Journal of Strength and Conditioning Research最新文献

{"title":"Manuscript Clarification for Sullivan VE, Ares AP, Cook SB. Cardiorespiratory, metabolic, and perceptual responses to blood flow restricted running in female distance runners.","authors":"Nicholas Rolnick","doi":"10.1519/JSC.0000000000005155","DOIUrl":"https://doi.org/10.1519/JSC.0000000000005155","url":null,"abstract":"","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":"39 8","pages":"949"},"PeriodicalIF":2.5,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144690618","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":"Normative Data for Preseason Screening Assessments in Female University Contemporary Dancers.","authors":"Jada L Kiss, Meghan L Critchley, Sarah J Kenny","doi":"10.1519/JSC.0000000000005153","DOIUrl":"10.1519/JSC.0000000000005153","url":null,"abstract":"<p><strong>Abstract: </strong>Kiss, JL, Critchley, ML, and Kenny, SJ. Normative data for preseason screening assessments in female university contemporary dancers. J Strength Cond Res 39(9): e1099-e1104, 2025-Injury incidence rates in elite-level dance are high. Normative values from preseason screening can inform training to target areas for improvement and minimize future injury risk. The purpose of this study was to establish mean/median values, proportions, and percentiles for hip and ankle joint range of motion, dynamic balance, and isometric hip strength in female preprofessional contemporary dancers. One hundred sixty-six dancers (mean age: 18.9 ± 1.83 years) participated in preseason screening at the beginning of 6 academic years (2015, 2018, 2019, and 2021-2023). Measures included: ankle and hip range of motion [dorsiflexion (degrees), plantarflexion (degrees), and total active standing turnout (TAT) (degrees)], dynamic balance [unipedal dynamic balance (UDB) (in seconds) and Y-balance test (YBT) (cm)], and hip abduction strength (HAS) (N, N/kg body mass). Mean dorsiflexion was 46.5° (95% confidence interval [CI]: 45.5-47.5), mean plantarflexion was 86.9° (95% CI: 85.7-88.1), and mean TAT was 105° (95% CI: 102.7-108.5). Median UDB was 4.9 seconds (IQR: 3.8-7.11). Mean YBT anterior reach was 56.0 cm (95% CI: 55.2-56.9), and mean YBT composite score was 87.0 cm (95% CI: 86.0-88.1). Mean absolute HAS was 265.9 N (95% CI: 253.4-278.4), and mean normalized HAS was 4.5 N·kg -1 body mass (95% CI: 4.3-4.7). Paired t -tests and Wilcoxon sum rank tests were used to examine side-to-side differences (α = 0.05). Percentile analysis for screening assessments was conducted. There were no side-to-side differences between dominant and nondominant legs. Female university dancers' preseason screening scores can be compared with normative data from the present study to identify areas for improvement to tailor supplementary training. Future prospective research is recommended to establish associations of these measures with dance-related injury risk.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"e1099-e1104"},"PeriodicalIF":3.0,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144506076","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":"Polyphenol-Rich Sorghum Bicolor Extract Enhances Strength Recovery After Eccentric Exercise.","authors":"Clara J Mitchinson, Minyoung Kwak, Pasquale J Succi, Brian Benitez, Haley C Bergstrom","doi":"10.1519/JSC.0000000000005144","DOIUrl":"10.1519/JSC.0000000000005144","url":null,"abstract":"<p><strong>Abstract: </strong>Mitchinson, CJ, Kwak, M, Succi, PJ, Benitez, B, and Bergstrom, HC. Polyphenol-rich sorghum bicolor extract enhances strength recovery after eccentric exercise. J Strength Cond Res 39(8): e951-e959, 2025-This randomized, double-blind, placebo (PL) controlled trial examined the effects of a polyphenol-rich supplement on muscular strength recovery after eccentric exercise. Twenty-nine men (mean ± SD , age = 23.1 ± 3.8 years) were randomly assigned to a high- (500 mg·d -1 ; n = 9) or low- (250 mg·d -1 ; n = 10) dose polyphenol-rich sorghum bicolor extract, or PL ( n = 10) group and completed a 17- to 18-day supplementation period, with eccentric exercise on day 14 + 1. Unilateral forearm flexion strength, muscle thickness (MT), pain pressure threshold (PPT), perceived recovery, and pain ratings were recorded before (baseline) and at 24, 48, and 72 hours after maximal eccentric exercise. Analyses included mixed-model ANCOVAs, ANOVAs, and post hoc Bonferroni corrected pairwise comparisons ( p < 0.05). After 18-25% strength losses from baseline to 24 hours, strength increased significantly from 24 to 48 hours for the high-dose group (mean difference [CI 95% ] = 5.7 N·m [2.2-9.3]; p < 0.001; d = 0.568) and from 24 to 72 hours for the low-dose group (8.3 N·m [4.4-12.2]; p < 0.001; d = 0.848), while strength remained unchanged from 24 to 72 hours for the PL group ( p = 0.101-1.000). There were no changes in MT or PPT from 24 to 72 hours. Pain ratings significantly decreased, and perceived recovery increased at 72 hours relative to 24 and 48 hours for all groups across time ( p = 0.001-0.012). Supplementation with a high- and low-dose polyphenol-rich sorghum bicolor extract increased recovery of muscular strength at faster rates than PL after eccentric exercise but had no meaningful effect on muscle swelling, perceived pain, or recovery. A polyphenol-rich supplement may enhance performance in subsequent exercise sessions and promote increased training volume.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"e951-e959"},"PeriodicalIF":3.0,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144506077","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 Knee Extension and Flexion Strength in Female Athletes at 20 and 40 Weeks After Bone-Patellar Tendon-Bone Anterior Cruciate Ligament Reconstruction.","authors":"Sofia E Klemola, Barry T Gorman, Neil Welch, Stacey M Kung","doi":"10.1519/JSC.0000000000005158","DOIUrl":"10.1519/JSC.0000000000005158","url":null,"abstract":"<p><strong>Abstract: </strong>Klemola, SE, Gorman, BT, Welch, N, and Kung, SM. Isokinetic knee extension and flexion strength in female athletes at 20 and 40 weeks after bone-patellar tendon-bone anterior cruciate ligament reconstruction. J Strength Cond Res 39(9): e1075-e1080, 2025-Despite females' higher anterior cruciate ligament (ACL) injury risk, research assessing the rehabilitation of knee extensor and flexor strength after an ACL reconstruction (ACLR) with a bone-patellar tendon-bone (BPTB) graft in female athletes is limited. The purpose of this study was to investigate the restoration of knee extension strength in female athletes after ACLR with a BPTB graft, along with knee flexion strength, limb symmetry index (LSI), and return to sport (RTS) status. Eighty-nine 16-30-year-old female athletes who underwent a BPTB ACLR were eligible for analysis. Participants completed isokinetic knee extension and flexion strength testing at 20 ± 5 (T1) and 40 ± 5 (T2) weeks post-ACLR using an isokinetic dynamometer. Changes in peak knee extension and flexion torques, and LSI values were assessed in the injured and noninjured limbs from T1 to T2. RTS status was recorded at T2. Two-way repeated measures ANOVA analyzed peak extension and flexion torques and paired t-tests analyzed LSI. Statistical significance was set at p ≤ 0.05. Compared with the injured limb, the noninjured limb demonstrated a higher peak extension torque at T1 ( p < 0.0001) and T2 ( p < 0.0001) and a higher peak knee flexion torque at T1 only ( p = 0.004). Peak knee extension ( p < 0.0001) and flexion ( p = 0.03) torque LSI were significantly higher at T2 than at T1. Despite significant improvements in knee extension and flexion strength, a deficit in the injured limb's knee extensor strength remained at 40 weeks postsurgery, which highlights the need for female athletes to prioritize strengthening the injured limb's knee extensors during rehabilitation, especially before returning to training and/or competition.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"e1075-e1080"},"PeriodicalIF":3.0,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144506075","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 Localized Muscle Mass on Sprint Mechanics During the Swing and Stance Phases of Division I Collegiate American Football Players.","authors":"Casey J Metoyer, Jonathon R Lever, Megan McGinty, Loren Landow, Robert Hunt, Jonathan D Hauenstein, Alan Huebner, Michael H Stone, John P Wagle","doi":"10.1519/JSC.0000000000005163","DOIUrl":"10.1519/JSC.0000000000005163","url":null,"abstract":"<p><strong>Abstract: </strong>Metoyer, CJ, Lever, JR, McGinty, M, Landow, L, Hunt, R, Hauenstein, JD, Huebner, A, Stone, MH, and Wagle, JP. The impact of localized muscle mass on sprint mechanics during the swing and stance phases of Division I collegiate American football players. J Strength Cond Res 39(9): 959-963, 2025-This study evaluates the impact of localized muscle volume on sprint mechanics among Division-I collegiate American football players across 3 position groups: Skills (Defensive Backs, Wide Receivers), Mids (Linebackers, Running Backs, Tight Ends), and Bigs (Offensive, Defensive Linemen). A total of 108 male athletes (age: 21.4 ± 1.9 years, BMI: 29.6 ± 4.3) were assessed. Lower extremity muscle volumes were measured using magnetic resonance imaging, and sprint kinematics were captured using an inertial measurement unit system during maximal effort sprints. Stepwise multiple linear regressions were conducted to evaluate the relationship between muscle volumes, stance, and swing times for each position group. In the Skills group, increased volumes in the vastus intermedius ( β = -0.15, p < 0.01) and sartorius ( β = -0.17, p = 0.01) were associated with reduced swing time, while those in the vastus medialis ( β = 0.18, p < 0.01) increased swing time. For stance time, the gluteus maximus ( β = -0.02, p = 0.03) was associated with reduced stance time, and the tibialis posterior ( β = 0.28, p < 0.01) increased it. In the Mids group, the biceps femoris long head ( β = -0.15, p < 0.01) was associated with reduced stance time, while the vastus medialis ( β = 0.09, p < 0.01) increased it. In the Bigs group, the rectus femoris and sartorius were associated with reduced stance time, while the tensor fasciae latae and tibialis anterior increased stance time. These findings highlight the role of localized muscle volume in influencing sprint mechanics and emphasize the potential need for position-specific physical development programs tailored to the biomechanical demands of running mechanics in American football players.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"959-963"},"PeriodicalIF":3.0,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144506079","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 Relationship Between Relative Rest and Team Performance Across Competitive Seasons in the National Football League.","authors":"Anthony G Pinzone, Yousuf Abu-Amara, Ryan W Gant, Jennifer Rivera, Emily C Tagesen, Jacob E Barkley, Adam R Jajtner","doi":"10.1519/JSC.0000000000005148","DOIUrl":"10.1519/JSC.0000000000005148","url":null,"abstract":"<p><strong>Abstract: </strong>Pinzone, AG, Abu-Amara, Y, Gant, RW, Rivera, J, Tagesen, EC, Barkley, JE, and Jajtner, AR. The relationship between relative rest and team performance across competitive seasons in the National Football League. J Strength Cond Res 39(8): 875-879, 2025-This investigation aimed to assess the relationship between relative rest index (RRI) and team performance across multiple seasons of National Football League (NFL) competition. To examine this relationship, all NFL regular season games from the 1970-71 to 2022-23 NFL seasons ( N = 12,290) were analyzed with rest intervals calculated for each team on a game-to-game basis as the number of days between current and previous games. Next, RRI was calculated as the discrepancy in rest intervals between competing teams for all games and averaged for all teams across all seasons with teams categorized by season average RRI (<-0.70; -0.7 to -0.5; -0.5 to -0.25; -0.25 to 0; 0 to 0.25; 0.25 to 0.5; 0.5 to 0.7; >0.70). Win percentage and playoff depth (lost in wild card round; lost in divisional round; lost in conference championship; lost in Super Bowl; won Super Bowl; did not make playoffs) quantified team performance. Pearson product correlations were implemented to assess the relationship between season average RRI and win percentage. One-way analyses of variance assessed differences in win percentage across RRI categories and RRI across playoff depth categories. A trivial negative correlation between RRI and win percentage across all seasons was noted. Moreover, win percentage did not differ across RRI categories, while RRI was attenuated among teams that lost in the Super Bowl and divisional round compared with teams that did not qualify for the playoffs, suggesting that RRI has no significant effect on team performance with competitive eras of NFL competition collated.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"875-879"},"PeriodicalIF":2.5,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144506080","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":"Functional Training and Mat Pilates Are Effective in Improving Cardiorespiratory Capacity and Strength in People With Parkinson's Disease: A Randomized Clinical Trial With Follow-up.","authors":"Jéssica Amaro Moratelli, Clynton Lourenço Corrêa, Anelise Sonza, Adriana Coutinho de Azevedo Guimarães","doi":"10.1519/JSC.0000000000005162","DOIUrl":"10.1519/JSC.0000000000005162","url":null,"abstract":"<p><strong>Abstract: </strong>Moratelli, JA, Corrêa, CL, Sonza, A, and Guimarães, ACdA. Functional training and mat pilates are effective in improving cardiorespiratory capacity and strength in people with Parkinson's disease: a randomized clinical trial with follow-up. J Strength Cond Res 39(9): e1119-e1128, 2025-The objective of this study was to analyze the effects of 2 12-week interventions with functional training and Mat Pilates on cardiorespiratory capacity, lower limb strength, and handgrip strength in people with Parkinson's disease, both in the short term and in the long term. Randomized clinical trial with people with Parkinson's randomized into 3 groups: functional training ( n = 12), Mat Pilates ( n = 11), and control group ( n = 12), as well as 11 healthy individuals matched by sex and age, constituting the healthy reference group. The exercise groups received 2 60-minute sessions per week for 12 weeks. Assessments were conducted before and after the interventions with all participants and included submaximal functional capacity, handgrip strength, and lower limb muscle strength. Significance level p ≤ 0.05. In the intragroup comparison of functional training and Mat Pilates, the results indicated significant improvements in cardiorespiratory capacity and lower limb muscle strength in both the short and long terms ( p < 0.001), as well as short-term improvement in right handgrip strength ( p = 0.003). In the control group, a deterioration in right leg extension strength was observed in the short term and at the follow-up ( p = 0.038). The study suggests that 12 weeks of functional training and Mat Pilates are effective in improving cardiorespiratory fitness, lower limb muscle strength, and right-hand handgrip strength in individuals with Parkinson's disease. These benefits are particularly relevant as they may contribute to maintaining autonomy, mobility, and quality of life in this population, reinforcing the importance of physical exercise as a complementary treatment for Parkinson's disease.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"e1119-e1128"},"PeriodicalIF":3.0,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144506062","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 Court Orientation and Bout-Ending Mechanism on the External and Internal Loads of Female Basketball Players During Small-Sided Games.","authors":"Alejandro Rodríguez-Fernández, Enrique Flórez-Gil, Aaron Scanlan, Alejandro Vaquera","doi":"10.1519/JSC.0000000000005174","DOIUrl":"10.1519/JSC.0000000000005174","url":null,"abstract":"<p><strong>Abstract: </strong>Rodríguez-Fernández, A, Flórez-Gil, E, Scanlan, A, and Vaquera, A. The impact of court orientation and bout-ending mechanism on the external and internal loads of female basketball players during small-sided games. J Strength Cond Res 39(9): e1081-e1090, 2025-The aims were to examine the impact of court orientation and bout-ending mechanism on external and internal loads during small-sided basketball games (SSG) in female players and examine performance-related fatigue associated with SSG formats. Twelve female basketball players participated in 4 SSG formats over a 4-week period. External (measured using local positioning system) and internal (measured using heart rate) load variables were collected. Countermovement jump and 20-m sprint were assessed pre and post each SSG. Each SSG involved 3vs3 and 3 bouts. Small-sided games formats included: (a) fixed time (3 minutes) in half-court orientation (15 × 14 m with 1 basket); (b) fixed time (3 minutes) in stretched-court orientation (7.5 × 28 m with 2 baskets); (c) fixed point (first to 5 points) in half-court orientation; and (d) fixed point (first to 5 points) in stretched-court orientation. Stretched-court SSG formats resulted in significantly greater external loads ( p < 0.01, effect size [ES] = 1.89-4.42). Countermovement jump height increased ( p < 0.05; ES = 0.40-0.43) across all SSG except the stretched-court fixed-point format, with 20-m sprint time unaffected across all SSG ( p ≥ 0.05; ES = 0.11-0.27). Stretched-court 3vs3 SSG formats elicit greater external loads than half-court, whereas fixed-time and fixed-point bout-ending formats yield comparable demands.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"e1081-e1090"},"PeriodicalIF":3.0,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144266492","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":"Specificity in Change of Direction Training: Impact on Performance Across Different Tests.","authors":"Michael Keiner, Konstantin Warneke, Josua Skratek, Björn Kadlubowski, Konstantin Beinert, Andreas Wittke, Klaus Wirth","doi":"10.1519/JSC.0000000000005171","DOIUrl":"10.1519/JSC.0000000000005171","url":null,"abstract":"<p><strong>Abstract: </strong>Keiner, M, Warneke, K, Skratek, J, Kadlubowski, B, Beinert, K, Wittke, A, and Wirth, K. Specificity in change of direction training: Impact on performance across different tests. J Strength Cond Res 39(9): 945-951, 2025-This study aimed to evaluate the specificity of change of direction (COD) training by investigating whether a targeted training protocol would yield superior adaptations when test and training exercises align, compared with standard soccer practice. Seventy-seven elite youth soccer players participated in a 4-arm, 4-week randomized intervention, with subjects completing 3 additional COD training sessions per week alongside their regular soccer training depending on their randomized group assignment. The training focused on either the 505, the Triangle, or the Curved Sprint COD tasks, while the control group did not receive any additional intervention. The results showed that COD training with cuts over 120° (Triangle and 505 intervention groups) led to significant (<0.05) performance improvements across all COD tests (Triangle, 505, and Curved Sprint). By contrast, the Curved Sprint intervention group improved only in the Curved Sprint test, and the control group showed no significant ( p > 0.05) gains. However, sport-specific CODs vary significantly based on tactical and technical demands, making their precise definition and consequently the standardization of training challenging. Nonetheless, this study demonstrates that tailoring COD training to the specific movement requirements of the COD tests can effectively maximize performance improvements.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"945-951"},"PeriodicalIF":3.0,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144258228","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":"Twice a Day Lacrosse Training in Temperate Conditions Results in a Negative 24-Hour Sodium Balance in Male and Female University Lacrosse Players.","authors":"Heather Z Macrae, Kirsty M Reynolds, Thomas G Cable, Asya Barutcu, Emily J Hansell, Stephen A Mears, Katharine L Midwood, Callum Mould, Mark P Funnell, Vicky L Goosey-Tolfrey, Lewis J James","doi":"10.1519/JSC.0000000000005164","DOIUrl":"10.1519/JSC.0000000000005164","url":null,"abstract":"<p><strong>Abstract: </strong>Macrae, HZ, Reynolds, KM, Cable, TG, Barutcu, A, Hansell, EJ, Mears, SA, Midwood, KL, Mould, C, Funnell, MP, Goosey-Tolfrey, VL, and James, LJ. Twice a day lacrosse training in temperate conditions results in a negative 24-hour sodium balance in male and female university lacrosse players. J Strength Cond Res 39(9): e1091-e1098, 2025-This study measured 24-hour fluid and sodium balance in 27 university lacrosse players (13 males, 14 females; 21 ± 1 years). For 24 hours, participants maintained their usual fluid and food intake, completed a weighed food diary, and collected all urine produced. Participants completed 2 bouts of 1.5 hours (males) or 2 hours (females) lacrosse training (16.0 ± 3.9°C, 62.3 ± 11.7% relative humidity) separated by 2-2.5 hours rest. Nude body mass was measured at baseline (0 hour), 24 hours later, before and after training, and corrected for food/fluid consumed and urine/feces produced during training to determine sweat losses. A sweat patch was applied (scapula) and analyzed for sweat sodium concentration. Data are mean ± standard deviation or median (Q1-Q3), p < 0.05. Sodium balance at 24 hours was negative for both male (-0.76 ± 1.31 g) and female (-0.47 ± 0.70 g) players but was not different between sexes ( p = 0.350). Body mass at 0 hour and 24 hours was not different for male (79.99 ± 10.02 kg vs 79.69 ± 10.15 kg) or female (65.68 ± 10.17 kg vs 65.82 ± 10.21 kg; both p > 0.05) players. Sweat rates were relatively low and not different between male (0.39 ± 0.23 L/h) and female (0.33 ± 0.18 L/h; p = 0.286) players. There was no difference in sweat sodium concentration (male players: 27 (23-28) mmol/L; female players: 27 (23-31) mmol/L; p = 0.786). Ad libitum drinking, combined with low sweat rates, generally prevented dehydration accruing to a level that might impair performance. Sodium balance deficit was small (∼0.61 g) but may require investigation to understand whether daily deficits accumulate.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"e1091-e1098"},"PeriodicalIF":3.0,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144266503","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}