Journal of Strength and Conditioning Research最新文献

{"title":"Improved Quadriceps Torque Production With Optimized Biofeedback in Patients After Anterior Cruciate Ligament Reconstruction.","authors":"Jennifer A Hogg, Nathan B Barger, Jeremy R Bruce, Charles C White, Gregory D Myer, Jed A Diekfuss","doi":"10.1519/JSC.0000000000004883","DOIUrl":"10.1519/JSC.0000000000004883","url":null,"abstract":"","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"1974-1980"},"PeriodicalIF":2.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141792760","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 the Anaerobic Speed Reserve and Acute Responses to High-Intensity Interval Training in Female Soccer Players.","authors":"Greg L Aspin, Michael K Graham, John D Franklin, Kirsty M Hicks, Jonathan M Taylor","doi":"10.1519/JSC.0000000000004900","DOIUrl":"10.1519/JSC.0000000000004900","url":null,"abstract":"<p><strong>Abstract: </strong>Aspin, GL, Graham, M, Franklin, J, Hicks, KM, and Taylor, JM. The relationship between the anaerobic speed reserve and acute responses to high-intensity interval training in female soccer players. J Strength Cond Res 38(11): 1911-1916, 2024-The anaerobic speed reserve (ASR) is a popular method of profiling soccer players, often used to individualize training prescription. This study explored the reliability of ASR profiling, and the relationship between the ASR and acute physiological responses to high-intensity interval training (HIIT). Acute physiological responses to different HIIT types were also compared. Thirteen subelite female soccer players aged 20.2 ± 4.6 years completed 6 exercise sessions. In sessions 1-2, players completed a 40-m sprint to assess maximal sprint speed (MSS) and 1600-m time-trial to estimate maximal aerobic speed (MAS), which were used to calculate ASR and assess test-retest reliability. In sessions 3-6, players completed 4 HIIT sessions (repeated-sprint training, sprint interval training, long intervals, and short intervals HIIT). Intensities for long and short intervals HIIT were individualized according to MAS. Ratings of perceived exertion (RPE), heart rate (HR), and postsession blood lactates were recorded throughout. Relationships between the ASR and acute responses to HIIT, and between HIIT session comparisons in outcome measures were assessed. Anaerobic speed reserve (coefficient of variation ± 95% confidence limits; 3.1 ± 1.5%), MAS (1.8 ± 1.3%), and MSS (0.8 ± 0.6%) indicated acceptable reliability. Moderate correlations between ASR and RPE ( r = 0.33), postsession blood lactate ( r = 0.34), and HR ( r = 0.37) were observed during long intervals HIIT. A strong correlation was observed between ASR and RPE during SIT ( r = 0.50). Sprint interval training elicited higher RPE's and postsession blood lactate's than other HIIT sessions. Anaerobic speed reserve has good reliability and may influence acute physiological responses to HIIT in female soccer players.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"1911-1916"},"PeriodicalIF":2.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141627059","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":"Validity and Reliability of the Power Slap Board as an Application to Measure Upper Body Vertical Pulling Power for Female Water Polo Players.","authors":"Charmaine Lim, Jericho Wee, Melissa Lee, Sean Lim, Shina Leow","doi":"10.1519/JSC.0000000000004891","DOIUrl":"10.1519/JSC.0000000000004891","url":null,"abstract":"<p><strong>Abstract: </strong>Lim, C, Wee, J, Lee, M, Lim, S, and Leow, S. Validity and reliability of the power slap board as an application to measure upper body vertical pulling power for female water polo players. J Strength Cond Res 38(11): e670-e677, 2024-This study examined the validity and reliability of the power slap test (PS) as an assessment for upper body pulling power to predict water polo functional performance and competitive experience of female water polo players. Seventeen female water polo players from the national and development squads were recruited. Subjects completed test-retest sessions of PS testing and 1 session of functional performance tests for the 15-m arms-only sprint (15 mAOS) and the 5-m maximum shooting velocity (5 mMSV). All PS, 15 mAOS and 5 mMSV results were compared for predictability. Power slap scores demonstrated high reliability for left PS (intraclass correlations [ICC]: 0.96, 90% confidence interval [CI]: 0.91-0.98), right PS (ICC: 0.96, 90% CI: 0.90-0.98), left and right center of mass (COM) displacement (ICC: 0.98, 90% CI: 0.96-0.99; ICC: 0.95, 90% CI: 0.88-0.98), and summed PS (ICC: 0.96, 90% CI: 0.92-0.99). All absolute PS scores and left COM displacement (COM disp L) demonstrated large correlations with the 15 mAOS times ( r = -0.542 to -0.52, r2 = 0.27-0.29, p < 0.05). No performance parameters of the PS were correlated with the 5 mMSV performance ( p > 0.05). This study validates the reliability of the PS as a dryland assessment tool for upper body pulling power. Only absolute PS scores and COM disp were validated as weak predictors of the arms-only sprint times over 15 m. Its predictive power significantly improved when considered in combination with shooting performance. All absolute and normalized kinetic and kinematic PS parameters did not predict functional performance and competitive experience.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"e670-e677"},"PeriodicalIF":2.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11498836/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141627060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acute Effects of High-Intensity Resistance Exercise on Recognition of Relational Memory, Lactate, and Serum and Plasma Brain-Derived Neurotrophic Factor.","authors":"Nicholas W Baumgartner, Michael D Belbis, Christopher Kargl, Michael J Holmes, Timothy P Gavin, Daniel M Hirai, Shih-Chun Kao","doi":"10.1519/JSC.0000000000004851","DOIUrl":"10.1519/JSC.0000000000004851","url":null,"abstract":"<p><strong>Abstract: </strong>Baumgartner, NW, Belbis, MD, Kargl, C, Holmes, MJ, Gavin, TP, Hirai, DM, and Kao, S-C. Acute effects of high-intensity resistance exercise on recognition of relational memory, lactate, and serum and plasma brain-derived neurotrophic factor. J Strength Cond Res 38(11): 1867-1878, 2024-Acute aerobic exercise improves memory, but this phenomenon is understudied in response to resistance exercise (RE) despite evidence that RE-induced increases in lactate and brain-derived neurotrophic factor (BDNF) play mechanistic roles in memory performance. To determine the acute effect of RE on lactate, BDNF, and their associations with object and relational memory, blood lactate, and serum and plasma BDNF were taken from 36 adults (average age 23.64 ± 3.89 years; 18 woman) before and immediately after 42 minutes of high-intensity RE and a rest condition on counterbalanced days. Subjects then immediately studied a series of paired objects and completed object and relational recognition tasks. Results revealed a condition by trial interaction, previously studied objects were remembered less accurately following RE ( d = 0.66) but recognition occurred faster ( d = 0.28), indicating a speed-accuracy tradeoff following RE. There was no effect of either intervention on relational recognition performance. Lactate ( d = 3.68) and serum BDNF ( d = 0.74) increased following RE, whereas there was no time-related change in lactate and serum BDNF following rest. However, changes in lactate and BDNF did not predict any measures of object ( rs < 0.25, p s > 0.16) or relation recognition ( rs < 0.28, p s > 0.13). Collectively, these findings suggest that acute high-intensity RE selectively improves the processing speed of recognizing objects at the cost of less accurate recognition of previously studied objects. Furthermore, changes in object and relational memory performance are unlikely driven by acute increases in lactate or BDNF following high-intensity RE.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"1867-1878"},"PeriodicalIF":2.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141792691","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":"Comparison of the Effects of a Roller Massager Intervention on the Rectus Femoris Between Lengthened and Slack Positions.","authors":"Kazuki Kasahara, Andreas Konrad, Yuta Murakami, Ewan Thomas, Masatoshi Nakamura","doi":"10.1519/JSC.0000000000004895","DOIUrl":"10.1519/JSC.0000000000004895","url":null,"abstract":"<p><strong>Abstract: </strong>Kasahara, K, Konrad, A, Murakami, Y, Thomas, E, and Nakamura, M. Comparison of the effects of a roller massager intervention on the rectus femoris between lengthened and slack positions. J Strength Cond Res 38(11): 1879-1884, 2024-A roller massager (RM) is a type of foam rolling device, which previous studies have shown to be effective for acutely decreasing tissue hardness and increasing range of motion (ROM). However, these effects may differ with the RM intervention position (i.e., knee flexion or knee extension). Therefore, this study aimed to compare the acute effects of an RM intervention on the rectus femoris (RF) in the knee flexed and extended positions. The subjects were 14 healthy male college students (age, 22.6 ± 0.8 years). The RF of the dominant leg was tested. Three conditions were compared: a control condition with no intervention (CON), an RM intervention in knee extension (i.e., RM_extension), and a RM intervention in knee flexion (i.e., RM_flexion). The measurements were tissue hardness in the proximal (TH_pro), middle (TH_mid), and distal (TH_dis) portions of the RF, knee flexion ROM, pain pressure threshold (PPT), maximal voluntary isometric contraction (MVC-ISO) torque, and maximal voluntary concentric contraction (MVC-CON) torque in the RF before and immediately after the intervention. There were significant interaction effects of TH_mid and knee flexion ROM. Both RM_extension and RM_flexion conditions showed a significant ( p < 0.01) decrease in TH_mid and an increase in knee flexion ROM, but there were no significant differences between conditions. There was a main effect for TH_pro and PPT ( p < 0.05) but no significant interaction effect or main effect for TH_dis, MVC-ISO torque, and MVC-CON torque. The results showed that the RM intervention can effectively decrease tissue hardness and increase ROM, regardless of limb position (i.e., knee extension or flexion).</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"1879-1884"},"PeriodicalIF":2.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141627053","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":"High-Intensity Running During International Male Field Hockey Involves Frequent Changes of Direction and Repeated Accelerations but Seldom Reaches Sprint Velocities.","authors":"Paul S R Goods, Brendyn Appleby, Brendan R Scott, Peter Peeling, Brook Galna","doi":"10.1519/JSC.0000000000004880","DOIUrl":"10.1519/JSC.0000000000004880","url":null,"abstract":"<p><strong>Abstract: </strong>Goods, PS, Appleby, B, Scott, BR, Peeling, P, and Galna, B. High-intensity running during international male field hockey involves frequent changes of direction and repeated accelerations but seldom reaches sprint velocities. J Strength Cond Res 38(11): 1933-1940, 2024-The aim of this investigation was to quantify the characteristics of high-intensity running in international male field hockey. Player movement data were collected through wearable player tracking devices across 3 tournaments (17 matches) from 27 members of the Australian male field hockey team (totaling 266 player matches). Active duration (minute), high-intensity efforts (>2.5 m·s -2 for >1 second), repeated high-intensity efforts (≥3 efforts with ≤45-second recovery between efforts), and sprints (>7 m·s -1 ) were extracted and aggregated for each player match. The duration, distance, mean and peak speed, mean change of direction and straightness for each high-intensity effort, and peak deceleration at the conclusion of each effort were calculated. Mixed-effects models were used to estimate the mean for each outcome (fixed effect), with random intercepts modeled for player and match. On average, players completed 42.2 high-intensity efforts and 2.1 sprints per match. High-intensity efforts were short (3.61 seconds, 12.9 m), failed to reach high velocities (average peak velocity: 4.8 m·s -1 ), and involved frequent changes of direction (56% of efforts were not straight). There were 4.7 bouts of repeated high-intensity efforts per player, per match (comprising 3.8 efforts, with 3.53 seconds per effort separated by 16.2-second recovery). Last, we also found that 29% of high-intensity efforts involved a high-speed deceleration (>3.5 m·s -2 ), and these occurred frequently when in conjunction with a >45° (86%) or >90° (89%) change of direction. We recommend practitioners focus on developing players' ability to repeatedly accelerate, decelerate, and change direction over short distances and adopt testing and monitoring programs that assess these qualities.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"1933-1940"},"PeriodicalIF":2.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141627056","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":"Intramuscular Hamstring Stiffness Affects Anatomically Modeled Localized Muscle Strain During Passive Hip Flexion.","authors":"Carlos O Rehbein, Jacob M McDougle, Luis E Peñailillo, Jacob E Earp","doi":"10.1519/JSC.0000000000004898","DOIUrl":"10.1519/JSC.0000000000004898","url":null,"abstract":"<p><strong>Abstract: </strong>Rehbein, CO, McDougle, JM, Peñailillo, L, and Earp, JE. Intramuscular hamstring stiffness affects anatomically modeled localized muscle strain during passive hip flexion. J Strength Cond Res 38(11): 1860-1866, 2024-Hamstring strain injuries occur when localized tissue strain capacity is exceeded. Localized strain may be affected by intramuscular variation in stiffness, but research in this area is lacking. The purpose of this study was to determine the effects of intramuscular hamstring stiffness on localized muscle strain during passive hip flexion. Twenty-eight (age 25.0 ± 4.9 years) healthy women ( n = 15) and men ( n = 13) had biceps femoris, semitendinosus, and semimembranosus stiffness measured proximally, medially, and distally during passive hip flexion and extension using shear-wave elastography. Anthropometric and stiffness measurements were entered into an anatomical model of equivalent springs to estimate localized tissue strain and differentiate between the relative contribution to passive strain from each muscular region. In shortened and stretched positions, stiffness was lowest proximally for all muscles (Cohen's d = 0.66-0.79, p < 0.001). In addition, relative strain contribution was greater proximally (37.5-39.4%) compared with middle (31.74-32.2%) or distal (28.6-30.3%) regions ( p < 0.001), with proximal contribution to strain increasing with greater hip flexion. Our results suggest that intramuscular variations in passive hamstring stiffness contribute to inhomogeneous strain throughout the muscle during passive hip flexion. Given the prevalence of proximal stretch-pattern strain injuries, variation in intramuscular stiffness may contribute to risk for such injuries.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":"1860-1866"},"PeriodicalIF":2.5,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141792761","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 a Short-Term Detraining Period on the Physical Fitness in Elite Youth Soccer Players: A Comparison Between Chronological Age Groups.","authors":"Alexis Padrón-Cabo, Miguel Lorenzo-Martínez, Vicente De Dios-Álvarez, Ezequiel Rey, David Solleiro-Durán","doi":"10.1519/JSC.0000000000004975","DOIUrl":"https://doi.org/10.1519/JSC.0000000000004975","url":null,"abstract":"<p><strong>Abstract: </strong>Padrón-Cabo, A, Lorenzo-Martínez, M, De Dios-Álvarez, V, Rey, E, and Solleiro-Durán, D. Effects of a short-term detraining period on the physical fitness in elite youth soccer players: a comparison between chronological age groups. J Strength Cond Res XX(X): 000-000, 2024-The aim of this study was to examine the effects of a 2-week in-season training cessation on neuromuscular and endurance performance in 2 different age groups of elite youth soccer players. A total of 30 players belonging to the under-15 (U15, n = 17) and under-17 (U17, n = 13) age groups of a Spanish professional soccer academy participated in the study. The following tests were assessed before and after the training cessation period: squat jump (SJ), countermovement jump (CMJ), 20-m sprint with 5-m and 10-m split times, modified 505 change of direction, and 30-15 Intermittent Fitness Test (30-15 IFT). The results showed significant and similar performance impairments between the 2 age groups in SJ (p = 0.020), CMJ (p = 0.044), 20-m sprint (p < 0.001), and 30-15 IFT (p < 0.001). The U17 players evidenced greater impairment than the U15 players in 5-m (p = 0.006) and 10-m (p = 0.002) sprint performance. However, there was no significant change (p = 0.070) in the players' change of direction performance. These findings provide valuable information for strength and conditioning coaches, suggesting the need for targeted interventions to mitigate the effects of detraining on neuromuscular and endurance performance during short-term in-season training cessation periods in elite youth soccer players. Special attention should be paid to maintaining sprint performance during short-term detraining periods in U17 players.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546118","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 Light Versus Very Heavy Resisted Sprint Training on Multidirectional Speed in Semi-professional Soccer Players.","authors":"Andrés Baena-Raya, Juan Robles-Ruiz, Alejandro Pérez-Castilla, Fernando Pareja-Blanco, Manuel A Rodríguez-Pérez","doi":"10.1519/JSC.0000000000004993","DOIUrl":"https://doi.org/10.1519/JSC.0000000000004993","url":null,"abstract":"<p><strong>Abstract: </strong>Baena-Raya, A, Robles-Ruiz, J, Pérez-Castilla, A, Pareja-Blanco, F, and Rodríguez-Pérez, MA. Effects of light versus very heavy resisted sprint training on multidirectional speed in semi-professional soccer players. J Strength Cond Res XX(X): 000-000, 2024-The purpose of this study was to evaluate the effects of an 8-week resisted linear sprint training (RST) program with 2 loading conditions (light vs. very heavy) on linear sprint (LS), curve sprint (CS), and change of direction (COD) performance in young soccer players. Thirty-eight male under-19 soccer players were assessed for 30-m LS, CS, and modified 505 COD tests. Players were randomly allocated into 3 groups: control (n = 18), light (n = 10), and very heavy RST (n = 10). Light and very heavy RST groups performed RST with external loads resulting in a 25 and 75% velocity loss from the player's maximal LS velocity, respectively. The control group did not perform any sprint training. Significant group × time interactions were observed for LS, CS, and COD performances (p < 0.05). The control group showed no performance improvement. Both RST groups showed significant improvements in LS at 10-, 20-, and 30-m (p ≤ 0.03; effect size [ES] ≥ 0.62), whereas no significant changes were observed for the split times (p > 0.05). CS performance was significantly increased by the 2 RST groups (p ≤ 0.03; ES ≥ 0.60), except for light RST on CS right side at 17-m (p = 0.09; ES = 0.46). Change of direction performance was only significantly enhanced by the very heavy RST group (p ≤ 0.001; ES ≥ 0.80). No significant changes between RST groups were observed. In conclusion, using both light and very heavy RST can enhance LS and CS performance, whereas very heavy RST is recommended to optimize COD performance in young soccer players.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546119","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":"Diaphragm Function in Elite Weightlifters With and Without Chronic Low Back Pain and its Impacts on Sports Performance.","authors":"Emma Feng Ming Zhou, Arnold Yu Lok Wong, Juhua Peng, Guohui Lin, Tao Wen, Jianhui Fang, Chufeng Zhou, Siu Ngor Fu","doi":"10.1519/JSC.0000000000004976","DOIUrl":"https://doi.org/10.1519/JSC.0000000000004976","url":null,"abstract":"<p><strong>Abstract: </strong>Zhou, EFM, Wong, AYL, Peng, J, Lin, G, Wen, T, Fang, J, Zhou, C, and Fu, SN. Diaphragm function in elite weightlifters with and without chronic low back pain and its impacts on sports performance. J Strength Cond Res XX(X): 000-000, 2024-The aim of this study was to compare diaphragm function between elite weightlifters with and without chronic low back pain (LBP) and to explore the associations between diaphragm function and sports performance. Forty-nine elite weightlifters aged 16-26 years were recruited, including 29 women (16-25 years, mean ± SD = 19.93 ± 2.70 years) and 20 men (16-26 years, mean ± SD = 20.95 ± 2.68 years). Of these, 23 subjects had chronic LBP. Diaphragm thickness and excursion were assessed using ultrasonography, and maximal inspiratory pressure (MIP), measured with POWERbreathe KH2, served as indicators of diaphragm contractility and strength, respectively. Sports performance was gauged through maximal snatch and clean and jerk lifts. Group differences and performance correlations were analyzed with consideration for confounders. The significance was set at p ≤ 0.05. Weightlifters with chronic LBP demonstrated significantly lower diaphragmatic contractility: diaphragm thickening fraction (by 21%; mean difference [MD] = 0.09, p = 0.04, Cohen's d = 0.69) and diaphragm excursion (by 18%; MD = 0.99, p < 0.01, Cohen's d = 0.89) compared with non-LBP controls. In addition, MIP was positively related to snatch (r = 0.34, p = 0.02) and clean and jerk (r = 0.43, p < 0.01) lifts. This study revealed that elite weightlifters with chronic LBP exhibit reduced diaphragm contractility, and inspiratory muscle force output (primary diaphragm) was associated with lifting performance. Incorporating diaphragm strengthening into training and rehabilitation might enhance performance and aid in LBP management, offering a dual benefit for athletes.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546117","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}