Journal of Strength and Conditioning Research最新文献

{"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":"https://doi.org/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 XX(X): 000-000, 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":""},"PeriodicalIF":2.5,"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":"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":"https://doi.org/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 XX(X): 000-000, 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":""},"PeriodicalIF":2.5,"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":"Reference Standards for Vertical Jump Power and Handgrip Strength for Screening the Risk of Low Bone and Muscle Mass for Age in Youth.","authors":"Fátima Baptista, Rafael Luiz de Marco, Vera Zymbal, Kathleen F Janz","doi":"10.1519/JSC.0000000000005130","DOIUrl":"https://doi.org/10.1519/JSC.0000000000005130","url":null,"abstract":"<p><strong>Abstract: </strong>Baptista, F, de Marco, RL, Zymbal, V, and Janz, KF. Reference standards for vertical jump power and handgrip strength for screening the risk of low bone and muscle mass for age in youth. J Strength Cond Res XX(X): 000-000, 2025-This study examined the predictive validity of vertical jump power and handgrip strength to discriminate at-risk youth for low muscle mass and bone mass for age. The sample consisted of 529 subjects of ages 10-18 years. Handgrip strength and vertical jump power were assessed using a hand dynamometer and a countermovement jump performed on a force platform. Dual-energy X-ray absorptiometry was used to assess lean body mass normalized for body height (kg·m-2) and bone mineral density (g·cm-2) of the whole body less head. These variables were used to determine the risk of low bone and muscle mass, defined by a Z-score ≤ -1.0 for both variables. All variables were standardized by the lambda-mu-sigma method according to sex and age group, using the sample as a reference. By sex, the analysis included the area under the curve (AUC), sensitivity (Se), and specificity (Sp). The ability to discriminate the risk of low bone and muscle mass through the assessment of musculoskeletal fitness was good to exceptional for vertical jump power (AUCs ≥0.88, Se and Sp = 78-91%) and acceptable to good for handgrip strength (AUCs = 0.75-0.88, Se and Sp = 68-73%). Risk Z-scores for musculoskeletal fitness ranged from -0.5 to -0.8, depending on the test and sex. Handgrip strength and especially vertical jump power can be used to screen the risk of pediatric low bone and muscle mass. Slight decreases in musculoskeletal fitness can be an inexpensive and noninvasive indicator of muscle and bone health.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144258227","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 XX(X): 000-000, 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":""},"PeriodicalIF":2.5,"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}

{"title":"Agility and Not Change of Direction Speed Discriminates Competitive Level in Young Soccer Players.","authors":"Glauber B Menezes, Ricardo S Oliveira, Jon L Oliver, Rhodri S Lloyd, Arnaldo L Mortatti","doi":"10.1519/JSC.0000000000005172","DOIUrl":"https://doi.org/10.1519/JSC.0000000000005172","url":null,"abstract":"<p><strong>Abstract: </strong>Menezes, GB, Oliveira, RS, Oliver, JL, Lloyd, RS, and Mortatti, AL. Agility and not change of direction speed discriminates competitive level in young soccer players. J Strength Cond Res XX(X): 000-000, 2025-This study aimed to examine the discriminant ability of agility and change of direction speed (CODS) among young soccer players. Eighty-seven male soccer players (U-15 age group) were analyzed and grouped based on competitive level as nonelite, subelite, and elite players. Anthropometry, maturity offset, agility (perception-decision time, and movement response time), and CODS were assessed. Linear discriminant analysis (LDA) was applied to obtain the standardized coefficients of each variable in the model and the accuracy of the model comparing the predicted with the true group. Aiming to describe the discriminant ability of CODS and agility, all LDA models also included subjects age, maturity offset, and training age. Standard discriminant function (SDF) revealed that CODS (SDF = -0.012) or perception-decision (SDF = -0.380) time has a reduced discriminatory ability compared with age and maturity offset. When considering all variables, movement response time (SDF = -0.726) and maturity offset (SDF = 0.595) contributed the most to the discriminant ability of the models (75% accuracy). Moreover, movement response time correctly classified elite (accuracy >84%) compared with subelite and nonelite players. Our results indicate that agility tests with specific stimuli are better than CODS tests at distinguishing young soccer players of different competitive levels, even when considering the effects of age, maturity status, and training age. In addition, the movement response time emerges as the primary factor influencing agility performance in young athletes. Monitoring these qualities may help coaches in the talent identification and development program.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144258224","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":"Effects of Squat Training, Jump Training, and Their Combination on Jump and Sprint Performance of Team Sports Athletes: A Systematic Review With Meta-Analysis.","authors":"Paul Ulloa-Sánchez, Rohit K Thapa, Jessenia Hernández-Elizondo, Andrew Sortwell, Rodrigo Ramirez-Campillo","doi":"10.1519/JSC.0000000000005161","DOIUrl":"10.1519/JSC.0000000000005161","url":null,"abstract":"","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144266488","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":"Reliability of Time Spent Near V̇o2max During 2 Cycling Interval Training Sessions: The Effect of V̇o2max Criteria.","authors":"João A G Raimundo, Artur F Tramontin, Eduardo C Martins, Fernando K Borszcz, Tiago Turnes, Rafael A de Aguiar, Fabrizio Caputo","doi":"10.1519/JSC.0000000000005154","DOIUrl":"https://doi.org/10.1519/JSC.0000000000005154","url":null,"abstract":"<p><strong>Abstract: </strong>Raimundo, JAG, Tramontin, AF, Martins, EC, Borszcz, FK, Turnes, T, de Aguiar, RA, and Caputo, F. Reliability of time spent near V̇o2max during 2 cycling interval training sessions: the effect of V̇o2max criteria. J Strength Cond Res XX(X): 000-000, 2025-This study aimed to determine the reliability of the time spent near V̇o2max (tV̇o2max) during 2 work-matched cycling interval trainings and to compare tV̇o2max reliability using different V̇o2max criteria. Fifteen healthy males participated in this cross-sectional and crossover study. The participants performed on different days, an incremental ramp test followed by a V̇o2max verification test, and a test-retest model to analyze tV̇o2max during 2 distinct work-matched interval training sessions. The interval training protocols comprised 5 × 2-minute efforts with 1-minute recovery (HIIT2min:1min) or 10 × 1-minute efforts with 30-second recovery (HIIT1min:30s) at 85% of the incremental peak power output, both followed by a V̇o2max verification test. Times sustained above 90 and 95% (t95V̇o2max) of V̇o2max were analyzed and were compared based on 3 different criteria: (a) V̇o2max from incremental and verification test (V̇o2maxINC-VER); (b) V̇o2max from the verification test on the training day (V̇o2maxDAY); and (c) mean V̇o2max from V̇o2maxINC-VER and V̇o2maxDAY. There were no significant differences in test-retest tV̇o2max; the only exception was t95V̇o2max during HIIT1min:30s assessed by V̇o2maxINC-VER. The typical error of measurement and coefficient of variation ranged from 28 to 61 seconds and 19%-35% for HIIT2min:1min, and from 21 to 66 seconds and 36%-72% for HIIT1min:30s. V̇o2maxINC-VER reduced tV̇o2max coefficient of variation compared with V̇o2maxDAY for HIIT2min:1min, but not for HIIT1min:30s. Despite similar test-retest, tV̇o2max exhibited low reliability, with no improvement when a V̇o2max verification test was included on the training day.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144266490","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":"Barbell Trajectory Patterns and Successful Power Clean Execution: Insights From a Bivariate Functional Principal Component Analysis.","authors":"Tsuyoshi Nagatani, Shayne Vial, Kristina L Kendall, Paul Comfort, G Gregory Haff","doi":"10.1519/JSC.0000000000005178","DOIUrl":"10.1519/JSC.0000000000005178","url":null,"abstract":"<p><strong>Abstract: </strong>Nagatani, T, Vial, S, Kendall, KL, Comfort, P, and Haff, GG. Barbell trajectory patterns and successful power clean execution: Insights from a bivariate functional principal component analysis. J Strength Cond Res XX(X): 000-000, 2025-Coaches frequently analyze the bar path during weightlifting movements using graphical representations. Although this analysis method helps understand the biomechanics of weightlifting technique, researchers have not thoroughly examined how specific bar path patterns relate to successful power clean performance. Therefore, 25 strength-power athletes (height: 1.78 ± 0.08 m, body mass: 88.0 ± 15.0 kg, age: 27.2 ± 4.0 years, relative 1 repetition maximum [1RM] of power clean: 1.22 ± 0.16 kg·kg -1 , power clean experience range: 4.2 ± 2.1 years) were recruited from local weightlifting clubs to determine the barbell trajectory patterns that relate to successful power clean performance. All subjects completed a 1RM power clean test where barbell trajectory data from the heaviest successful lift and the heaviest unsuccessful lift were analyzed. A bivariate functional principal component analysis was applied to the extracted barbell trajectory data to determine whether these data could distinguish between successful and unsuccessful maximal power clean attempts. Successful power clean attempts were characterized by a higher vertical barbell displacement at the power position and a greater peak vertical velocity during the second pull, resulting in overall higher maximum vertical barbell displacement compared with unsuccessful attempts. Therefore, coaches should reinforce techniques that ensure that the barbell reaches a high point at the initiation of the second pull (i.e., power position). This can be related to achieving an overall high vertical barbell displacement at the end of the second pull and during the catch, which may enable athletes to lift heavier loads during maximal testing and daily training sessions.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144266487","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 Vertical Jump Height, Hamstrings Flexibility and Strength on Maximal Sprint Speed in Division I Track and Field Athletes.","authors":"Kevin P Doyle, Corry M Brinken, Christina N Capito, Emily T Karp, Marisa N Mariani, Sara Meza, Jason K Grimes","doi":"10.1519/JSC.0000000000005175","DOIUrl":"10.1519/JSC.0000000000005175","url":null,"abstract":"<p><strong>Abstract: </strong>Doyle, KP, Brinken, CM, Capito, CN, Karp, ET, Mariani, MN, Meza, S, and Grimes, JK. The impact of vertical jump height and hamstrings flexibility and strength on maximal sprint speed in Division I track and field athletes. J Strength Cond Res XX(X): 000-000, 2025-The purpose of this study was to examine the relationship between hamstrings flexibility, eccentric strength, and vertical jump height with maximal sprint speed (MSS) in collegiate Division 1 track and field athletes. The impact of previous hamstrings injury was also investigated in an exploratory secondary analysis. The 90/90 active knee extension test was used to examine flexibility of the hamstrings. Vertical jump height was assessed as an indicator of lower extremity power. Eccentric peak torque of the hamstrings was assessed with isokinetic dynamometry at 60°/s -1 . Maximal sprint speed was measured over a 60-meter distance by taking the fastest 10-meter flying split using electronic timing gates. The level of significance was set at p < 0.05. Vertical jump height had a significant strong positive correlation ( r = 0.74; p < 0.001) with MSS. Hamstrings flexibility on the right had a significant weak negative correlation ( r = -0.37; p = 0.03) with MSS. No significant correlations were found between hamstrings flexibility on the left ( r = -0.20; p = 0.26) or eccentric normalized peak torque (right: r = 0.15; p = 0.40; left: r = 0.27; p = 0.13) and MSS. Vertical jump height demonstrated the strongest correlation with MSS. When comparing those with and without previous hamstrings injury, vertical jump height (mean 67.5 vs. 55.1 cm; p = 0.062) may have clinical importance and should be examined in a larger sample with previous hamstring injury. Understanding how the hamstrings adapt to sprint-specific training will contribute to the design and implementation of training programs in track and field athletes to improve performance.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144266493","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":"A Novel Method for Assessing Load-Velocity Profiles With a Motorized Resistance Device in the Sit-to-Stand Test in Older Adults.","authors":"Daniel Jiménez-Lupión, Ignacio Chirosa-Ríos, Rodrigo Lizama-Pérez, Luis Chirosa-Ríos, Daniel Jerez-Mayorga","doi":"10.1519/JSC.0000000000005173","DOIUrl":"https://doi.org/10.1519/JSC.0000000000005173","url":null,"abstract":"<p><strong>Abstract: </strong>Jiménez-Lupión, D, Chirosa-Ríos, I, Lizama-Pérez, R, Chirosa-Ríos, L, and Jerez-Mayorga, D. A novel method for assessing load-velocity profiles with a motorized resistance device in the sit-to-stand test in older adults. J Strength Cond Res XX(X): 000-000, 2025-The load-velocity (L-V) relationship correlates external load and lifting velocity, and the 2-point method for determining this relationship has become a reliable way to assess muscle mechanical capacities. This assessment could prove highly valuable in geriatrics and aging research because it helps identify early declines in muscle strength and power. Functional Electromechanical Dynamometry (FEMD) enables load, velocity, and power measurements during multijoint tasks, like the sit-to-stand (STS) test, facilitating comprehensive muscle function assessment in older adults. This study aimed to evaluate the test-retest reliability and concurrent validity of the 2-point method for determining the L-V relationship using FEMD during loaded STS tasks. Thirty healthy subjects (23 women, 7 men; mean age 61 ± 9.33 years; mean body mass 70.5 ± 14.7 kg; mean height 1.59 ± 0.07 m) participated. They performed unloaded and loaded 5-STS tasks with FEMD. Mean velocities from all loads were used to calculate individual L-V relationships. The absolute reliability demonstrated acceptable repeatability for L0 (i.e., load at zero velocity) (coefficient of variation [CV]: 9.97%; intraclass correlation coefficient [ICC]: 0.94), V0 (i.e., velocity at zero load) (CV: 5.70%; ICC: 0.95), and Aline (i.e., the area under the L-V relationship line) (CV: 7.60%; ICC: 0.98) with a CV < 10% in all cases. Regarding the concurrent validity of Aline variable with respect to mean mechanical power, a high correlation was observed (r = 0.82; p = < 0.001). This study confirms the reliability and validity of the 2-point method using FEMD for assessing L-V relationships and muscle power during 5-STS in older adults.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144266486","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}