Biology of Sport最新文献

{"title":"A professional assessment of training plans for muscle hypertrophy and maximal strength developed by generative artificial intelligence.","authors":"Tim Havers, Caroline Jelonnek, Lukas Masur, Eduard Isenmann, Billy Sperlich, Stephan Geisler, Peter Düking","doi":"10.5114/biolsport.2026.152350","DOIUrl":"10.5114/biolsport.2026.152350","url":null,"abstract":"<p><p>The aim of this study was to evaluate the quality of resistance training plans for muscle hypertrophy and maximal strength generated by three large language models (LLMs): GPT-3.5 (via ChatGPT and Microsoft Copilot) and Google Gemini (GG). A total of 10 experienced coaches, each with at least a bachelor's degree in exercise science and at least 2 years of coaching experience, rated these plans on a 1-5 Likert scale based on 27 criteria essential for effective training plan design. The LLMs were accessed on April 30, 2024, with a prompt structure that included key training objectives and the training history of a fictional advanced trainee. Results showed that the overall quality of the LLM-generated training plans was moderate. GG outperformed GPT-3.5 (via ChatGPT and Microsoft Copilot) for hypertrophy-related plans on 2 out of 27 criteria (advanced exercise methods, recovery strategies; p < 0.05), while GPT-3.5 (via Microsoft Copilot) outperformed GG for strength-related plans on 1 out of 27 criteria (testing procedure; p < 0.05). Across all criteria, GG received ratings > 3 more frequently than GPT-3.5 (via ChatGPT and Microsoft Copilot), particularly for general aspects, training principles, and training methods. Differences between hypertrophy- and strength-oriented plans within each LLM were minimal, although GPT-3.5 (via ChatGPT) showed the most inconsistency in ratings. Although LLM-generated plans can serve as an initial framework for hypertrophy and strength development, expert supervision remains crucial to refine these plans, as LLMs cannot account for individual responses to training, safety considerations, and the complex physiological adaptation processes observed by experienced coaches.</p>","PeriodicalId":55365,"journal":{"name":"Biology of Sport","volume":"42 4","pages":"353-366"},"PeriodicalIF":4.2,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12492345/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145234358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Do players in Spanish professional soccer leagues maintain match running performance until the end of the match? A 5-minute interval analysis by match participation.","authors":"Tomás García-Calvo, David Lobo-Triviño, José C Ponce-Bordón, Borja Sanabria-Pino, Roberto López Del Campo, Ricardo Resta, Paweł Chmura","doi":"10.5114/biolsport.2025.151645","DOIUrl":"10.5114/biolsport.2025.151645","url":null,"abstract":"<p><p>The present study aimed to analyse the match running performance differences across 5-minute time intervals considering the players' participation in matches. A total of 381,194 individual match observations from professional soccer players competing in the First (n = 171,957) and Second (n = 209,237) Spanish soccer leagues over the 2022/23 season were collected. Soccer players were classified according to their participation in matches. Total distance (TD), very high-speed running (VHSR, 21-24 km × h^-1), and sprinting speed running distance (Sprint, > 24 km × h^-1) were analysed using a computerized tracking system (TRACAB, Chyronhego, New York, NY). Match data were divided into pre-defined 5-minute intervals. Linear mixed models were performed to analyse match running performance over the 5-minute intervals while controlling the influence of match participation. The main results showed a decrease in match running performance as the match time progressed, from the 55^th-60^th minute onward (p < .001), although match participation also had a significant influence. Specifically, substitute players covered significantly greater VHSR (p < .001) and Sprint distances (p < .001) than the rest of the players during their time of participation. These findings provide knowledge about the evolution of match running performance over match time. Finally, analysis of 5-minute intervals may help coaches understand the periods of matches where player substitutions are most effective.</p>","PeriodicalId":55365,"journal":{"name":"Biology of Sport","volume":"42 4","pages":"345-352"},"PeriodicalIF":4.2,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12490322/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145233850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Are decorin gene variants associated with anterior cruciate ligament rupture susceptibility?","authors":"Kinga Łosińska, Agata Rzeszutko-Bełzowska, Krzysztof Ficek, Alison V September","doi":"10.5114/biolsport.2025.152112","DOIUrl":"10.5114/biolsport.2025.152112","url":null,"abstract":"<p><p>This study aimed to investigate whether two DCN gene single nucleotide polymorphisms (SNPs), rs13312816 (T > A) and rs516115 (A > G), are associated with the risk and severity of anterior cruciate ligament (ACL) injury. A total of 296 physically active, unrelated Caucasian males participated: 160 with noncontact ACL injuries and 136 healthy controls. Genotyping was conducted using TaqMan assays. Logistic regression and haplotype-based analyses were performed, adjusting for age and body mass. The minor A allele of rs13312816 was significantly more frequent in ACL cases than in controls (8.54% vs. 2.94%, P = 0.0047; OR = 3.08, 95% CI: 1.33-7.98). Individuals with the A/T genotype had higher odds of injury compared to T/T carriers (P_adj = 0.008; OR = 3.3, 95% CI: 1.44-7.53). No associations were found for rs516115 in the case- control comparison. Haplotype analysis showed that individuals with the [A;G] haplotype had increased odds of ACL injury (P_adj = 0.0095; OR = 3.29, 95% CI: 1.44-7.52). Within the injured group, rs13312816 A/T genotype was associated with multiple injuries (ACLF) (P_adj = 0.010; OR = 3.19, 95% CI: 1.36-7.48). For rs516115, both A/G (P_adjj < 0.0001; OR = 6.03, 95% CI: 2.83-12.83) and G/G genotypes (P_adj < 0.0001; OR = 9.71, 95% CI: 2.57-36.77) were linked to ACLF. Haplotype analysis confirmed increased odds for multiple injuries in carriers of [A;G] (P_adj = 0.0099; OR = 3.34, 95% CI: 1.33-8.35) and [T;G] haplotypes (P_adj < 0.0001; OR = 4.79, 95% CI: 2.35-9.79). These findings suggest that DCN genetic variants, especially rs13312816 and specific haplotypes, contribute to ACL injury susceptibility and recurrence.</p>","PeriodicalId":55365,"journal":{"name":"Biology of Sport","volume":"42 4","pages":"333-343"},"PeriodicalIF":4.2,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12490320/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145234332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Association between physical activity, weight - adjusted waist index, and all - cause mortality in Chinese older adults: a national community - based cohort study.","authors":"Kexin Ren, Yuan Tao, Meihong Wang","doi":"10.5114/biolsport.2025.151659","DOIUrl":"10.5114/biolsport.2025.151659","url":null,"abstract":"<p><p>Enhancing physical activity and managing body weight are crucial for addressing aging-related challenges. However, research on the relationship between physical activity, Weight-Adjusted Waist Index (WWI), and all-cause mortality is limited. This study aims to explore these interactions and their impact on elderly health. Data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) for 2011-2018 included 7,034 residents aged ≥ 60 years. We utilized Cox proportional hazard models to assess the relationships between physical activity, WWI, and all-cause mortality, supplemented by subgroup analyses and interaction tests. We did a mediation analysis to assess how much of the effect of physical activity on survival status was mediated through WWI. Active individuals and those transitioning from inactive to active lifestyles exhibited significantly lower all-cause mortality risks, with reductions of 26% (HR = 0.74, CI: 0.65-0.83) and 9% (HR = 0.91, CI: 0.83-0.99), respectively. A positive correlation was found between WWI and all-cause mortality, with a threshold of 11.38 cm/√kg indicating increased risk. Although no interaction between physical activity and WWI was observed (P = 0.462), mediation analysis showed that 3.06% of the effect of physical activity on survival status was mediated through WWI. Maintaining physical activity or transitioning from a sedentary lifestyle to an active one can significantly reduce all-cause mortality in the elderly. Moreover, high WWI is associated with an increased risk of death. Importantly, WWI partially mediates the relationship between physical activity and death, shedding light on why physical activity reduces mortality and reinforcing the need for health promotion strategies tailored to the elderly population.</p>","PeriodicalId":55365,"journal":{"name":"Biology of Sport","volume":"42 4","pages":"323-331"},"PeriodicalIF":4.2,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12490307/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145233557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of daily use of intermittent pneumatic compression in competitive handball players: A randomized controlled trial.","authors":"Sergi Nuell, Jordi Rabassa, Cristina Bárcena, Josep Espar, Carles Munné, Iker García","doi":"10.5114/biolsport.2025.151656","DOIUrl":"10.5114/biolsport.2025.151656","url":null,"abstract":"<p><p>Intermittent sequential pneumatic compression (ISPC) is used to improve readiness and recovery in athletes. This study aimed to evaluate the effects of daily use of ISPC for 5 weeks on the performance, physiological, and psychological parameters in seventeen male handball players. Players were randomly assigned either to an experimental (EXP, n = 8) or a control (CON, n = 9) group. Before and after the intervention, we measured the countermovement jump (CMJ) and the agility test (T-test) as markers of sport-specific performance, the systolic blood pressure (SBP) in the brachial and ankle arteries to evaluate the hemodynamic function, and the tensiomyography of biceps femoral, gastrocnemius and vastus medialis to assess muscle function. During the intervention, the session rating of perceived effort (sRPE, 30 minutes after training) and perceived recovery status (PRS, 1 hour after waking-up the following morning) were registered to evaluate subjective recovery. Results showed that CON experienced a decrease in agility performance from pre- to post-intervention (p = 0.030). In contrast, EXP had a significant improvement in the muscle contraction delay time of the left biceps femoris (p = 0.002), and a significant decrease in ankle SBP after the intervention (p = 0.017). Regarding perceived fatigue and recovery, EXP had slightly higher values than CON in PRS (p = 0.047), while sRPE had no significant changes. Thus, daily use of intermittent pneumatic compression for 5 weeks during a training period slightly mitigates the fatigue-induced effects of training, while enhancing hemodynamic regulation and subjective recovery in competitive handball players.</p>","PeriodicalId":55365,"journal":{"name":"Biology of Sport","volume":"42 4","pages":"311-321"},"PeriodicalIF":4.2,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12490312/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145233843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Running demands during top-up conditioning sessions compared to competitive matches in elite Portuguese soccer players.","authors":"João Ribeiro, Petrus Gantois, Fabiano de Souza Fonseca, Luis Suarez-Arrones, João Viana, Fábio Yuzo Nakamura","doi":"10.5114/biolsport.2025.151650","DOIUrl":"10.5114/biolsport.2025.151650","url":null,"abstract":"<p><p>Soccer players who are non-starters typically experience reduced match loads, which can hinder their physical fitness and match readiness over time. This study aimed to investigate the running demands accumulated during top-up sessions in comparison to soccer matches. Twenty-six outfield soccer players from an elite Portuguese soccer team participated in this study. The following running variables were recorded: total distance (TD), running (14.4 to 19.7 km · h^-1), high-speed running (HSR: 19.8 to 25.1 km · h^-1), sprinting (≥ 25.2 km · h^-1) distances, number of sprints (counts), number of accelerations (ACC; 2-3 m · s^-2 and > 3 m · s^-2), decelerations (DEC; 2-3 m · s^-2 and > 3 m · s^-2), and player load. A linear mixed-effects model was used to examine differences between top-up sessions and matches. Overall, non-starters accumulated lower running load during top-up sessions than matches for most of the variables analyzed, but in particular TD (p < 0.001; ES range 2.46 to 3.74), running (p < 0.001; ES range 2.93 to 3.90), HSR (p < 0.001; ES range 2.21 to 3.47), sprints events (p < 0.001; ES range 1.16 to 2.76), ACC > 3 m · s^-2 (p < 0.005; ES range 0.98 to 1.37), DEC > 3 m · s^-2 (p < 0.001; ES range 1.91 to 2.66), and player load (p < 0.001; ES range 2.34 to 3.23). Therefore, non-starters accumulated less than half of the total match distance for most of the running metrics during top-up sessions. These findings suggest that compensatory training should be designed to more closely replicate match demands, with particular attention to high-intensity demands, such as HSR and sprints.</p>","PeriodicalId":55365,"journal":{"name":"Biology of Sport","volume":"42 4","pages":"287-297"},"PeriodicalIF":4.2,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12490323/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145234144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Return to performance: machine learning insights into how absence time following muscle injuries affects match running performance in LaLiga soccer players.","authors":"Javier Pecci, Horacio Sánchez-Trigo, David Mancha-Triguero, Borja Sañudo, Gonzalo Reverte-Pagola, Juan José Del Ojo-López, Roberto López Del Campo, Ricardo Resta, Adrián Feria-Madueño","doi":"10.5114/biolsport.2025.151651","DOIUrl":"10.5114/biolsport.2025.151651","url":null,"abstract":"<p><p>To determine how absence time after muscle injuries affects external load metrics in elite soccer players and identify which performance variables are most impacted by the injury. A total of 110 lower limb muscle injuries from LaLiga players were analysed. Following an analysis of pre- and post-injury data to identify which outcomes were affected by muscle injury, machine learning algorithms were employed to examine relationships between absence duration and performance metrics. Maximal speed, maximal acceleration, maximal deceleration, composite index (i.e., overall player performance) and sprint count during matches were the most affected variables after return to play. The multiple linear regression (MLR) model and random forest regression (RFR) presented an R² of 0.348 and 0.442. Maximal speed was the variable most strongly associated with absence time in both models (coefficient in MLR = 7.94; mean absolute SHAP value in RFR model = 4.99), with longer recovery periods correlating with reduced match performance in this metric. Maximal acceleration and deceleration also showed declines with increased absence time. In contrast, sprint count exhibited no significant relationship with absence time. Maximal speed, acceleration and deceleration capacity, as well as sprint count and overall performance, are affected after muscle injuries. However, prolonged recovery following muscle injuries especially reduces maximum speed and acceleration/deceleration capacity in elite players during matches, while sprinting actions remain unaffected by absence time.</p>","PeriodicalId":55365,"journal":{"name":"Biology of Sport","volume":"42 4","pages":"275-286"},"PeriodicalIF":4.2,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12490316/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145234212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Locomotor characteristics of intense accelerations according to the playing position in top Spanish football teams during competition.","authors":"Joaquín González-Rodenas, Víctor Moreno-Pérez, Adrián Castaño-Zambudio, Roberto López-Del Campo, Fabio Nevado, Juan Del Coso","doi":"10.5114/biolsport.2025.151652","DOIUrl":"10.5114/biolsport.2025.151652","url":null,"abstract":"<p><p>This study aimed to characterise the locomotor characteristics of intense relative accelerations (> 50% of maximal acceleration-speed profile) according to playing positions in top-ranked Spanish football teams. A total of 271,535 accelerations performed by 102 football players of the top four teams during the 2023-2024 LaLiga season were registered by a multiple-camera computerised tracking system (TRACAB; ChyronHego, USA). A generalized linear mixed model compared the acceleration characteristics (number, distance, duration, intensity and speed) across playing positions (central defender: CD, full back: FB, central midfielder: CM, attacking midfielder: AM, winger: W and forward: FW) considering the effect of contextual variables. CD exhibited less intense accelerations per minute than the rest of the playing positions (p < 0.05). W exhibited the greatest distance per acceleration (estimated mean (EM) = 9.08 m), longest duration (EM = 2.18 s), highest peak speed (EM = 19.5 km · h^-1), and highest speed at maximum acceleration (EM = 12.8 km · h^-1) (p < 0.05). FW exhibited the highest peak acceleration per action (EM = 3.14 m · s^-2) and average acceleration per action (EM = 1.76 m · s^-2) (p < 0.05). AM and CM registered higher initial speed (p < 0.05) and exhibited the lowest values for peak acceleration per action (p < 0.05), compared to the other playing positions. In contrast, CD and CM showed the shortest distances and slowest speeds (p < 0.05). In conclusion, W and FW exhibited higher acceleration intensity than the rest of the playing positions, while CD and CM obtained the lowest values for distance, duration, and speed.</p>","PeriodicalId":55365,"journal":{"name":"Biology of Sport","volume":"42 4","pages":"299-310"},"PeriodicalIF":4.2,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12490305/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145234141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative effects of 9-month in-season resistance training with a novel periodization approach (integral periodization) vs. a traditional approach on high-intensity actions and non-contact injuries in young, trained soccer players.","authors":"Jose Jimenez-Iglesias, Oliver Gonzalo-Skok, Mario Landi-Fernández, Alejandro Perez-Bey, Eduardo de la Pascua-Roca, Pedro Gómez Piqueras, Miguel Angel Campos-Vazquez, Jose Castro-Piñero","doi":"10.5114/biolsport.2025.151649","DOIUrl":"10.5114/biolsport.2025.151649","url":null,"abstract":"<p><p>The aim of the present study was to examine the effect of a novel periodization model - integral periodization (IP) - that considers the load balance between game-specific demands and resistance training sessions and to compare it with the effect a traditional periodization model (TP) of resistance training (RT) on fitness through lower-body muscular strength, acceleration and speed, change of direction ability, and cardiorespiratory fitness performance, in addition to non-contact injury incidence in young, trained soccer players during a full season. Forty-five (n = 21 vs n = 24) trained soccer players (15.2 ± 0.1 years) were randomly divided into a TP training group (TPG) and an IP training group (IPG). High-intensity actions (HIAs) were evaluated through countermovement jump (CMJ), squat and hip-thrust progressive loading tests, a 10-m and 30-m sprint test, a V-cut test, and a 30-15 intermittent fitness test, and non-contact injuries were recorded. In RT sessions, TPG used exercises without variability that were repeated systematically, while IPG used variable exercises for compensating the load in reference to what was experienced on the pitch. The results showed significant improvements in all tests (ES: 0.42-4.43, all p < 0.05), except the 30-15 ITF (ES: 0.21-0.27, p = 0.114-0.332), in both groups. However, IPG showed significantly better results than TPG in 10-m (p < 0.001), 30-m sprint (p < 0.001), V-cut (p < 0.012), and non-contact injuries incidence (p < 0.028). In summary, IPG showed greater HIA improvements compared to TP and reduced non-contact injury incidence in young, trained soccer players.</p>","PeriodicalId":55365,"journal":{"name":"Biology of Sport","volume":"42 4","pages":"261-274"},"PeriodicalIF":4.2,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12492344/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145233908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute effects of beetroot juice vs. creatine supplementation on maximal strength, autonomic regulation, and muscle oxygenation during incremental resistance exercise.","authors":"Atef Salem, Achraf Ammar, Mohamed Kerkeni, Mohamed Ali Boujelbane, Ayse Merve Uyar, Leonard Moritz Köbel, Saranya Selvaraj, Reza Zare, Katie M Heinrich, Haitham Jahrami, Slim Tounsi, Giuseppe Grosso, Piotr Zmijewski, Wolfgang I Schöllhorn, Khaled Trabelsi, Hamdi Chtourou","doi":"10.5114/biolsport.2025.151658","DOIUrl":"10.5114/biolsport.2025.151658","url":null,"abstract":"<p><p>This study investigated the acute effects of beetroot juice (BJ) and creatine (CR) supplementation on maximal strength, heart rate variability (HRV), and muscle oxygenation during incremental resistance exercise. Eleven physically active males (age = 21.36 ± 1.8 years) completed a randomized, double-blind, placebocontrolled, crossover protocol. Participants ingested either 0.3 g · kg^-1 of CR or 15 g of beetroot powder (7.26 mmol · L^-1 or 450 mg of nitrate) two hours before each session. The three testing sessions included bench press and back squat at 60%, 70%, and 80% of one-repetition maximum (1-RM) until failure. Repetition-tofailure, peak velocity, power, Heart rate, and muscle oxygen saturation (SmO₂) were recorded during both exercises. HRV indices, lower-limb strength performance, blood lactate, and rating of perceived exertion (RPE) were measured pre- and post-session. As intensity increased, maximum repetitions decreased significantly in all exercises and conditions (p < 0.05). Both BJ and CR improved peak velocity compared to placebo (p < 0.05). BJ led to lower peak heart rates at all intensities during BP and only at 80% of 1-RM during BS and higher SmO₂ across all intensities (p < 0.05) compared to PLA and CR. From pre- to post-session, lactate and RPE increased (p < 0.05) and lower -limb strength performance and HRV declined (p < 0.05), in all conditions, with no significant differences between BJ and CR. Compared to PLA, BJ showed significantly higher Root mean square of successive differences (RMSSD), Standard deviation of normal-to-normal intervals (SDNN), and high frequency (HF) power at both pre- and post-session (p < 0.05). CR supplementation resulted in significantly higher RMSSD values compared to PLA at both pre- and post-session time points (p < 0.001), while HF was significantly elevated only at post-session (p = 0.018), and SDNN showed no significant differences at either time point. Additionally, BJ revealed significantly higher RMSSD than CR at pre-session (p = 0.041). In conclusion, both BJ and CR significantly enhanced peak velocity during incremental resistance exercises compared to placebo. However, BJ provided additional benefits in muscle oxygenation and autonomic nervous system regulation, particularly during high-intensity efforts.</p>","PeriodicalId":55365,"journal":{"name":"Biology of Sport","volume":"42 4","pages":"241-259"},"PeriodicalIF":4.2,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12490317/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145234389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}