ball-bearing equipped carriage with sensors for the measurement of vertical distance and horizontal displacement was attached to the frame for recordings of various position measures on the paddle. The jig design with all components is extensively described to permit replication. The procedures for assessing the accuracy of the jig force instrumentation are reported, and with one brand of instrumented paddle used as an example, methods are described for force calibration and validation during static and dynamic conditions. Results: The results illustrate that the measured force with the jig instrumentation was similar to the applied force, calculated from the applied accurate mass (within a −1.4 to 1.8% difference) and similar to the force as calculated from the applied mass with the weight stack (within a −0.57 to 1.16% difference). The jig was suitable for the calibration and validation of forces in a range relevant for elite sprint kayaking under both static and dynamic conditions. During static conditions with a force direction equal to the calibration conditions and a force range from 98 to 590 N, all values for the instrumented paddle were within a −3.4 to 3.0% difference from the jig sensor values and 28 of 36 values were within ±2%. During dynamic conditions with paddle stroke simulations at 60 and 100 strokes/min and a target peak force of 400 N, the common force variables as measured by the instrumented paddle were not significantly different from the same measures by the jig (values at 100 strokes/min: peak force; 406.9 ± 18.4 vs. 401.9 ± 17.2 N, mean force; 212.8 ± 15.4 vs. 212.0 ± 14.4 N, time to peak force; 0.17 ± 0.02 vs. 0.18 ± 0.02 s, force impulse; 90.8 ± 11.2 vs. 90.5 ± 10.8 Ns, impulse duration; 0.43 ± 0.03 vs. 0.43 ± 0.03 s). Conclusion: A novel jig with several new functions is presented that enables the calibration and validation of force measurements with instrumented paddles by providing standardized conditions for calibration and force validation during both static and dynamic conditions in a force range relevant to elite sprint kayaking. [ABSTRACT FROM AUTHOR]

The effects of face immersion and concurrent exercise on the diving reflex evoked by breath-hold (BH) differ, yet little is known about the combined effects of different BH conditions on aerobic fitness in elite athletes. This study aimed to assess the acute effects of various BH conditions on 18 male elite rugby players (age: 23.5 ± 1.8 years; height: 183.3 ± 3.4 cm; body mass: 84.8 ± 8.5 kg) and identify the BH condition eliciting the greatest aerobic fitness activation. Participants underwent five warm-up conditions: baseline regular breathing, dynamic dry BH (DD), static dry BH (SD), wet dynamic BH (WD), and wet static BH (WS). Significant differences (p < 0.05) were found in red blood cells (RBCs), red blood cell volume (RGB), and hematocrit (HCT) pre- and post-warm-up. Peak oxygen uptake (VO2peak) and relative oxygen uptake (VO2/kgpeak) varied significantly across conditions, with BH groups showing notably higher values than the regular breathing group (p < 0.05). Interaction effects of facial immersion and movement conditions were significant for VO2peak, VO2/kgpeak, and the cardiopulmonary optimal point (p < 0.05). Specifically, VO2peak and peak stroke volume (SVpeak) were significantly higher in the DD group compared to that in other conditions. Increases in VO2peak were strongly correlated with changes in RBCs and HCT induced by DD warm-up (r∆RBC = 0.84, r∆HCT = 0.77, p < 0.01). In conclusion, DD BH warm-up appears to optimize subsequent aerobic performance in elite athletes. [ABSTRACT FROM AUTHOR]

Maximal oxygen uptake (VO2max) is a determining indicator for cardiorespiratory capacity in endurance athletes, and epigenetics is crucial in its levels and variability. This initial study examined a broad plasma miRNA profile of twenty-three trained elite endurance athletes with similar training volumes but different VO2max in response to an acute maximal graded endurance test. Six were clustered as higher/lower levels based on their VO2max (75.4 ± 0.9 and 60.1 ± 5.0 mL.kg−1.min−1). Plasma was obtained from athletes before and after the test and 15 ng of total RNA was extracted and detected using an SYBR-based 1113 miRNA RT-qPCR panel. A total of 51 miRNAs were differentially expressed among group comparisons. Relative amounts of miRNA showed a clustering behavior among groups regarding distinct performance/time points. Significantly expressed miRNAs were used to perform functional bioinformatic analysis (DIANA tools). Fatty acid metabolism pathways were strongly targeted for the significantly different miRNAs in all performance groups and time points (p < 0.001). Although this pathway does not solely determine endurance performance, their significant contribution is certainly achieved through the involvement of miRNAs. A highly genetically dependent gold standard variable for performance evaluation in a homogeneous group of elite athletes allowed genetic/epigenetic aspects related to fatty acid pathways to emerge. [ABSTRACT FROM AUTHOR]

This investigation aimed to explore the relationship between Chinese elite wrestlers and the polymorphic loci of explosive strength genes, and to further explore the feasibility of its application to athlete selection. The snapshot technique was used to resolve the polymorphic loci of explosive power genes in the wrestler group (59 elite wrestlers) and the control group (180 ordinary college students), and to analyze the genotype frequencies and allele frequencies of each group. A chi-square test was performed on the genotype and allele distribution data of each group to analyze the loci of explosive power genes that were associated with elite wrestlers. The loci that had an association with elite wrestlers were combined with the genotyping data, and the dominance ratios of the genotypes were calculated using the chi-square test to determine the dominant genotypes associated with elite wrestlers. The VDR gene rs2228570 locus exhibited statistically significant differences in genotype and allele distributions between elite wrestlers and the general population (p < 0.01). At the rs2228570 locus of the VDR gene, the difference between the CC genotype and other genotypes was statistically significant (p < 0.05). The rs2228570 locus of the VDR gene was identified as the locus associated with Chinese elite wrestlers. The polymorphism of the VDR gene can be used as a biomarker for Chinese wrestlers, and the CC genotype can be used as a molecular marker for the selection of Chinese elite athletes in this sport. However, expanding the sample size of elite athletes is necessary to further validate the scientific validity and feasibility of these findings. [ABSTRACT FROM AUTHOR]

This study proposes to monitor the physical, immune and cognitive responses and adaptations of elite rugby players throughout the season based on the loads performed. Anthropometric measurements, physical fitness tests (e.g., muscle strength and power, linear and change-of-direction speed, cardiorespiratory fitness) and analyses of serum concentrations of markers of muscle damage (creatine kinase [CK] and lactate dehydrogenase [LDH]) and brain-derived neurotrophic factor (BDNF) were carried out over a sporting season (24 weeks) for 17 elite rugby players (10 forwards and 7 backs) aged 18.91 ± 0.76 years. The physical fitness test results show improvements in the performance of both forwards and backs over the season (p < 0.05), with an advantage for backs compared with forwards in most tests (p < 0.05). Muscle damage markers decreased at the end of the season compared with the baseline levels for forwards (p < 0.05). CK levels were unchanged for the backs, but there were increased LDH concentrations at the end of the season compared with baseline (p < 0.05). Serum BDNF levels decreased for the total group between the second and third sampling (p < 0.05). The muscular and physical capacities of rugby players differ according to their playing position. Immune responses and adaptations, as well as BDNF levels, vary throughout the season and depend on the physical load performed. [ABSTRACT FROM AUTHOR]

Most studies on sprint performance have focused on kinematics and kinetics of the musculoskeletal system for adults, with little research on the central sensorimotor transmission and processes, especially for adolescent sprinters. This study aimed to determine whether differences in the integrity of the central auditory system and audiomotor transmissions between the elite and sub-elite adolescent sprinters may affect their performance in the 100 m time. Twenty-nine adolescent junior high school students, including elite national-class and sub-elite regional-class athletes, were assessed. Visual and auditory evoked potentials (VEP and AEP) as well as electroencephalography (EEG) and electromyography (EMG) were recorded and analyzed during a sprint start. The electrophysiological results clearly reveal differences in central auditory transmission between elite and sub-elite groups, and between sexes. There were significant differences between elite and sub-elite groups, and during a sprint start, the EEG activities for elite female and male athletes showed significant time-dependent differences in peak amplitudes following the three auditory cues (ready, set, and gunshot). These findings can provide coaches with a more comprehensive consideration for sports-specific selection based on the athletes' individual conditions, e.g., sensorimotor neuroplastic training for providing precise and efficient training methods to improve young sprinters' performance. [ABSTRACT FROM AUTHOR]

Advanced footwear technology featuring stack heights higher than 30 mm has been proven to improve running economy in elite and recreational runners. While it is understood that the physiological benefit is highly individual, the individual biomechanical response to different stack heights remains unclear. Thirty-one runners performed running trials with three different shoe conditions of 25 mm, 35 mm, and 45 mm stack height on an outdoor running course wearing a STRYD sensor. The STRYD running variables for each participant were normalized to the 25 mm shoe condition and used to cluster participants into three distinct groups. Each cluster showed unique running patterns, with leg spring stiffness and vertical oscillation contributing most to the variance. No significant differences were found between clusters in terms of body height, body weight, leg length, and running speed. This study indicates that runners change running patterns individually when running with footwear featuring different stack heights. Clustering these patterns can help understand subgroups of runners and potentially support running shoe recommendations. [ABSTRACT FROM AUTHOR]

The purpose of this study was to (a) correlate the weekly external training load with the game running performance in season microcycles and (b) specify the optimal training/game ratio of the weekly external load in elite youth soccer players. The total distance (TD), the high-speed running distance (HSRD) (19.8–25.2 km/h), the ZONE6 distance (>25.2 km/h), the acceleration (ACC) (≥+2 m/s2), and the deceleration (DEC) (≥−2 m/s2) were monitored with global positioning system (GPS) technology throughout 18 microcycles and official games. TD had a very high positive correlation average (r = 0.820, p = 0.001), the HSRD had a high positive correlation average (r = 0.658, p = 0.001), the ZONE6 distance and DEC had a moderate positive correlation average ((r = 0.473, p = 0.001) and (r = 0.478, p = 0.001), respectively), and the ACC had a low positive correlation average (r = 0.364, p = 0.001) between microcycles and games. Regarding the training/game ratio, the HSRD showed statistically significant differences between ratios 1.43 and 2.60 (p = 0.012, p ≤ 0.05), the ACC between ratios 2.42 and 4.45 (p = 0.050, p ≤ 0.05) and ratios 3.29 and 4.45 (p = 0.046, p ≤ 0.05), and the DEC between ratios 2.28 and 3.94 (p = 0.034, p ≤ 0.05). Considering the correlation between weekly training and game external load, high weekly training TD values correspond to higher game values, whereas HSRD, ZONE6 distance, ACC, and DEC, which determine training intensity, should be trained in a specific volume. Training/game ratios of 1.43, 2.42 to 3.29, and 2.28 to 3.11 seem to be optimal for HSRD, ACC, and DEC weekly training, respectively. [ABSTRACT FROM AUTHOR]

Background/Objectives: Several systematic reviews and meta-analyses have been conducted to date indicating a high prevalence of disordered eating in elite athletes and associated risk factors. However, the substantial time burden associated with locating and comparing these reviews, which are varied in methodology and sampling focus, may be a barrier for informing policy and best practice as well as directing future research. This umbrella review aimed to provide a summary of evidence across published reviews regarding the prevalence and risk factors for disordered eating (including body image concerns and eating disorders) in elite athletes. Methods: Five databases (CINAHL, PsycINFO, MEDLINE, Scopus, and SPORTDiscus) were systematically searched for peer-reviewed systematic reviews and meta-analyses that met the following inclusion criteria: (1) investigated prevalence and risk factors for disordered eating, (2) included a sample of elite athletes, and (3) available in English. The included studies underwent data extraction and risk of bias assessment using the AMSTAR 2. Results: The initial search identified 1828 articles that were screened for title and abstract and then full text, leaving 24 systematic reviews (including 10 meta-analyses). Disordered eating was prevalent across elite athletes, including males and females and across sport type. Elite athletes were at elevated risk for disordered eating and eating disorders but at lower risk for body image concerns versus non-athlete controls. Several risk factors were identified, including female gender, competing in lean sports, and experiencing career changes. Few reviews or meta-analyses examined perceived pressures within the sporting environment, and most had substantial risk of bias concerns. Conclusions: Elite athletes are at risk for the spectrum of disordered eating, and all should be considered for primary prevention and screening. Further research is needed regarding sport-specific versus general pressures and mediators of risk to better inform interventions. [ABSTRACT FROM AUTHOR]

Recently, there has been a growing interest in relation to the female athlete, especially in widespread disciplines such as football. Concerns about vitamin D deficiency status have recently been considered due to its effects on the performance and health status of female footballers. However, its relationship to body composition and muscle damage in female football athletes remains unclear to date. The purpose of the present study was to analyse the association of the vitamin D status of Spanish elite female football players with anthropometric variables and markers of muscle damage. Ethical consent was obtained from a total of 21 players from a Spanish elite women's football team (20–33 years). Anthropometric analysis was carried out according to the standardised protocol of the International Society for the Advancement of Kineanthropometry (ISAK). The clinical analyses, based on urine and blood samples, were carried out by the club's medical staff at the start of the season in the early morning in a fasting state. The athletes were also asked about the regularity of their menstrual cycle and some dietary habits. Thirty-three percent of the female athletes had vitamin D levels below the reference values. Significantly higher FM values were observed in athletes with low vitamin D status (p < 0.05), as well as statistically significant negative correlations between vitamin D levels and FM (p < 0.05) in the group of female players with vitamin D levels below the baseline values. No significant associations were observed between markers of muscle damage and the other variables. Complementing an assessment of body composition with a biochemical analysis of vitamin D levels may be an interesting strategy in the process of monitoring the elite female football player throughout the season. [ABSTRACT FROM AUTHOR]

In the long-term performance development of rhythmic gymnasts aged 16–17, athletes enter a high-performance training phase, marked by increased training loads and preparation for international competitions. This study aimed to (1) provide an overview of methods used to capture external and internal training/competition loads in elite rhythmic gymnasts, and (2) identify measurements of external and internal training/competition loads and their responses during monitored periods. Conducted according to PRISMA guidelines, the systematic review included 6 studies out of the 815 initially identified. The most common methods for calculating external training load were hours or minutes per week. Internal measures varied and included objective methods such as heart rate monitoring and biochemical, hormonal, and hematological assessments from saliva and blood samples. Among subjective methods, session-RPE was most frequently used, along with other questionnaires examining recovery, well-being, sleep, and competition anxiety. The analyzed studies integrated diverse external and internal training load variables, delving into their impact on athlete's biochemical parameters, recovery, and well-being. Pre-competitive and competitive training periods were the focal points of measuring loads. The complex training structure of rhythmic gymnastics can complicate the calculation of training loads. Therefore, more studies are needed to explore the dose-response relationships between training load and training adaptations, fatigue, and recovery. [ABSTRACT FROM AUTHOR]

This study aimed to measure the differences in commonly used summary acceleration metrics during elite Australian football games under three different data processing protocols (raw, custom-processed, manufacturer-processed). Estimates of distance, speed and acceleration were collected with a 10-Hz GNSS tracking technology device from fourteen matches of 38 elite Australian football players from one team. Raw and manufacturer-processed data were exported from respective proprietary software and two common summary acceleration metrics (number of efforts and distance within medium/high-intensity zone) were calculated for the three processing methods. To estimate the effect of the three different data processing methods on the summary metrics, linear mixed models were used. The main findings demonstrated that there were substantial differences between the three processing methods; the manufacturer-processed acceleration data had the lowest reported distance (up to 184 times lower) and efforts (up to 89 times lower), followed by the custom-processed distance (up to 3.3 times lower) and efforts (up to 4.3 times lower), where raw data had the highest reported distance and efforts. The results indicated that different processing methods changed the metric output and in turn alters the quantification of the demands of a sport (volume, intensity and frequency of the metrics). Coaches, practitioners and researchers need to understand that various processing methods alter the summary metrics of acceleration data. By being informed about how these metrics are affected by processing methods, they can better interpret the data available and effectively tailor their training programs to match the demands of competition. [ABSTRACT FROM AUTHOR]

Consideration of workload intensity and peak demands across different periods of basketball games contributes to understanding the external physical requirements of elite basketball players. Therefore, the aim of this study was to investigate the average intensity and peak demands encountered by players throughout game quarters. PlayerLoad per minute and PlayerLoad at three different time samples (30 s, 1 min, and 3 min) were used as workload metrics. A total of 14 professional elite male basketball players were monitored during 30 official games to investigate this. A linear mixed model and Cohen's d were employed to identify significant differences and quantify the effect sizes among game quarters. The results showed a significant, moderate effect in PlayerLoad per minute between Q1 vs. Q4, and a small effect between Q2 and Q3 vs. Q4. Furthermore, a small to moderate decline was observed in external peak values for PlayerLoad across game quarters. Specifically,, a significant decrease was found for the 3 min time window between Q1 and other quarters. The findings from the present study suggest that professional basketball players tend to experience fatigue or reduced physical output as the game progresses. [ABSTRACT FROM AUTHOR]

This study investigates gender differences in core muscle morphology among elite alpine skiers using ultrasonography, highlighting significant disparities that could influence training and injury prevention strategies. Methods: A cross-sectional design was employed, examining ultrasound imaging (USI) in 22 elite skiers (11 male, 11 female) to assess the thickness of the external oblique (EO), internal oblique (IO), transversus abdominis (TrAb), and rectus abdominis (RA) muscles. Results: Significant differences were noted, with male skiers displaying greater muscle thickness, particularly in the right IO and RA and left IO, EO, TrAb, and RA. Conclusions: These findings suggest that male and female skiers may require different training approaches to optimize performance and reduce injury risks. This research contributes to a deeper understanding of the physical demands on elite skiers and underscores the need for gender-specific training regimens to enhance athletic outcomes and prevent injuries. [ABSTRACT FROM AUTHOR]

This study sought to assess how post-game creatine kinase (CK) levels correlate with the number of sprints and the impact of the ACTN3 polymorphism on this response. This research constituted a descriptive/observational, retrospective cross-sectional study. DNA was extracted from blood samples for ACTN3 polymorphism genotyping. CK was measured 48 h after official matches, and the number of sprints (>19 km/h) was tracked using Global Positioning System (GPS) technology. The main cohort included 23 professional soccer players from the top tier of the Brazilian Championship. We analyzed 115 GPS + CK data sets. The replication cohort comprised 18 professional soccer players from the First Division of the Championship, had the same methodology applied, and featured a total of 90 GPS (sprints > 25.2 km/h) + CK data sets. For the main cohort, a significant positive correlation was seen between the number of sprints and the CK levels (p = 0.009). Athletes with the ACTN3 RR genotype had higher CK levels as more sprints were performed during the match (p = 0.017). However, the relationship was not found for X allele carriers (p > 0.05). For the replication cohort, there was a near-significant correlation between CK levels and the number of sprints (p = 0.05), and RR individuals showed a significant association (p = 0.01), whereas X allele carriers did not (p = 0.06). A greater number of sprints during matches is linked to higher CK levels, primarily among players with the ACTN3 RR genotype, which is potentially due to an increased presence of type II muscle fibers. These findings were replicated for both cohorts of elite Brazilian soccer players, emphasizing the importance of genetic factors in injury prevention. [ABSTRACT FROM AUTHOR]

Athletes' anthropometry, and especially their body composition, plays an important role in sport performance in general and in Trainera rowing in particular. Rowers' anthropometric and performance profiles may vary according to their position in the boat. The objectives of this study were to investigate the relationship between anthropometry, physical performance, physiological variables, and elite male rowers' boat positions. Twenty elite male traditional rowers were assessed and categorized according to their boat position: either in the middle of the boat (M) (n = 9) or in the bow and stern positions (BS) (n = 11). Anthropometric measurements and body composition were obtained for each rower, and physical performance was measured by a 45-s supramaximal rowing test and a VO2max incremental test on a Concept II rowing ergometer. The results showed that the rowers in the middle were taller (186.6 ± 4.9 cm), and significant differences were also found between the two groups according to body mass (BS 72.3 ± 3.8 vs. M 85.4 ± 4.3) and peak power (BS 641.5 ± 84 vs. M 737 ± 47.1), mean power (BS 538.5 ± 48.4 vs. M 604.1 ± 42.3), and physiological parameters (p < 0.05), VO2max (BS 66.5 ± 4.9 vs. M 59.3 ± 6.7). It can be concluded that height could be associated with elite rowers' performance and that a lower body mass index is related to better performance in bow and stern positions. [ABSTRACT FROM AUTHOR]

Those responsible for elite and youth athletes are increasingly aware of the need to balance the quest for superior performance with the need to protect the physical and psychological wellbeing of athletes. As a result, regular assessment of risks to mental health is a common feature in sports organisations. In the present study, the Brazil Mood Scale (BRAMS) was administered to 898 athletes (387 female, 511 male, age range: 12–44 years) at a leading sports club in Rio de Janeiro using either "past week" or "right now" response timeframes. Using seeded k-means cluster analysis, six distinct mood profile clusters were identified, referred to as the iceberg, surface, submerged, shark fin, inverse iceberg, and inverse Everest profiles. The latter three profiles, which are associated with varying degrees of increased risk to mental health, were reported by 238 athletes (26.5%). The prevalence of these three mood clusters varied according to the response timeframe (past week > right now) and the sex of the athletes (female > male). The prevalence of the iceberg profile varied by athlete sex (male > female), and age (12–17 years > 18+ years). Findings supported use of the BRAMS as a screening tool for the risk of psychological issues among athletes in Brazilian sports organisations. [ABSTRACT FROM AUTHOR]

Ischemic preconditioning (IPC), which involves episodes of blood flow restriction followed by reperfusion, has uncertain effects on athletes. Additionally, employing sports-specific tests that are highly familiar to athletes can enhance methodological rigor in determining IPC's effects on taekwondo performance. This study aimed to investigate IPC's influence on taekwondo athletes' performance through two studies. To induce occlusion in both studies, the cuff was inflated to an individualized occlusion pressure established for each athlete's lower limb, with four cycles of occlusion lasting five minutes each, alternated with five-minute reperfusion intervals. Both traditional frequentist statistics and Bayesian analysis were employed. In the first study, eleven high-level athletes were subjected to either IPC or a placebo (SHAM) procedure on both legs, followed by performing countermovement jumps (CMJs) and a specific taekwondo endurance test. However, no significant differences were observed in taekwondo endurance performance or CMJ between the IPC and SHAM conditions. The second study involved fourteen elite athletes who underwent the same IPC or SHAM conditions, performing CMJ and three bouts of the Multiple Frequency Speed of Kick test (FSKTmult) in three blocks, each separated by approximately thirty minutes. Again, the results indicated no significant differences in FSKTmult measures or CMJ performance between the two conditions. In conclusion, IPC did not significantly affect neuromuscular (in both studies), endurance (in the first study), or anaerobic (in the second study) performance in these taekwondo athletes. [ABSTRACT FROM AUTHOR]

Background: Previous studies demonstrated that variations of fT3, even within the euthyroid range, can influence cardiac function. Our aim was to investigate whether thyroid hormones, even within the euthyroid range, are associated with the magnitude of exercise-induced cardiac remodeling in Olympic athletes. Methods: We evaluated 1342 Olympic athletes (mean age 25.6 ± 5.1) practicing different sporting disciplines (power, skills, endurance, and mixed). Athletes underwent blood testing (thyroid stimulating hormone, fT3, and fT4), echocardiography, and exercise-stress testing. Athletes taking thyroid hormones, affected by thyroiditis, or presenting TSH out of ranges were excluded. Results: The level of thyroid hormones varied according to the type of sporting discipline practiced: endurance athletes presented the lowest TSH (p < 0.0001), fT3 (p = 0.007), and fT4 (p < 0.0001) in comparison to the remaining ones. Resting heart rate (HR) was positively correlated to fT3 in athletes of different disciplines (power: p = 0.0002, R2 = 0.04; skill: p = 0.0009, R2 = 0.05; endurance: p = 0.007, R2 = 0.03; and mixed: p = 0.04, R2 = 0.01). The same results were seen for peak HR in the exercise-stress test in athletes engaged in power, skill, and endurance (respectively, p < 0.0001, R2 = 0.04; p = 0.01, R2 = 0.04; and p = 0.005, R2 = 0.02). Moreover, a positive correlation was observed with cardiac dimensions, i.e., interventricular septum (power: p < 0.0001, R2 = 0.11; skill: p = 0.02, R2 = 0.03; endurance: p = 0.002, R2 = 0.03; mixed: p < 0.0001, R2 = 0.04). Furthermore, fT3 was directly correlated with the left ventricle (LV) end-diastolic volume in skills (p = 0.04, R2 = 0.03), endurance (p = 0.04, R2 = 0.01), and mixed (p = 0.04, R2 = 0.01). Conclusions: Thyroid hormones, even within the euthyroid range, are associated with cardiac adaptive response to exercise and may contribute to exercise-induced cardiac remodeling. [ABSTRACT FROM AUTHOR]

This study explored the impact of short rest intervals on resisted sprint training in elite youth soccer players, specifically targeting enhanced initial-phase explosive acceleration without altering sprint mechanics. Fifteen U19 soccer players participated in a randomized crossover design trial, executing two sprint conditions: RST2M (6 sprints of 20 m resisted sprints with 2 min rest intervals) and RST40S (6 sprints of 20 m resisted sprints with 40 s rest intervals), both under a load equivalent to 30% of sprint velocity decrement using a resistance device. To gauge neuromuscular fatigue, countermovement jumps were performed before and after each session, and the fatigue index along with sprint decrement percentage were calculated. Interestingly, the results indicated no significant differences in sprint performance or mechanical variables between RST2M and RST40S, suggesting that the duration of rest intervals did not affect the outcomes. Horizontal resistance appeared to mitigate compensatory patterns typically induced by fatigue in short rest periods, maintaining effective joint movement and hip extensor recruitment necessary for producing horizontal ground forces. These findings propose a novel training strategy that could simultaneously enhance sprint mechanics during initial accelerations and repeated sprint abilities for elite youth soccer players—a methodology not previously employed [ABSTRACT FROM AUTHOR]