International journal of sports physiology and performance最新文献

{"title":"Normalizing Acceleration and Power in Elite Soccer With Acceleration-Speed Profiles: A Case Study of Game Segment, Position, and Goal Differential.","authors":"Patrick Cormier, Ming-Chang Tsai, Marc Klimstra","doi":"10.1123/ijspp.2025-0017","DOIUrl":"10.1123/ijspp.2025-0017","url":null,"abstract":"<p><strong>Purpose: </strong>Acceleration-speed (AS) profiling provides a novel way to quantify soccer players' maximum running ability without requiring dedicated sprint tests. This study explored how normalizing player effort with AS profiles could reveal unique patterns of changes in effort compared with nonnormalized absolute values during distinct goal differential conditions throughout matches and across positions.</p><p><strong>Methods: </strong>AS profiles were developed from global navigation satellite system sensor data from 3 years of match play from a women's national soccer team. Acceleration and power data were then grouped into low, moderate, high, and very high speed domains using either nonnormalized maximum values or normalized values based on individualized AS profiles. Separate linear mixed model analyses were carried out for normalized and nonnormalized data.</p><p><strong>Results: </strong>The analysis revealed that when examining changes in acceleration effort based on goal differential, both normalized and nonnormalized values showed a general increase in effort when either in a draw, or winning in the first half, and a general trend in sustained effort when losing in the first half or losing/drawn throughout the match. Furthermore, differences were mostly displayed at high to very high running-speed domains for normalized and moderate- to low-speed zones for nonnormalized metrics.</p><p><strong>Conclusions: </strong>These findings highlight the value of using individual AS and power profiles to normalize effort to facilitate investigation of player- and position-specific differences and reveal important positional behaviors displayed when in draw, losing, or winning states from first to second halves.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1079-1090"},"PeriodicalIF":4.3,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144505628","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 Making of a Biathlete: Insights From 2 Decades of Training Data From Junior, World, and Olympic Champions.","authors":"Hannes Kock, Jürgen Wick, Thomas Gronwald, Marko S Laaksonen, Helen Hanstock","doi":"10.1123/ijspp.2024-0382","DOIUrl":"10.1123/ijspp.2024-0382","url":null,"abstract":"<p><strong>Aim: </strong>To retrospectively describe the annual training characteristics of elite biathletes across different age groups over 2 decades.</p><p><strong>Methods: </strong>Self-documented training-diary data from 18 elite biathletes (tier 4/5, 7 ♀, 11 ♂) between 1994 and 2014 were included in the study and classified by age group (junior: 16-18 y, U23: 19-23 y, senior: >23 y). Linear mixed models were used to analyze the effect of age group on training characteristics (intensity, distance, time, and modality shooting training) for each sex.</p><p><strong>Results: </strong>Male biathletes increased their total training volume (TV) by 34% across age groups, while female biathletes did not show increasing TV with age. Endurance TV increased from junior to senior level by 35% and 23% in both men and women. The proportional distribution of low-intensity training, moderate-intensity training,, and high-intensity training was significantly different for both sexes between age groups. Senior male biathletes shot 4% and 15% more annual shots than Under-23s and juniors due to greater number of technical and in-competition shots, while females only increased in-competition shots at senior level.</p><p><strong>Conclusion: </strong>This study provides further insights into the biathlon training puzzle, suggesting sex-specific differences in training strategies from junior to senior level. Our data may emphasize the importance of increasing endurance TV from junior to senior level by increasing the proportion of low-intensity training, with a reduction in moderate-intensity training and maintenance of high-intensity training when transitioning between age groups. Increasing the number of technical shots, as well as in-competition shots, while maintaining precision-shooting volumes may also be important for biathletes' long-term development.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1135-1144"},"PeriodicalIF":4.3,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144484339","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":"Evaluating the Reliability and Seasonal Sensitivity of a Fitness-Testing Battery in Elite Youth Soccer.","authors":"Nikolaos D Asimakidis, Marco Beato, Chris Bishop, Anthony N Turner","doi":"10.1123/ijspp.2025-0055","DOIUrl":"10.1123/ijspp.2025-0055","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the reliability and seasonal sensitivity of a fitness-testing battery in elite youth soccer players using 2 data-treatment methods: (1) the best score of multiple trials and (2) the mean of multiple trials.</p><p><strong>Methods: </strong>Countermovement jump (CMJ), single-leg CMJ, isometric midthigh pull, Nordic hamstring strength, 10-m sprint, 505 change of direction, and the Bronco endurance test were assessed in 24 elite academy soccer players (age 17.6 [1.0] y, height 183.5 [8.5] cm, body mass 78.2 [8.5] kg) at preseason, midseason, and end of season.</p><p><strong>Results: </strong>The CMJ, Nordic hamstring strength, 10-m sprint, 505 change of direction, and Bronco tests demonstrated high sensitivity to change (signal-to-noise ratio [SNR]: 1.14-3.08), with over 60% of athletes displaying an individual SNR >1.0. In contrast, single-leg CMJ and isometric midthigh pull relative peak force exhibited the lowest reliability and sensitivity (SNR: 0.93-1.19), with less than 60% of athletes demonstrating an individual SNR >1.0, suggesting limited utility for evaluating performance changes. While the mean of multiple trials generally yielded marginally better reliability and sensitivity, both data-treatment methods were similar.</p><p><strong>Conclusions: </strong>The majority of the studied fitness tests were reliable and sensitive enough to detect meaningful changes over a season in elite youth soccer players. Practitioners can select either the best trial or mean of trials for data analysis, depending on their context. Overall, these findings illustrate the reliability and seasonal sensitivity of common fitness tests, enabling practitioners to prioritize tests that accurately monitor player performance changes.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1091-1102"},"PeriodicalIF":4.3,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144484336","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":"Intermittent Pneumatic Compression May Reduce Muscle Soreness but Does Not Improve Neuromuscular Function Following Exercise-Induced Muscle Damage: A Randomized Placebo-Controlled Trial.","authors":"Filipe Maia, Fábio Y Nakamura, Ricardo Pimenta, Sandro Tito, Henrique Sousa, João Ribeiro","doi":"10.1123/ijspp.2024-0410","DOIUrl":"10.1123/ijspp.2024-0410","url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to investigate the impact of an intermittent pneumatic compression (IPC) protocol on the recovery kinetics following exercise-induced muscle damage caused by an all-out flywheel protocol consisting of 6 sets of 12-repetition squats.</p><p><strong>Methods: </strong>Thirty-three active male university students (age 20.85 [2.8] y, height 178 [5.7] cm, body mass 75.05 [7.54] kg) were randomly assigned to either a 30-minute peristaltic IPC treatment at 200 mm Hg or a 30-minute placebo intervention (ie, simulated microcurrent treatment). Participants performed functional tests, including maximal knee extension and flexion, countermovement jump, and broad jump, and completed a perceptual soreness questionnaire before the fatigue protocol, immediately after the 30-minute recovery intervention and 24 and 48 hours postintervention. To examine the effects of the fatigue protocol and recovery interventions, a 2 × 4 repeated-measures analysis of variance was conducted, and effect sizes were calculated to assess practical relevance.</p><p><strong>Results: </strong>A significant time effect was observed for all measurements (ηp2: .216-.697; P < .05), indicating substantial fatigue from the exercise-induced-muscle-damage protocol. However, no statistically significant differences were detected between recovery interventions (ηp2: .001-.130; P: .155-.859). Notably, based on the effect-size analysis, a consistent trend toward reduced perceived soreness with IPC was observed, which may hold practical relevance for athletes (d: 0.32-0.75).</p><p><strong>Conclusions: </strong>Overall, a 30-minute IPC application immediately following exercise-induced muscle damage does not appear to improve the recovery kinetics of jumping and maximal voluntary contraction performance; however, the potential reduction in perceived soreness suggests a need for further investigation.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1103-1109"},"PeriodicalIF":4.3,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144484337","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 Impact of Unilateral and Bilateral Plyometric Training Combined With Linear Sprints on Physical Performance in Youth Male Elite Futsal Players.","authors":"Tiago A Neves, Igor Soalheiro, Ciro Winckler, Lars B Michalsik, Rodrigo Ramirez-Campillo, Ricardo L F Guerra","doi":"10.1123/ijspp.2024-0538","DOIUrl":"10.1123/ijspp.2024-0538","url":null,"abstract":"<p><strong>Purpose: </strong>To compare the effect of linear sprint training combined with plyometric training involving unilateral compared with bilateral exercises on youth male elite futsal players' physical performance.</p><p><strong>Methods: </strong>During 4 weeks of their regular futsal training routine, players were randomly distributed into groups. Plyometric training involved bipedal (BG, n = 13) or unipedal (UG, n = 11) horizontal maximum-intensity jumps, and linear sprint training involved maximal-intensity 10-m sprints. The 2 training groups completed an equal number of total jumps (n = 837) and sprints (n = 280), and the control group (CG, n = 10) worked with a futsal ball to equate temporally the training time. Players were measured in squat and countermovement jump, standing long jump, 5-multiple-bounds test, sprint (10 and 20 m), and T-test change-of-direction speed (CODS). Two-way analysis of variance (group × time) with Tukey post hoc and effect size were calculated. Significance levels were set at P < .05 for all tests.</p><p><strong>Results: </strong>No time-group interactions were noted. Time effects were noted for vertical and horizontal jumps (squat jump, countermovement jump [cm, W·kg-1], standing long jump dominant, nondominant [cm]), with moderate and mainly large (magnitude) improvements to UG and BG, and only small or ignored to CG. The sprints presented large improvements to BG (10 and 20 m) and UG (20 m) and small or moderate to CG, which was similar to the CODS (except for the ignored magnitude to CG).</p><p><strong>Conclusions: </strong>Linear sprint training combined with plyometric training involving unilateral or bilateral exercises seems to induce similar improvements in youth male futsal players' physical performance, including vertical and horizontal jump performance and linear and CODS sprint performance.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1145-1151"},"PeriodicalIF":4.3,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144484338","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 a High-Heat-Capacity Mattress Topper on Sleep in Elite Badminton Players During a Summer Training Period: Does 1 Size Fit All?","authors":"Maxime Chauvineau, Enzo Hollville, François Duforez, Gaël Guilhem, Mathieu Nedelec","doi":"10.1123/ijspp.2024-0554","DOIUrl":"10.1123/ijspp.2024-0554","url":null,"abstract":"<p><strong>Purpose: </strong>Inadequate sleep quantity or quality is common in elite athletes and may worsen with high summer temperatures. High-heat-capacity bedding systems have demonstrated beneficial effects on several sleep parameters. The present study evaluated the effect of a high-heat-capacity mattress topper (HMT) on sleep quantity and quality in elite badminton players during a summer training period.</p><p><strong>Methods: </strong>In a randomized, single-blinded, and counterbalanced order, 14 elite badminton players completed two 1-week conditions: sleeping on HMT and on a low-heat-capacity mattress topper. Sleep-wake patterns and perceived sleep quality were assessed daily using actigraphy and sleep diaries alongside nocturnal thermal comfort and sensation. Nocturnal core body temperature was monitored continuously for 2 consecutive nights per condition. Seven players also performed a 1-night polysomnography in each condition for gold-standard assessment of sleep architecture.</p><p><strong>Results: </strong>Despite a significant reduction in core body temperature (-0.037 °C, P < .001), sleeping on HMT did not affect any sleep variable or perceived sleep quality, thermal comfort, or sensation (all P > .05) compared with a low-heat-capacity mattress topper. Nevertheless, players with poorer sleep efficiency (<91.6%) and longer wake after sleep onset (>27.1 min) showed significant improvements in sleep efficiency (+1.5%, P < .01) and wake after sleep onset (-6.4 min, P < .001) relative to those wither greater values.</p><p><strong>Conclusions: </strong>This study highlights that HMT did not improve sleep quantity and quality in elite badminton players. However, it provides evidence of improved sleep efficiency and reduced wakefulness for those with more disturbed sleep, suggesting an individual approach when prescribing this sleep strategy.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1152-1160"},"PeriodicalIF":4.3,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144484335","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":"Evolution of Athlete Match Demands Across 3 Australian Football League Women's (AFLW) Seasons.","authors":"Brooke Jenner, Hunter Bennett, Steven Milanese, Jordan Sellar, Darren Burgess, John Arnold","doi":"10.1123/ijspp.2024-0414","DOIUrl":"10.1123/ijspp.2024-0414","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate the changes in match demands of Australian Football League Women's (AFLW) athletes over the past 3 seasons (2022-2023). It was hypothesized that match demands would increase across all positional groups.</p><p><strong>Methods: </strong>Forty-two athletes from 1 AFLW club who played at least 1 match across seasons 6 to 8 (2022-2023) were included. Match-day running demands including total distance (TD), speed, acceleration, high-intensity running (HIR; >19 km/h), very HIR (VHIR; >21 km/h), and sprint distances (>24 km/h) were exported from Catapult Vector S7 global positioning system units. Raw speed (in meters per minute) and acceleration (in meters per second squared) files were exported to calculate 1-minute rolling peak periods. Linear mixed-effects regression models were conducted with effect sizes (d) to examine changes in match demands over time for the cohort and playing-position groups.</p><p><strong>Results: </strong>TD increased by 344 m (d = 0.33) between seasons 6 and 7 and 971 m (d = 0.72) between seasons 7 and 8 (P < .001). HIR, VHIR, rolling 1-minute peak speed, and acceleration increased between seasons 6 and 7 by 70 m (d = 0.38), 36 m (d = 0.31), 5.1 m/min (d = 0.15), and 0.04 m/s2 (d = 0.46), respectively (P < .001), while no changes were seen between seasons 7 and 8. Total player load increased by 28 AU (d = 0.29) between seasons 6 and 7 and 80 AU (d = 0.54) between seasons 7 and 8 (P < .001).</p><p><strong>Conclusions: </strong>TD increased across seasons 6 to 8, whereas HIR, VHIR, rolling 1-minute peak speed, and acceleration only increased between seasons 6 and 7. While changes in TD may encompass factors such as rule changes, relative metrics including HIR and VHIR changed in this cohort. These findings provide a comprehensive evaluation of current AFLW match demands and will assist in future AFLW athlete preparation.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1110-1123"},"PeriodicalIF":4.3,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144475074","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":"Assessing Maximum Sprinting Speed in Female Team Sport: The Role of Sprint Distance and Timing-Gate Configuration.","authors":"Eddie McGuinness, Kris Beattie, Mark Lyons, Aoife Lane, Clement Higginbotham, Robin Healy","doi":"10.1123/ijspp.2025-0029","DOIUrl":"10.1123/ijspp.2025-0029","url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to (1) determine if differences exist in female team-sport maximum sprinting speed (MSS) using sprint distances of 30 and 40 m and split times over 5- and 10-m intervals, (2) determine the intertrial reliability of MSS using each measurement method, and (3) examine the association between sprint acceleration distance and MSS.</p><p><strong>Methods: </strong>Elite and subelite female Gaelic football players (N = 62) performed 40-m sprints with dual-beam timing gates placed every 5 m. Four measurement methods were used to determine MSS: 5-m split times over a 40-m sprint distance, 5-m splits over 30 m, 10-m split times over 40 m, and 10 -m splits over 30 m.</p><p><strong>Results: </strong>A repeated-measures analysis of variance revealed significant differences (P < .001) in MSS-derived differences from the different measurement methods with a ηp2 of .494 (large effect). MSS was significantly different between all methods (mean differences: 0.02-0.08 m·s-1; Cohen dz: 0.49-1.25). The greatest mean MSS was achieved using 5-m splits over 40 m. All MSS measurement methods had high relative and absolute reliability (intraclass correlation coefficient: .97-.98; coefficient of variations: 1.0%-1.2%; standard error of measurement: 0.07-0.08 m·s-1). There was a significant moderate positive correlation (ρ = .41) between MSS and acceleration distance.</p><p><strong>Conclusion: </strong>The highest estimate of MSS was found using 5-m splits over 40 m. All measurement methods displayed high reliability; we recommend the use of 5 -m splits over ∼30 m when assessing MSS in female team-sport athletes with timing gates.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1168-1171"},"PeriodicalIF":4.3,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144333106","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 Role of Exercise-Mode Variation in Daily Load Management Among World-Class Cross-Country Skiers.","authors":"Jacob Walther, Jan Kocbach, Øyvind Sandbakk","doi":"10.1123/ijspp.2025-0069","DOIUrl":"10.1123/ijspp.2025-0069","url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to retrospectively analyze the day-to-day mode periodization of endurance training among world-class cross-country skiers.</p><p><strong>Methods: </strong>Three hundred sixty-five days of self-reported endurance training from 17 (7 female) world-class cross-country skiers (28 [3] y) were retrospectively analyzed. The data included information on session duration, intensity, and modality (eg, skating and classical skiing, roller skiing, running, cycling, kayaking, and others) and was separated into the general preparation (GP) and competition period (CP). Mode monotony was calculated as the proportion of the most applied mode.</p><p><strong>Results: </strong>Mean weekly mode monotony was 48.3% (4.3%) during GP and 55.0% (5.2%) during CP and correlated negatively with weekly training load (r = -.5, P < .001). The time gaps between sessions with the same mode (0 [same day]/1/2/3/4/5+ d) were distributed as 5/43/25/12/6/10% during GP and 5/47/21/12/11/15% during CP. During GP, 21% of intensive sessions were performed ≥14 days after the previous intensive session in the same mode, while the remaining sessions were spread evenly across 0 to 13 days, with each interval accounting for <10%. This trend reversed during CP, with 18% (6%) of intensive sessions (including races) in the same mode on consecutive days and other time gaps ≤11%.</p><p><strong>Conclusion: </strong>This study provides new insights into the day-to-day application of different exercise modes by world-class cross-country skiers. The findings indicate high variability in exercise modes, with mode monotony rarely exceeding 50%. While skiers frequently applied the same mode with gaps of 1 to 3 days, intensive sessions using the same mode were typically separated by longer intervals, except for gaps related to competitions.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1060-1067"},"PeriodicalIF":4.3,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144333108","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":"Free-Weight and Smith-Machine Squats: Do They Produce Selective Chronic Adaptations in the Effectiveness of Force Application?","authors":"Daniel Marcos-Frutos, Sergio Miras-Moreno, Gonzalo Márquez, Amador García-Ramos","doi":"10.1123/ijspp.2025-0104","DOIUrl":"10.1123/ijspp.2025-0104","url":null,"abstract":"<p><strong>Background: </strong>Force is applied more in the backward direction during Smith-machine (SM) squats than in free-weight (FW) squats, although it is still uncertain whether this discrepancy will result in chronic adaptations in that direction.</p><p><strong>Purpose: </strong>We aimed to assess the effects of an 8-week squat training with FW or SM on longitudinal ground-reaction forces recorded during both FW and SM squats.</p><p><strong>Methods: </strong>Twenty sport-science students (9 female) were assigned to either an FW or SM training group, balanced by sex and relative strength. The 8-week training (2 sessions/wk) consisted of 4 sets of back squats at 70% of 1-repetition maximum (1-RM) with 20% velocity loss. Pretesting and posttesting assessed ground-reaction forces during a single set of 10 repetitions at ~45% and ~70% 1-RM, performed with FW in one session and SM in another session.</p><p><strong>Results: </strong>Squat type (FW or SM) had minimal influence on longitudinal impulse, its components (mean force and time), or the angle of the resultant ground-reaction force. The only significant difference was observed in longitudinal impulse during the propulsive phase at ~70% 1-RM in the SM squat (P = .037), where the FW training group exhibited a reduction in longitudinal impulse posttraining, while the SM training group showed an increase.</p><p><strong>Conclusions: </strong>An 8-week squat training does not modify the effectiveness of force application, regardless of training or testing squat type. Therefore, both squat variations can be used interchangeably without systematically influencing the direction of force production, allowing athletes to select based on preference, equipment availability, or sport-specific demands.</p>","PeriodicalId":14295,"journal":{"name":"International journal of sports physiology and performance","volume":" ","pages":"1051-1059"},"PeriodicalIF":4.3,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144333107","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}