Jose Antonio Asian-Clemente, Bernardo Requena, Jose Vicente Beltran-Garrido, Piotr Żmijewski
{"title":"The Impact of Field Size on Positional and Possession Games: Variations in Physical Demands across Player Positions in Soccer Training.","authors":"Jose Antonio Asian-Clemente, Bernardo Requena, Jose Vicente Beltran-Garrido, Piotr Żmijewski","doi":"10.5114/jhk/222302","DOIUrl":"10.5114/jhk/222302","url":null,"abstract":"<p><p>This study investigated how pitch size and a task type (position vs. possession games) influence running demands and external load across player positions in soccer training. Twenty-five young professional soccer players (21.9 ± 1.9 years) participated in 36 training sessions during the 2021-2022 season. Position and possession games were conducted on three pitch sizes (small, medium, large). Players wore GPS devices to measure total distance covered (DC), peak speed, and acceleration/deceleration metrics (low-intensity < ±3 m•s⁻<sup>2</sup> and high-intensity > ±3 m•s⁻<sup>2</sup>). Mixed models assessed the effects of pitch size and a task type on these metrics and positional differences. Possession games elicited higher total DC than position games across all sizes studied (p < 0.005). In the large format, the peak speed was higher in possession than in position games (p < 0.001). On small pitches, possession games resulted in greater low-intensity accelerations/decelerations (ACC<sub><3</sub>/DEC<sub><3</sub>), but fewer high-intensity accelerations/decelerations (ACC<sub>>3</sub>/DEC<sub>>3</sub>) and maximal deceleration compared to position games (p < 0.05). Positional analysis revealed that central defenders and fullbacks reached greater total DC across all three formats of possession games (p < 0.05). Central-midfielders and forwards recorded higher peak speeds in the large possession game (p ≤ 0.01). Wide-midfielders achieved fewer ACC<sub><3</sub> and DEC<sub><3</sub> events in position games during the small format, while fullbacks performed fewer ACC<sub><3</sub> but more ACC<sub>>3</sub> in the same format during position games (p ≤ 0.05). Field size and the game format significantly affect external load in soccer. Possession games require greater total DC regardless of size and higher peak speeds on larger fields, while position games involve more high-intensity actions, reflecting players' tactical roles.</p>","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"103 ","pages":"261-275"},"PeriodicalIF":4.0,"publicationDate":"2026-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13551327/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148912453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Inter-Limb Asymmetry: Lessons Learnt from 10 Years of Data Collection in Performance Sport.","authors":"Chris Bishop, Jose Afonso, Anthony Turner","doi":"10.5114/jhk/224732","DOIUrl":"10.5114/jhk/224732","url":null,"abstract":"<p><p>For years, inter-limb asymmetry data have been reported in performance science and injury rehabilitation literature, together with routine monitoring in professional practice. Intuitively, many practitioners are almost 'hard-wired' to think that if a sizable inter-limb asymmetry presents itself, then something must be done to correct it. However, before any attempt is considered regarding trying to alter the magnitude of asymmetry, practitioners and researchers should first better comprehend the associated challenges and pitfalls of inter-limb asymmetry data. Once these are understood, a series of robust and pragmatic principles are proposed to enhance the utility of asymmetry data, which in turn, should help ensure that appropriate due-diligence is undertaken, serving to guide subsequent decision-making when considering this metric.</p>","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"103 ","pages":"5-14"},"PeriodicalIF":4.0,"publicationDate":"2026-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13551325/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148912353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andrés López-Sagarra, Manuel A Rodríguez-Pérez, Alexis Padrón-Cabo, Andrés Baena-Raya
{"title":"The Acceleration-Speed Profile in Professional Soccer Players: A Comparative Study According to Sex, the Sports Level and the Playing Position.","authors":"Andrés López-Sagarra, Manuel A Rodríguez-Pérez, Alexis Padrón-Cabo, Andrés Baena-Raya","doi":"10.5114/jhk/220252","DOIUrl":"10.5114/jhk/220252","url":null,"abstract":"<p><p>This study aimed to compare maximum acceleration and speed capabilities in professional soccer players, both derived from the acceleration-speed (AS) profile (theoretical maximum acceleration [A<sub>0</sub>] and speed [S<sub>0</sub>]) and direct assessment (maximum acceleration [Max<sub>Acc</sub>] and speed [Max<sub>Speed</sub>]), according to both (i) sex and the sports level, and (ii) the playing position. A total of 737 professional women and men soccer players were monitored during 5-10 official matches. Data were collected using 18-Hz GPS devices to derive AS profiles and directly measure acceleration and speed output. Across all playing levels, professional men soccer players demonstrated significantly (p < 0.01) higher values than female players for A<sub>0</sub> (d = 1.14-1.87), S<sub>0</sub> (d = 3.88-4.82), Max<sub>Acc</sub> (d = 0.57-1.22), and Max<sub>Speed</sub> (d = 2.46-2.81). Likewise, players of higher sports levels showed superior output than their lower counterparts (First Men's Division > Second Men's Division > Under 20 Men's Division; p < 0.05). Position-specific analysis revealed that midfielders had significantly (p < 0.05) lower Max<sub>Speed</sub> values than other positions such as full-backs (d = 0.63-1.17), wide midfielders (d = 0.82), and forwards (d = 0.67-1.06) in both the First and Second Divisions. Conversely, wide midfielders in the Under 20 Men's Division exhibited significantly (p < 0.05) higher A<sub>0</sub> values than central defenders (d = 0.78). These findings highlight the importance of conducting sex- and position-specific analyses of the AS profile to effectively monitor acceleration and speed capacities across different sports levels in professional soccer.</p>","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"103 ","pages":"149-160"},"PeriodicalIF":4.0,"publicationDate":"2026-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13551336/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148912361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Level of Effort: A Practical Approach for Resistance Training Monitoring and Prescription.","authors":"Fernando Pareja-Blanco, Irineu Loturco","doi":"10.5114/jhk/221229","DOIUrl":"10.5114/jhk/221229","url":null,"abstract":"<p><p>Accurate prescription and monitoring of resistance training (RT) load require ensuring that the external load prescribed by the coach reflects the internal demands experienced by the athlete. Although repetitions in reserve (RIR) have been proposed as a practical method for quantifying proximity to failure, their use in isolation assumes that identical RIR values correspond to equivalent physiological stimuli across different repetition ranges and intensities. This assumption does not necessarily reflect comparable internal loading conditions. To address this limitation, the concept of \"level of effort\"-defined as the \"relationship between the repetitions performed and the maximum number of repetitions that could be completed with a given load\"-offers a proportion-based and more comprehensive representation of exertion. When quantified through movement velocity, the level of effort integrates two critical variables: relative intensity (via the fastest repetition velocity) and fatigue development (via velocity loss), allowing accurate estimation of the percentage of repetition capacity utilized within a set. This approach enables practitioners to derive RIR from an objective measure of actual effort, thereby enhancing the precision of RT prescription and monitoring.</p>","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"102 ","pages":"259-266"},"PeriodicalIF":4.0,"publicationDate":"2026-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13215239/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148054827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nebahat Eler, Tevfik Cem Akalın, Serdar Eler, Marko Joksimovic
{"title":"Data-Driven External-Load Analytics: Integrating Cluster Analysis and ACWR Monitoring in Elite Handball.","authors":"Nebahat Eler, Tevfik Cem Akalın, Serdar Eler, Marko Joksimovic","doi":"10.5114/jhk/217125","DOIUrl":"10.5114/jhk/217125","url":null,"abstract":"<p><p>The aim of this study was to characterize multidimensional external-load profiles obtained from sensor-based tracking data over a four-month competitive period in an elite men's handball team and to investigate their associations with the session type, the playing position, and weekly workload fluctuations, as measured by the acute:chronic workload ratio (ACWR). Data were collected from 23 elite players using an ultra-wideband tracking system. Six variables, i.e., total distance, maximum speed, accumulated acceleration load (AAL), the number of exertions, maximum jump height, and the number of jumps ≥0.30 m, were standardized and clustered using k-means (k = 4). The cluster with the highest composite z-score was defined as a high load. The association between weekly density of high-load sessions and the likelihood of an ACWR spike (≥1.30) was tested using logistic regression. Results showed that match sessions were 1.8 times more likely than training sessions to fall into the high-load cluster. Wings and center-backs were significantly more represented in high-load clusters than goalkeepers and pivots. Additionally, when 15% or more of the previous week's sessions were classified as of the high load, the odds of an ACWR spike in the following week increased by 10.7 times. These findings suggest that data-driven (unsupervised) clustering of external-load variables supports early identification of high-risk workload patterns. Monitoring the weekly distribution of high-load sessions may help mitigate fatigue-related maladaptation by enabling proactive, position-specific load management in elite handball.</p>","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"101 Spec","pages":"119-132"},"PeriodicalIF":4.0,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13112154/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147773596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Karol Skotniczny, Jan Walencik, Szymon Siatkowski, Jakub Chycki
{"title":"Core-Perception Coupling: Relationships among Core Temperature, the Rating of Perceived Exertion, and Thirst during Moderate Continuous Exercise under Different Hydration Status.","authors":"Karol Skotniczny, Jan Walencik, Szymon Siatkowski, Jakub Chycki","doi":"10.5114/jhk/220099","DOIUrl":"10.5114/jhk/220099","url":null,"abstract":"<p><p>Hydration status modulates both exercise performance capacity and exercise tolerance. This study aimed to examine within-trial relationships among core temperature (Tc), ratings of perceived exertion (RPE), and thirst during moderate continuous cycling, and to test whether baseline hydration status would moderate these associations. Thirty trained men (34.7 ± 6.1 years; VO<sub>2</sub>max 48.8 ± 5.8 ml·kg⁻<sup>1</sup>·min⁻<sup>1</sup>) completed up to 120 min of cycling at 50% Wmax under thermoneutral conditions. Participants were randomized to an experimental group receiving structured hydration counseling (EXP, n = 16) or a control group following habitual fluid intake (CON, n = 14). Hydration status was verified via urine specific gravity; Tc (CORE heat-flux sensor), the heart rate, RPE (0-10), and thirst (0¬-10) were recorded every 15 min. Analyses included repeated-measures tests, Spearman correlations, and ANCOVA adjusting for baselines and VO<sub>2</sub>max. Tc rose from rest and tended to plateau by ~60-75 min, whereas RPE and thirst increased throughout. Hydration status predicted higher RPE (partial η<sup>2</sup> = 0.41, p < 0.001) with Tc not independently significant (p = 0.81); VO<sub>2</sub>max was not a significant predictor, although the effect estimate suggested an inverse association with RPE (p = 0.058). For thirst, hydration status remained significant (partial η<sup>2</sup> = 0.27-0.50, p ≤ 0.005). Comparing the two groups, the CON group showed greater increases in RPE (ΔRPE mean +0.23 ± 0.05, p < 0.001; ΔRPE peak +0.53 ± 0.10, p < 0.001) and thirst (ΔThirst mean +0.23±0.04, p < 0.001). EXP participants more often completed the 120-min trial (75.0% vs. 28.6%; χ<sup>2</sup> = 10.57, p = 0.014). Perceptual coupling was strong (ΔRPE-ΔThirst r_s≈0.84), with ΔRPE inversely related to VO<sub>2</sub>max and ΔTc modestly. Starting exercise euhydrated reduces perceived effort and thirst during prolonged, thermoneutral cycling, while Tc per se adds little explanatory power for RPE after adjustment. Simple field markers (thirst, heart rate) can flag emerging strain, particularly in less fit individuals.</p>","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"101 Spec","pages":"317-338"},"PeriodicalIF":4.0,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13112159/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147773553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kinga Łosińska, Paweł Cięszczyk, Adam Zajac, Jarosław Markowski, Jan Pilch, Wojciech Smółka, Adam Maszczyk
{"title":"Genes and Injuries in Sports: A Systematic Review and Meta-Analysis.","authors":"Kinga Łosińska, Paweł Cięszczyk, Adam Zajac, Jarosław Markowski, Jan Pilch, Wojciech Smółka, Adam Maszczyk","doi":"10.5114/jhk/218951","DOIUrl":"10.5114/jhk/218951","url":null,"abstract":"<p><p>Sports injuries are a significant concern for both professional and recreational athletes, influencing performance, longevity, and rehabilitation outcomes. While external factors such as biomechanics and workload management have been extensively studied, emerging research highlights the role of genetic predispositions in injury susceptibility. This systematic review and meta-analysis consolidated findings from 24 studies examining the association between genetic polymorphisms and sports-related injuries, with a focus on musculoskeletal tissue integrity, muscle function, and inflammatory response. The analysis identified key genetic markers, including COL1A1, COL5A1, and ACTN3, associated with ligament and tendon injuries, as well as the impact of cytokine gene variants (IL-6, TNF-α) on recovery processes. The pooled odds ratio suggested a significantly increased risk of injury among individuals carrying specific genetic variants. Subgroup analyses further revealed gene-specific effects on the injury type and athlete classification. Despite these insights, gene-environment interactions and methodological variability remain challenges in fully elucidating genetic contributions to injury risk. The findings underscore the potential for personalized injury prevention strategies based on genetic screening, enhancing both sports performance and rehabilitation efficiency.</p>","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"101 Spec","pages":"179-198"},"PeriodicalIF":4.0,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13112171/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147773588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Karol Skotniczny, Michał Toborek, Artur Terbalyan, Adam Zając, Mateusz Gawełczyk, Szymon Siatkowski, Jakub Chycki
{"title":"Pre-Exercise Hydration Modulates the Sweat Rate and Executive Control during Moderate Exercise to 3% Dehydration under Thermoneutral Conditions.","authors":"Karol Skotniczny, Michał Toborek, Artur Terbalyan, Adam Zając, Mateusz Gawełczyk, Szymon Siatkowski, Jakub Chycki","doi":"10.5114/jhk/220097","DOIUrl":"10.5114/jhk/220097","url":null,"abstract":"<p><p>Dehydration impairs endurance and may compromise cognition, yet the impact of pre-exercise hydration status on thermoregulation and cognitive function during continuous exercise is not well defined. Thirty physically active men were randomized to be tested either well-hydrated (HYD; n = 16) or insufficiently hydrated (HYP; n = 14), classified by fasting urine specific gravity (USG; HYD < 1.018; HYP > 1.018) verified over three weeks. On the experimental day, participants cycled at 50% maximal power output (Wmax) under thermoneutral conditions (22°C, 45% RH) until 3% body-mass loss or for 120 min. Core temperature (Tc) was recorded continuously, the sweat rate (SR) was derived from nude body-mass change, and executive function (Stroop Interference) along with visuospatial working memory (Corsi Block-Tapping) were assessed pre- and post-exercise. Participants in the HYD group produced a higher SR (ΔSRmean +0.30 L·h⁻<sup>1</sup>, 95% CI 0.18-0.43; ΔSRpeak +0.34 L·h⁻<sup>1</sup>, 95% CI 0.04-0.63) and were more likely to reach 3% mass loss (10/16 vs. 1/14; p = 0.002). Despite greater sudomotor output, early Tc burden (0-90 min) did not differ between groups. Hydration status selectively affected executive control: Stroop naming interference showed a time × status interaction (F(1,27) = 4.57, p = 0.042), driven by slowing in HYP participants (≈+63 ms, p = 0.029), whereas Corsi indices were unchanged. These findings support targeting euhydration before prolonged exercise (e.g., morning USG <1.018), as inadequate baseline hydration may impair inhibitory control even when early Tc responses are comparable. Accordingly, for training or competition requiring rapid decision-making and attentional control, pre-exercise hydration strategies (planned fluid intake and/or USG-based monitoring) may be warranted to mitigate decrements in executive function.</p>","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"101 Spec","pages":"285-303"},"PeriodicalIF":4.0,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13112172/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147773564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oihan Esnal-Arrizabalaga, Ibai Garcia-Tabar, Asier Gonzalez-Artetxe, Asier Los Arcos
{"title":"The dRM-Index: Applicability of the Differential Respiratory-to-Muscular Training Load Index in Young Female Soccer Players.","authors":"Oihan Esnal-Arrizabalaga, Ibai Garcia-Tabar, Asier Gonzalez-Artetxe, Asier Los Arcos","doi":"10.5114/jhk/211330","DOIUrl":"10.5114/jhk/211330","url":null,"abstract":"<p><p>This study described the differential respiratory and muscular perceived training loads (RPEres-TL and RPEmus-TL) within and between sessions, and investigated the associations between neuromuscular performance and the dRM-Index (i.e., the ratio of differential respiratory and muscular perceived training loads: RPEres-TL divided by RPEmus-TL) among youth female soccer players. Thirteen outfield players (age: 17 ± 1 years) of the third team of a Women's Soccer Spanish First Division Club completed the 14-week study period. Neuromuscular performance tests (countermovement jump [CMJ], CMJ arm swing, single leg CMJ, and 30-m sprint tests) were conducted before (T1) and after (T2) the study period. Players improved neuromuscular performance (p < 0.05; Cohen's d < 1.29; small-to-large) from T1 to T2. RPEres-TL was greater than RPEmus-TL for training sessions performed four (M-4: p < 0.001; Cohen's d = -0.61; moderate) and one (M-1: p = 0.01; Cohen's d = -0.37; small) days before the match. Baseline sprint performance showed large correlations with the dRM-Index during M-2 (p < 0.05; r < 0.59), M-1 (p < 0.05; r < 0.60) and matches (p < 0.05, r < 0.66). Differential RPE allows the analysis of the TL distribution during the week providing additional insights into the training workload. Baseline sprint performance can be used to forecast the differed heterogeneous individual cardiovascular and neuromuscular responses to the sessions. This initial study on the dRM-Index offers a novel and practical approach to individualize and optimize the training process of youth female soccer players.</p>","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"101 Spec","pages":"73-86"},"PeriodicalIF":4.0,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13112166/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147773560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muhammet Yılmaz, Halit Harmancı, Filiz Özyiğit, Muhammed M Atakan
{"title":"Dose-Dependent Effects of Astaxanthin on Exercise-Induced Muscle Damage in Exercising Males.","authors":"Muhammet Yılmaz, Halit Harmancı, Filiz Özyiğit, Muhammed M Atakan","doi":"10.5114/jhk/210201","DOIUrl":"10.5114/jhk/210201","url":null,"abstract":"<p><p>Astaxanthin (AX) is a potent antioxidant and an anti-inflammatory carotenoid. Research examining whether AX could counteract exercise-induced muscle damage and improve exercise capacity has reported inconsistent results. The aim of this study was to test the efficacy of high-dose versus low-dose AX supplementation for four weeks on muscle damage markers, total antioxidant status, and a subjective marker of muscle pain following exhaustive exercise. A total of 24 active males were randomly assigned to one of the three groups: an AX12 group (12 mg·day<sup>-1</sup>; n = 8), an AX36 group (36 mg·day<sup>-1</sup>; n = 9) or a placebo group (PLC, n = 7). After four weeks of supplementation, blood samples were collected at rest, and at 2, 24, 48, and 72 h following eccentric arm exercise performed at 85% of the predetermined one-repetition maximum to assess muscle damage markers and total antioxidant status, and muscle pain levels were evaluated using a Numerical Visual Pain Scale<sub>0-10</sub>. Creatine kinase activity was significantly lower in AX groups compared to the PLC group at 24, 48, and 72 h post-exercise (p < 0.05), with no difference between both AX groups (p > 0.05). At 24, 48, and 72 h post-exercise, lactate dehydrogenase activity in the PLC group was higher than in AX12 and AX36 groups, averaging 2.2 and 2.8 times higher, respectively; however, these differences were not statistically significant (p > 0.05). A significant time effect of the muscle pain score was noted at 2, 24, 48, and 72 h post-exercise (p < 0.001), with no significant differences among the supplementation protocols (p > 0.05). In conclusion, four-week AX supplementation at a dose of 12 or 36 mg·day<sup>-1</sup> similarly reduces plasma creatine kinase activity following exhaustive exercise, yet its impact on muscle pain and antioxidant status remains limited.</p>","PeriodicalId":16055,"journal":{"name":"Journal of Human Kinetics","volume":"101 Spec","pages":"103-117"},"PeriodicalIF":4.0,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13112163/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147773647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}