International journal of sports physiology and performance最新文献

{"title":"Evolution of Mental Fatigue With Consecutive Match Progression in Elite Fencing.","authors":"Chao Bian, Suzanna Russell, Rafael Lima Kons, Steven Provyn, Jelle Habay, Špela Bogataj, Bart Roelands","doi":"10.1123/ijspp.2025-0299","DOIUrl":"https://doi.org/10.1123/ijspp.2025-0299","url":null,"abstract":"<p><strong>Purpose: </strong>On-field daily monitoring has investigated the acute and cumulative nature of mental fatigue (MF) across various sport training/competitions. However, the evolution of MF under congested 1-day match schedules and its relationship with competitive performance, particularly in elite fencing, remains underexplored.</p><p><strong>Methods: </strong>A longitudinal study monitored 31 (7 epee, 13 foil, 11 saber; 15 female) elite fencers' subjective MF in the morning (MVAS0) and immediately after each match (MVASi, measurement point i coded as match order) throughout the national competition day until elimination. Weighted least-squares regression with sample-size-based weighting was applied to capture the evolution trend throughout the day. A linear mixed-effects model explored the potential influence of performance statistics (total hits; hits difference) per match and the progression (i) on dynamic changes in MF (MVASi vs MVASi-1).</p><p><strong>Results: </strong>The competition day of 31 fencers, totaling 153 matches, was analyzed. A downward, quadratic model showed that MF accumulated with a decelerating trend as the competition progressed (theoretical increase rate between matches reduced from +22.0% to +0.5%). In each match, only hits difference (estimate = -0.581, P < .001) negatively affected MF accumulation.</p><p><strong>Conclusions: </strong>The present findings regarding intraday MF evolution in elite fencing suggest that practitioners should explore the benefit of proactive countermeasures and recovery strategies from the early rounds of a competition day. Applying real-time monitoring and MF-targeted interventions along with other motivational, emotional adjustments is critical to mitigate MF buildup and maintain performance capacity, particularly when a fencer is successively receiving hits.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1-8"},"PeriodicalIF":4.3,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145080692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Associations Between Body Composition and Performance in Elite Endurance Athletes.","authors":"Oona Kettunen, Jussi Mikkola, Johanna K Ihalainen","doi":"10.1123/ijspp.2024-0506","DOIUrl":"https://doi.org/10.1123/ijspp.2024-0506","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate if elite endurance athletes periodized their body mass (BM) and composition from preparation (T1) to specific preparation period (T2) and if changes in BM and body composition were associated with improved endurance performance.</p><p><strong>Methods: </strong>Fifty-two elite endurance athletes participated in this study. Thirteen cross-country skiers, 7 biathletes, and 3 Nordic Combined athletes formed a group of skiers (16 men and 7 women), and 5 endurance runners, 22 orienteers, and 2 triathletes formed a group of runners (17 men and 12 women). Anthropometric (dual-energy X-ray absorptiometry) and performance (sport-specific incremental treadmill test) measurements were completed in T1 and T2.</p><p><strong>Results: </strong>No changes in BM or body composition were detected from T1 to T2 except for lean mass (LM), which increased in only runners (P = .03). Peak running speed (Vpeak; P < .001) and relative peak oxygen uptake (P = .04) increased from T1 to T2 regardless of the sport or sex. Decreased body fat mass and percentage were associated with increased Vpeak (r = -.41, P = .002; r = -.45, P < .001) and relative peak oxygen uptake (r = -.31, P = .03; r = -.32, P = .02). Changes in LM were positively associated with changes in Vpeak in female skiers (r = .80, P = .03), while almost all the female runners increased both LM and Vpeak.</p><p><strong>Conclusions: </strong>Elite endurance athletes did not systematically periodize their BM from T1 to T2. Decreases in body fat mass and percentage may be beneficial for endurance performance. Since increases in LM were associated with improved endurance performance in female athletes, body-composition manipulations should not lead to a decrease in LM.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1-8"},"PeriodicalIF":4.3,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145080735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hot-Water Immersion Enhances Vertical-Jump Performance, Lower-Limb Power, and Stretch-Shortening Cycle.","authors":"Patrick Rodrigues, Justin S Lawley, Gilles C F Zovilé, Diego Jaén-Carrillo","doi":"10.1123/ijspp.2025-0197","DOIUrl":"https://doi.org/10.1123/ijspp.2025-0197","url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to (a) examine the effects of hot-water immersion (HWI) on vertical-jump performance, lower-limb power, and stretch-shortening cycle responses and (b) evaluate temperature-dependent responses by comparing 2 HWI conditions (40 °C vs 42 °C).</p><p><strong>Methods: </strong>Twenty healthy, physically active participants (12 male and 8 female; age 25.1 (2.7) y; body mass index 22.6 [1.1] kg/m2) completed countermovement-jump (CMJ) and drop-jump assessments before, after, and 15 minutes after a 45-minute water-immersion session at either 34 °C (control), 40 °C, or 42 °C in a randomized order. CMJ outcomes included jump height, peak force, and peak power, while drop-jump outcomes included jump height, reactive strength index, and vertical stiffness.</p><p><strong>Results: </strong>CMJ height increased following a 45-minute HWI session at both 40 °C and 42 °C (P < .001, d = 1.09; P < .001, d = 1.77), with no differences between the 2 conditions (P = .515). Similar improvements were found for peak power and force. At 15 minutes post-water immersion, all performance measures returned to baseline and did not differ from the control condition. For the drop-jump tests, a main effect of temperature was observed. HWI at 42 °C significantly increased drop-jump height (P = .004; d = 0.71), whereas 40 °C did not (P = .205). Reactive strength index increased following both 40 °C (P = .002; d = 0.74) and 42 °C (P < .001; d = 0.91) conditions. No significant changes were observed in vertical stiffness.</p><p><strong>Conclusion: </strong>Both HWI conditions, 40 °C and 42 °C, improved CMJ performance (height, force, and power) and reactive strength index, while only HWI at 42 °C enhanced drop-jump height. These effects were transient, returning to baseline within 15 minutes postimmersion.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1-8"},"PeriodicalIF":4.3,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145075254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Muscle Typology Does Not Influence Peak-Intensity Periods, Subsequent Recovery, or Match-Running Declines Toward the End of a Match in Professional Male Football.","authors":"Freek Van de Casteele, Jan Van Haaren, Dieter Deprez, Phillip Bellinger, Clare Minahan, Eline Lievens, Wim Derave","doi":"10.1123/ijspp.2025-0116","DOIUrl":"https://doi.org/10.1123/ijspp.2025-0116","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate the influence of muscle typology on match-running decrements toward the end of the match, peak-intensity periods, and the subsequent recovery in professional male football.</p><p><strong>Methods: </strong>Muscle typology was determined in 68 Belgian First Division outfield players by measuring muscle carnosine in the soleus using proton magnetic resonance spectroscopy. Optical tracking data were collected over 241 official matches. Total match and 15-minute averages were determined for total distance (TD), high-intensity running distance (HIRD; >4.17 m·s-1), sprint distance (>6.94 m·s-1), and high-acceleration distance (>3 m·s-2). Peak-intensity periods using 15-second to 10-minute rolling averages were determined for these metrics, but the associated 5-minute recovery periods were only quantified for TD and HIRD. Linear mixed models were used to determine the effect of muscle typology on these match-running parameters while accounting for playing position.</p><p><strong>Results: </strong>Match running decreases from minutes 0 to 15 to minutes 75 to 90, and the peak-intensity periods were not related to muscle typology (P > .05). In the first minute after 15-second to 10-minute peak-intensity periods for TD and HIRD, TD was reduced by 7% to 14% compared with match average and HIRD by 33% to 59%, respectively. These reductions were not related to muscle typology (P > .05). TD and HIRD returned to match average within 2 to 3 minutes.</p><p><strong>Conclusions: </strong>Muscle typology had no effect on peak-intensity periods or on the reductions in match running that may indirectly indicate temporary fatigue or fatigue toward the end of the match.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1-10"},"PeriodicalIF":4.3,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effect of an Educational Session to Improve Knowledge About the Menstrual Cycle and Hormonal Contraceptives in Junior Endurance Athletes and Their Coaches: An Exploratory Investigation.","authors":"Guro Strøm Solli, Virginia De Martin Topranin, Kethe Marie Engen Svantorp-Tveiten, Dionne A Noordhof","doi":"10.1123/ijspp.2025-0068","DOIUrl":"https://doi.org/10.1123/ijspp.2025-0068","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate the effects of a tailored educational session about the menstrual cycle (MC) and hormonal contraceptives (HCs) on perceived knowledge, knowledge satisfaction, communication, and the coach-athlete relationship among junior endurance athletes and their coaches.</p><p><strong>Methods: </strong>Junior female cross-country skiers and biathletes (n = 36) and their coaches (n = 12) completed 2 questionnaires within an 8-week interval (PRE-POST). After 2 weeks, the intervention group (20 athletes and 6 coaches) participated in a tailored educational session designed to enhance their knowledge about the MC and HCs. The control group (16 athletes and 6 coaches) received no education on this topic.</p><p><strong>Results: </strong>Athletes and coaches in the intervention group experienced significant PRE-POST increases in perceived knowledge (estimate = 1.28, P = .002) and satisfaction (estimate = 1.20, P < .001) with their knowledge of the MC and HCs compared to the control group. Coaches had higher perceived knowledge (estimate = 1.45, P = .003) and satisfaction (estimate = 0.83, P = .041) with their knowledge of the MC than athletes. The intervention improved the degree of communication with peers (estimate = 1.02, P = .013) but not with the other role (ie, athletes' communication with coaches and vice versa; estimate = 0.12, P = .833). In addition, it improved perceived ease of communication (estimate = 0.93, P = .003). The intervention did not seem to affect the coach-athlete relationship (P > .005).</p><p><strong>Conclusion: </strong>The educational session resulted in promising effects on perceived knowledge and satisfaction with athletes' and coaches' knowledge of the MC/HCs, while also facilitating communication among athletes. Future studies should focus on implementing and evaluating more longitudinal interventions with larger sample sizes.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1-9"},"PeriodicalIF":4.3,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Critical-Speed Modeling Using Familiar Performance Tests Can Accurately Predict 1500-m Rowing-Ergometer Performance Capability.","authors":"Daniel J Astridge, Jason C Bartam, Peter Peeling, Paul S R Goods, Olivier Girard, Martyn J Binnie","doi":"10.1123/ijspp.2025-0057","DOIUrl":"https://doi.org/10.1123/ijspp.2025-0057","url":null,"abstract":"<p><strong>Purpose: </strong>To assess the accuracy of a linear critical-speed model for predicting maximal rowing-ergometer performance.</p><p><strong>Methods: </strong>Twenty (5 female) highly trained rowers completed 5 ergometer time trials (TTs). The linear distance-time relationship between the 2000-m and the fastest of two 500-m TTs was used to predict 1500-m performance. Two time-to-exhaustion (TTE) trials, with intensity targets set to the predicted 1500-m performance capacity, were subsequently performed. The accuracy of the critical-speed model was assessed by comparing predicted and actual distances in each athlete's longest TTE trial, using absolute and percentage differences, standard error of estimate, and coefficient of variation.</p><p><strong>Results: </strong>The mean difference in 500-m TT completion time was 1.2 (1.0) seconds (1.3% [1.1%]). Athletes maintained 98.6% (0.9%) of target power output during the TTE trials, covering an average distance of 1587 (169) m. The predicted distance was 1589 (162) m. The mean difference between predicted and actual distances covered was 7.6 (6.6) m (0.4% [0.4%]), with a near-perfect association (R2 = .99). The standard error of estimate was 8.3 m, and the coefficient of variation was 0.3% between the modeled and actual TTE trial distances.</p><p><strong>Conclusions: </strong>The linear critical-speed model, based on 2 familiar and reliable performance tests, accurately predicts maximum rowing performance. These outcomes allow continued focus on 2000-m performance preparation while indirectly tracking 1500-m performance progression. In addition, this model allows for understanding of the influence that improvement in either 2000- or 500-m TT times has on predicted 1500-m performance.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1-7"},"PeriodicalIF":4.3,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145040044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Are You as Tired as I Am? Mental Fatigue Perception in Female Australian Rules Football Athletes Over a Season: The Influence of Personality.","authors":"Svenja Wirtz, Minh Huynh, Megan Smith, Kate E Webster, Clare MacMahon","doi":"10.1123/ijspp.2025-0062","DOIUrl":"https://doi.org/10.1123/ijspp.2025-0062","url":null,"abstract":"<p><strong>Purpose: </strong>Research on mental fatigue and its impact on sport performance has gained significant attention in sport science. A reoccurring observation in these studies is the variation among participants in terms of mental-fatigue perception, as well as impact on performance. Thus, this study investigated personality traits as moderators of these interindividual differences.</p><p><strong>Methods: </strong>Athlete self-report measures of mental fatigue and well-being were recorded throughout the 2023 season of 1 female Australian Rules Football team using a 5-point Likert scale, alongside a personality-trait questionnaire assessing levels of openness, conscientiousness, extraversion, agreeableness, and neuroticism.</p><p><strong>Results: </strong>Mental-fatigue levels fluctuated across the season, with game days presenting significantly (P < .05) lower levels than training days. Repeated-measurements correlations indicated that mental fatigue was positively correlated with wellness ratings of stress (r = .27), sleep (r = .20), soreness (r = .07), and readiness (r = .10). The personality traits of extraversion and openness moderated mental-fatigue levels with a significant negative association for extraversion (P < .001) and a positive association for openness (P < .001).</p><p><strong>Conclusion: </strong>The findings suggest that mental fatigue is a considerable factor in the elite athletic environment. Extraversion and openness moderate perceived mental fatigue across a season. These findings underscore the importance of considering individual differences when interpreting subjective fatigue and when designing support strategies for athletes.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1-7"},"PeriodicalIF":4.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145029672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isokinetic Total Work and Mitochondrial Oxidative Capacity Are Correlated in Appraising Hamstrings Endurance Performance of Young, Healthy, and Highly Active Adults.","authors":"Jigar Gosalia, Alaina Demalis, Jocelyn M Spicuzza, Matthew J Studinski, Kevin K McCully, Wayne J Sebastianelli, Swapan Mookerjee, David N Proctor, Giampietro L Vairo","doi":"10.1123/ijspp.2024-0304","DOIUrl":"https://doi.org/10.1123/ijspp.2024-0304","url":null,"abstract":"<p><strong>Purpose: </strong>To assess the association between skeletal-muscle endurance performance and mitochondrial oxidative capacity of the hamstrings as respectively measured by biomechanical and physiological standards.</p><p><strong>Methods: </strong>Nineteen (12 men and 7 women) healthy, young, recreationally active participants enrolled in our study. Participant characteristics comprised a mean and SD age of 21.3 (3.4) years, body mass index of 22 (3.3) kg/m2, hamstrings adipose tissue thickness of 13.1 (4.2) mm, and International Physical Activity Questionnaire score of 3692 (1528) metabolic equivalent-min/wk. Isokinetic dynamometry quantified total work, normalized to body mass (in joules per kilogram), performed by the hamstrings through a maximal number of dynamic contractions at 240°/s produced over 45 seconds. Near-infrared spectroscopy calculated the recovery of oxygen consumption rate, yielding the k (per minute) constant. The means of bilateral measures were analyzed. The Pearson product-moment correlation coefficient assessed the relation between normalized total work and k. Statistical significance was denoted as P < .05.</p><p><strong>Results: </strong>Data displayed a normal distribution and randomness. The mean and SD were 69.2 (22.4) J/kg for muscle endurance and 1.78 (0.26)/min for mitochondrial oxidative capacity. There was a significant positive linear association (r = .68, P = .001) between isokinetic-dynamometry-derived normalized total work and near-infrared spectroscopy k values for the hamstrings, which can be regarded as moderately strong.</p><p><strong>Conclusions: </strong>The isokinetic dynamometry protocol described is applicable to infer mitochondrial oxidative capacity underpinning hamstrings endurance performance in young, healthy, highly active adults. Muscle oximetry is useful for inferring total work propensity of the hamstrings in these individuals.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1-6"},"PeriodicalIF":4.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145029629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Repeated-Sprint Training in Hypoxia in Female National-Level Rugby Union Players.","authors":"Mélanie Babalian, Franck Brocherie, Cyril Catala, Romain Loursac, Marie Chambion-Diaz, Grégoire P Millet, Vincent Pialoux","doi":"10.1123/ijspp.2024-0545","DOIUrl":"https://doi.org/10.1123/ijspp.2024-0545","url":null,"abstract":"<p><strong>Purpose: </strong>The aim of this study was to investigate the effects of repeated-sprint training in hypoxia (RSH) versus in normoxia (RSN) in female national-level rugby union players.</p><p><strong>Methods: </strong>In a randomized, controlled, and crossover study, 8 female rugby union players performed 5 sessions of repeated sprints either in normobaric hypoxia (RSH, simulated altitude: 3000 m; FiO2 = 14.5%) or in normoxia (RSN, terrestrial altitude: 165 m; FiO2 = 20.5%). Before (Pre) and after (Post) training, repeated-sprint ability (6 × 10-s \"all-out\" sprints and 20-s recovery) was evaluated on a cycle ergometer.</p><p><strong>Results: </strong>From Pre to Post, peak power output was improved in RSH (602 [98] vs 704 [92] W; P = .007) but not in RSN (661 [91] vs 673 [76] W; P = .560). Similarly, mean power output was enhanced in RSH (445 [63] vs 532 [51] W; P = .013) but not in RSN (499 [88] vs 509 [63] W; P = .557). Sprint decrement did not change in either RSH (24.5 [8.9] vs. 24.0% [5.7%]; P = .819) or RSN (22.7 [5.9] vs 24.3% [4.8%]; P = .336).</p><p><strong>Conclusion: </strong>As few as 5 sessions of RSH were beneficial for improving peak and mean power outputs during repeated-sprint exercise in female national-level rugby union players compared with the same training in normoxia.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1-5"},"PeriodicalIF":4.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145029654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute Metabolic and Muscle Oxygenation Responses to Different Eccentric Tempos Under a Fixed Velocity-Loss Threshold in Squat.","authors":"Kuan-Tsen Yeh, Hung-Wen Liu, Hao-Chien Cheng","doi":"10.1123/ijspp.2025-0140","DOIUrl":"https://doi.org/10.1123/ijspp.2025-0140","url":null,"abstract":"<p><strong>Purpose: </strong>This study explored the acute physiological effects of different eccentric tempos, explosive speed (EXP), volitional speed, and 4-second tempo during 5 sets of velocity-based squat training.</p><p><strong>Methods: </strong>Twelve healthy males performed parallel squats under 3 eccentric conditions using a randomized crossover design. Each session included 5 sets at a relative load, initiated with a concentric mean velocity of 0.70 m·s-1, continuing until 20% velocity loss, with 300-second rest intervals. Blood lactate concentration was measured preexercise and postexercise each set, while changes in muscle tissue saturation index, deoxygenated hemoglobin, oxygenated hemoglobin, and total hemoglobin were continuously monitored during training using near-infrared spectroscopy.</p><p><strong>Results: </strong>The 4-second eccentric tempo resulted in significantly greater increase in lactate than EXP (3.82 [1.0] vs 2.89 [0.8] mmol·L-1, P = .002) and a higher area under the curve of lactate (4 s: 112.9 [22.8] vs EXP: 93.8 [25.1] mmol·L-1·min, P = .003, d = 1.02). Changes in tissue saturation index, deoxygenated hemoglobin, and oxygenated hemoglobin and time under tension were significantly higher in the 4-second trial than in the EXP and volitional speed trials (P < .05). No significant differences were observed in the changes in total hemoglobin, number of repetitions, training volume, mean velocity, mean power, or subjective perceptions (P > .05).</p><p><strong>Conclusions: </strong>A 4-second eccentric tempo induces greater metabolic and oxygenation responses under identical velocity-loss conditions while preserving power output and subjective perceptions. These findings highlight eccentric velocity as a key variable in velocity-based training, particularly for optimizing metabolic stress and training adaptations.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1-8"},"PeriodicalIF":4.3,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145029651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}