Medicine and Science in Sports and Exercise最新文献

{"title":"Theta-Burst Stimulation Modulates Exercise Performance by Influencing Central Fatigue and Corticospinal Excitability.","authors":"Camilla Martignon, Chiara Barbi, Gianluca Vernillo, Simranjit K Sidhu, Mehran Emadi Andani, Federico Schena, Massimo Venturelli","doi":"10.1249/MSS.0000000000003611","DOIUrl":"10.1249/MSS.0000000000003611","url":null,"abstract":"<p><strong>Purpose: </strong>Theta-burst stimulation (TBS) over the primary motor cortex modulates activity of the underlying neural tissue, but little is known about its consequence on neuromuscular fatigue and its neural correlates. This study aimed to compare the effects of facilitatory versus inhibitory TBS on the neuromuscular fatigue and excitability/inhibition of the corticospinal pathway in an unfatigued/fatigued muscle.</p><p><strong>Methods: </strong>The effects of three TBS protocols (facilitatory/intermittent: iTBS; inhibitory/continuous: cTBS, and sham: sTBS) were tested on exercise performance, neuromuscular function, and corticospinal excitability and inhibition in 20 young healthy participants. Transcranial magnetic and peripheral electrical stimulations were used at baseline, following TBS (unfatigued state), and after a fatiguing sustained contraction (fatigued state) at 35% of the maximal voluntary isometric contraction (MVIC) of the elbow flexors.</p><p><strong>Results: </strong>Time-to-task failure was shorter for cTBS (142 ± 51 s) and longer for iTBS (214 ± 68 s) compared with sTBS (173 ± 65 s) ( P < 0.05). In an unfatigued state, cTBS reduced MVIC and voluntary activation (VA), increased motor-evoked potential, and silent period ( P < 0.05), whereas iTBS did not cause any change. In a fatigued state, MVIC and VA decreased in all TBS sessions ( P < 0.05). However, the reduction in VA was larger after cTBS (Δ -18 ± 18%) compared with iTBS (Δ-3 ± 5%), and sTBS (Δ-9 ± 9%) ( P < 0.001). Furthermore, the increase in motor-evoked potential and silent period were greater for cTBS ( P < 0.05), compared with iTBS and sTBS ( P < 0.05).</p><p><strong>Conclusions: </strong>Facilitatory TBS augments exercise performance that is independent of central parameters and corticospinal mechanisms, whereas inhibitory TBS attenuates exercise performance through an exacerbation in the development of central fatigue and possibly intracortical inhibition.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"716-726"},"PeriodicalIF":4.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142687362","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":"Combined Cold Exposure and Exercise Improves NAFLD: Mechanistic Insights.","authors":"Xue Geng, Zhijian Rao, Jianhong Zhang, Peng Huang, Chaoyi Qu, Dongzhe Wu, Qiangman Wei, Shijie Liu, Xiaokan Zhuang, Jiexiu Zhao","doi":"10.1249/MSS.0000000000003719","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003719","url":null,"abstract":"<p><strong>Introduction: </strong>Non-alcoholic fatty liver disease (NAFLD) affects a quarter of the global population and poses a remarkably serious threat to human health.</p><p><strong>Objectives: </strong>The effect and potential molecular mechanisms of combined cold exposure and exercise intervention on NAFLD remain unclear.</p><p><strong>Materials and methods: </strong>A high-fat diet-induced NAFLD mouse model was utilized. Twenty-four NAFLD mice were divided into three groups and subjected to cold exposure (5 °C), regular-temperature exercise (22 °C), or combined cold exposure and exercise (5 °C) for 8 weeks, 5 days a week, once daily for 1 hour each session. Intervention effects were evaluated through bodyweight, liver mass, liver/bodyweight ratio, blood lipid profile, circulating fibroblast growth factor 21 (FGF21) levels, and liver histopathology. Immunoblotting and quantitative PCR were employed to assess the protein and gene expression of liver FGF21, β-klotho, and FGFR1 to preliminarily elucidate the molecular mechanisms underlying NAFLD improvement by combined cold exposure and exercise.</p><p><strong>Results: </strong>Compared with cold exposure or regular-temperature exercise alone, combined cold exposure and exercise significantly reduced the bodyweight, liver weight, and liver/ bodyweight ratio in the NAFLD mice. The levels of blood lipids, circulating FGF21, and liver glycogen also significantly decreased. Furthermore, the combined intervention significantly reduced liver fat deposition and fibrosis and significantly increased the expression of FGFR1 and β-klotho proteins, suggesting the activation of the FGF21-β-klotho/FGFR1 signaling pathway.</p><p><strong>Conclusions: </strong>This preclinical study demonstrates that combined cold exposure and exercise synergistically alleviates NAFLD progression in animal models, primarily by activating the FGF21-β-klotho/FGFR1 pathway to enhance lipid metabolism and reduce liver injury. These findings highlight the translational potential of dual environmental and behavioral interventions, providing a mechanistic foundation for developing non-pharmacological therapies targeting metabolic pathways in humans, particularly for NAFLD patients resistant to conventional lifestyle modifications or pharmacotherapy.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143803740","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":"In Vivo Biomechanical Interactions Between Bones, Patellar Tendon, and Cartilage Surfaces at the Knee During Cycling.","authors":"Tung-Wu Lu, Kuan-Hsien Wu, Mei-Ying Kuo, Jia-Da Li, Hsuan-Yu Lu, Horng-Chaung Hsu","doi":"10.1249/MSS.0000000000003713","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003713","url":null,"abstract":"<p><strong>Abstract: </strong>Purpose: Stationary cycling is essential in rehabilitation programs for various patient groups, such as knee osteoarthritis and cruciate ligament injuries and reconstruction. The study aimed to measure in vivo the 3D rigid-body and articular surface kinematics of the knee and the patellar tendon orientations during stationary cycling and isolated flexion-extension exercise in healthy young adults using a model-based tracking approach with dual-plane fluoroscopy. Methods: Ten healthy left knees were imaged by CT and MRI to reconstruct subject-specific volumetric bone-cartilage models. The 3D rigid-body and articular surface kinematics and patellar tendon angles during stationary cycling and isolated knee flexion-extension exercise were measured in vivo using a dual-plane fluoroscopy with a voxel-based registration method, compared between tasks and between power and recovery phases. Results: Significant differences in the rigid-body and surface kinematics and patellar tendon orientations were found between the power and recovery phases and between the power phase and isolated knee extension. Compared to the recovery phase, the power phase showed significantly greater external rotations, adductions, and posterior translations for flexions greater than 45° (p < 0.05) with significantly more posterior medial and lateral contact positions for flexion angles less than 45° (p < 0.05) and more vertical patellar tendon orientations for flexion angles lesser than 60° (p < 0.05). Conclusions: The contact locations and loads on the posterior half of the tibial articular surface during the first half of the power phase indicate that stationary cycling as a daily and rehabilitative exercise is safe for people with anterior medial knee OA. Key Words: FLUOROSCOPY, IMAGE REGISTRATION, KNEE JOINT, KINEMATICS, SURFACE KINEMATICS.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772682","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":"Voluntary Exercise Attenuates Tumor Growth in a Preclinical Model of Castration-Resistant Prostate Cancer.","authors":"Nicolas Berger, Benjamin Kugler, Dong Han, Muqing Li, Paul Nguyen, Meaghan Anderson, Susan Patalano-Salsman, Songqi Zhang, Jill Macoska, Changmeng Cai, Kai Zou","doi":"10.1249/MSS.0000000000003712","DOIUrl":"10.1249/MSS.0000000000003712","url":null,"abstract":"<p><strong>Purpose: </strong>To examine the effects of voluntary wheel running on tumor growth and explore potential intratumoral molecular pathways responsible for the beneficial effects of voluntary wheel running on tumor formation and progression in a mouse model of Castration-Resistant Prostate Cancer (CRPC).</p><p><strong>Methods: </strong>Male immunodeficient mice (SCID) were castrated and subcutaneously inoculated with human CWR-22RV1 cancer cells to construct CRPC xenograft model before assigned to either voluntary wheel running (VWR) or sedentary (SED) group (n = 6/group). Tumor size was measured and calculated throughout the study. After three weeks, tumor tissues were collected. mRNA expression of markers of DNA replication, Androgen Receptor (AR) signaling, and mitochondrial dynamics was determined by RT-PCR. Protein expression of mitochondrial dynamics was determined by western blotting. Finally, transcriptomics analysis was performed using the tumor tissues.</p><p><strong>Results: </strong>Voluntary wheel running resulted in smaller tumor volume at the initial stage and attenuated tumor progression throughout the time course (P < 0.05). The reduction of tumor volume in the VWR group coincided with lower mRNA expression of DNA replication markers (MCM2, MCM6, and MCM7), AR signaling (ELOVL5 and FKBP5) and regulatory proteins of mitochondrial fission (Drp1 and Fis1) and fusion (MFN1 and OPA1) when compared to the SED group (P < 0.05). RNA sequencing data further revealed that pathways related to angiogenesis, extracellular matrix formation and endothelial cell proliferation were downregulated.</p><p><strong>Conclusions: </strong>Three weeks of voluntary wheel running was effective in delaying tumor formation and progression, which coincided with reduced transcription of DNA replication, AR signaling targets and mitochondrial dynamics. We further identified a downregulation in molecular pathways related to angiogenesis that may be responsible for the delayed tumor formation and progression by voluntary wheel running.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772743","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":"Physiological Determinants of V̇O2max Increase with Endurance Training in a Group Including Older and Young Adults.","authors":"Robin Faricier, Donald H Paterson, Juan M Murias","doi":"10.1249/MSS.0000000000003707","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003707","url":null,"abstract":"<p><strong>Purpose: </strong>To examine central and peripheral physiological adaptations contributing to increases in maximal oxygen uptake (V̇O2max) following a 12-week of vigorous endurance exercise program in healthy, older and young adults.</p><p><strong>Methods: </strong>Fourteen participants (7 older: 68 ± 7 years and 7 young: 26 ± 7 years; 9 males and 5 females) engaged in a cycling training program 3 times/week for 45 min at ~70%V̇O2max. Changes in V̇O2max, cardiac function, O2 extraction, muscle capillarization, and mitochondrial content from pre- to post-training were examined.</p><p><strong>Results: </strong>The increase in V̇O2max from pre- to post-training for all participants (20 ± 8%) was accompanied by increases in maximal cardiac output (Q̇max: 15 ± 11%), maximal stroke volume (SVmax: 14 ± 12%), muscle fiber cross-sectional area (CSA: 17 ± 21%) and perimeter (P: 7 ± 9%), citrate synthase activity (CS: 144 ± 175%), individual capillary-to-fiber ratio (C:Fi: 32 ± 17%), capillary-to-fiber perimeter exchange index (CPFE: 30 ± 15%), capillary contact (CC: 38 ± 20%), capillary density (CD: 22 ± 17%), and arteriovenous O2 difference (a-vO2diff: 4 ± 6%) (p < 0.05 for all). No training-related variation existed for maximal heart rate (HRmax: -1 ± 4%; p = 0.448). Changes in V̇O2max were positively correlated with Q̇max (r = 0.830: p < 0.001), SVmax (r = 0.655; p = 0.011), CD (r = 0.546; p = 0.043), and CS activity (r = 0.630; p = 0.021). No significant correlations were found for changes in V̇O2max and changes in HRmax, a-vO2diff, muscle fiber CSA and P, CC, C:Fi and CPFE (p > 0.05 for all).</p><p><strong>Conclusions: </strong>Cardiorespiratory fitness improvements were primarily determined by enhancement in central (i.e., cardiac function) and peripheral (i.e., vascularization) adaptations within the O2 transport system as well as the upregulation of mitochondrial aerobic enzymatic activity (i.e., CS activity) at the intracellular level.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772741","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 Moderate-Intensity Interval Training Block Improves Endurance Performance in Well-Trained Cyclists.","authors":"Knut Sindre Mølmen, Ingvill Odden, Margit Dahl Sørensen, Anne Mette Rustaden, Daniel Hammarström, Joar Hansen, Håvard Nygaard, Håvard Hamarsland, Bent R Rønnestad","doi":"10.1249/MSS.0000000000003706","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003706","url":null,"abstract":"<p><strong>Purpose: </strong>This study compared the physiological effects of a moderate-intensity interval training (MIT) microcycle followed by an active recovery period (collectively termed MITblock) with a time-matched regular training period (REG) during the general preparation phase in well-trained cyclists.</p><p><strong>Methods: </strong>Using a randomized crossover design, 30 well-trained male cyclists (maximal oxygen consumption (VO2max), 70.5 (4.6) mL·min-1·kg-1) completed both MITblock and REG. The MIT microcycle involved six interval sessions over seven days with 5-7 × 10-14 min work intervals at a perceived exertion (RPE) of 14-15 on the Borg 6-20 scale. A six-day active recovery period followed before physiological testing. During REG, cyclists performed their regular preparatory-phase training routine, which primarily involved low-intensity exercise. Specific guidelines included completing either two MIT sessions or one MIT session and one high-intensity interval session per week. Endurance performance indicators assessed included changes in 15 min maximal average power output (PO15min), power output at 4 mmol·L-1 [blood lactate] (PO4mmol), 1 min peak power output during incremental testing (POVO2max), and VO2max.</p><p><strong>Results: </strong>Although the Training Impulse (TRIMP) score was not different between MITblock and REG (1944 (436) vs. 1800 (232), respectively; p = 0.27), MITblock resulted in significantly greater improvements than REG in PO4mmol (4.0 (4.4)% vs. -1.3 (3.7)%, p < 0.01), POVO2max (2.5 (4.5)% vs. -0.7 (3.9)%, p < 0.01) and VO2max (2.0 (3.9)% vs. 0.0 (3.5)%, p = 0.05). Changes in PO15min were not statistically different between MITblock and REG (3.9 (8.3)% vs. 0.2 (6.8)%, p = 0.14). During MIT intervals, RPE was 14.4 (0.3), corresponding to 66 (5)% of POVO2max, 85 (3)% of maximal heart rate, and 2.8 (1.1) mmol·L-1 [blood lactate].</p><p><strong>Conclusions: </strong>Six moderate-intensity interval sessions over seven days, followed by a six-day active recovery period, induce improvements in endurance performance indicators compared to a time-matched regular training period in well-trained cyclists.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143657594","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":"BEETter AGING: Short-Term Dietary Nitrate Supplementation Enhances Muscle Contractile Properties in Older But Not in Young Adults.","authors":"Letizia Rasica, Marta Colosio, Alessandra Ferri, Giovanni Baldassarre, Chris Easton, Mia Burleigh, Gianluca Vernillo, Roberto Bottinelli, Mauro Marzorati, Simone Porcelli","doi":"10.1249/MSS.0000000000003708","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003708","url":null,"abstract":"<p><strong>Purpose: </strong>Dietary nitrate (NO3-) supplementation has been shown to improve skeletal muscle contractile function and reduce fatigue, potentially due to alterations in skeletal muscle Ca2+ handling/sensitivity. Since aging muscle can have impaired Ca2+ handling, the aim of the study was to evaluate the effects of dietary NO3- supplementation on muscle contractile properties in young and older adults.</p><p><strong>Methods: </strong>Eleven older (69 ± 4 yrs, O) and 11 young (26 ± 2 yrs, YG) adults consumed either NO3--rich beetroot juice (BR) or placebo (PLA), for 7 days. After supplementations, plantar flexors of dominant leg were evaluated as follow: a) maximal voluntary isometric contraction (MVIC); b) potentiated single twitches (Twpot) and double twitches electrical stimulations at the frequency of 100 Hz (Db100) on the tibial posterior nerve; c) a fatigue isometric (70% of MVIC) test until exhaustion. The force-frequency relationship was assessed with trains of electrical pulses across a wide range of frequencies on the muscle belly of the non-dominant leg.</p><p><strong>Results: </strong>BR supplementation increased plasma [NO3-] and nitrite [NO2-] in both O and YG compared to PLA (more than 7-fold; all P ≤ 0.02). No changes were observed in MVC, Twpot, and Db100 force after BR compared to PLA in both YG and O. Only in O, Db100 area under the curve (-7 ± 6 N·s change from PLA) and half relaxation time (-0.05 ± 0.06 s change from PLA) were significantly reduced. and time to exhaustion (+32 ± 43 s change from PLA) was significantly longer (all P < 0.02) after BR. In O, BR also significantly increased submaximal force produced by trains of electrical pulses (P < 0.001).</p><p><strong>Conclusions: </strong>NO3- supplementation positively affects muscle contractile proprieties, submaximal electrically evoked force production and fatigue resistance in older adults while these positive results were not found in young.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143649423","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 Intense Physical Training on Left Ventricular Hemodynamic Forces in Endurance Athletes: A Feature-Tracking Cardiac Magnetic Resonance Study.","authors":"Yeltay Rakhmanov, Dinara Jumadilova, Bauyrzhan Toktarbay, Zaukiya Kamitova, Aizhan Zankorazhova, Nurmakhan Zholshybek, Nail Khissamutdinov, Makhabbat Bekbossynova, Tairkhan Dautov, Alessandro Salustri","doi":"10.1249/MSS.0000000000003703","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003703","url":null,"abstract":"<p><strong>Purpose: </strong>We sought to evaluate the effect of intensive physical training on left ventricular (LV) hemodynamic forces (HDF) in athletes.</p><p><strong>Methods: </strong>Forty professional endurance athletes were evaluated at the beginning of their training cycle (off-season) and after a period of aerobic isotonic dynamic exercise (peak training period) using cardiac magnetic resonance (CMR). Images were analyzed off-line using dedicated software. LV HDF for the whole cardiac cycle and the different cardiac phases were measured. Standard statistics were used to compare off-season and peak training period values.</p><p><strong>Results: </strong>The average sport experience was 11 ± 7 years. There were no differences in LV volumes, stroke volume, LVEF and LV mass between off-season and peak training CMR. Similarly, there were no changes induced by physical training in the strain parameters. Physical training induced a significant increase of the longitudinal HDF (18.7 vs 21.2, p = 0.023) and an increase of the transverse HDF (3.4 vs 4.0, p = 0.048) throughout the entire heartbeat. After physical training, the peak values and the hemodynamic work (expressed as AUC) of the first part of the systole were significantly higher compared to off-season values (63.9 vs 53.9, p = 0.034; 4.67 vs 3.79, p = 0.015, respectively). The difference in the elastic rebound between off-season and peak training (-0.22 vs -0.37) did not reach statistical significance (p = 0.056).</p><p><strong>Conclusions: </strong>Intense physical training induces an increase in LV HDF of the first part of the systole and of the elastic rebound phase, independent from geometric cardiac remodeling.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143630605","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":"Hamstrings Muscle Architecture and Morphology Following 6 Weeks of an Eccentrically-Biased Romanian Deadlift or Nordic Hamstring Exercise Intervention.","authors":"Scott K Crawford, Caleb Sandberg, Jessica Vlisides, Quinlan Thompson, Samuel J Mosiman, Bryan C Heiderscheit, Jack T Hickey","doi":"10.1249/MSS.0000000000003701","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003701","url":null,"abstract":"<p><strong>Purpose: </strong>This study investigated the effects of a 6-week eccentrically-biased training intervention between Romanian deadlift (RDL) and Nordic hamstring exercises (NHE) on regional hamstring muscle architecture and morphology.</p><p><strong>Methods: </strong>Participants were randomly allocated to an RDL or NHE intervention group and trained twice per week for 6 weeks followed by a 2-week detraining period. Biceps femoris long head (BFlh) architecture (fascicle length [FL] and pennation angle [PA]) and muscle thickness (MT) were measured using extended-field-of-view ultrasound. Anatomical cross-sectional areas (ACSA) of BFlh, semimembranosus, and semitendinosus were also assessed via ultrasound. Muscle architecture and morphology were measured proximally, in the middle, and distally along the thigh. Separate linear mixed effects models were run for each outcome.</p><p><strong>Results: </strong>Thirty-two healthy participants (15 females, 17 males) aged 20.8 (0.9) years were enrolled and allocated to RDL (n = 16) or NHE (n = 16) groups. Following the intervention, BFlh FL increased (0.80 [0.6, 1.0] cm (9%), p < 0.001), while PA decreased uniformly across all regions (-1.2° [-1.5, -0.9] (10%), p < 0.001) and MT did not change (p = 0.29). Both BFlh FL and PA returned to baseline after detraining. No differences were observed between groups for changes in FL (p = 0.55), PA (p = 0.74), or MT (p = 0.48). Hamstrings ACSA increased after the intervention (0.78 cm2 [0.45, 1.11] (10%), p < 0.001) and remained elevated after detraining. There were no significant differences in ACSA between groups after the intervention (p = 0.60).</p><p><strong>Conclusions: </strong>Changes in FL, PA, and ACSA are consistent between an eccentrically-biased RDL and NHE intervention. These findings provide practitioners choice in exercise selection for eliciting adaptations relevant to hamstring injury prevention.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143630608","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":"Cardiometabolic Benefit of Replacing Sedentary Time with Light-Intensity Physical Activity: Compositional Data Analysis of the Nijmegen Exercise Study.","authors":"Koen M van der Sluijs, Janneke I A Vloet, Dick H J Thijssen, Thijs M H Eijsvogels, Esmée A Bakker","doi":"10.1249/MSS.0000000000003705","DOIUrl":"10.1249/MSS.0000000000003705","url":null,"abstract":"<p><strong>Purpose: </strong>The cardiometabolic benefits of replacing sedentary time with light-intensity physical activity (LIPA) are unclear. We studied the associations of hypothetically reallocating sedentary time towards LIPA with changes in cardiometabolic risk factors using thigh-worn accelerometery. We also explored whether reallocation effects differed across subgroups with low, moderate, and high sedentary time and compared proportionally similar reallocations to either LIPA or moderate-to-vigorous physical activity (MVPA).</p><p><strong>Methods: </strong>We assessed physical behaviours across eight consecutive days using thigh-worn accelerometers among adults from the Nijmegen Exercise Study. Multiple cardiometabolic risk factors were assessed and categorised as: 1) anthropometrics, 2) cardiovascular biomarkers, and 3) glucose metabolism. Reallocation effects were estimated for each cardiometabolic risk factor using compositional isotemporal substitution models adjusted for confounders. Analyses were repeated in sedentary time subgroups, i.e. <8.5, 8.5-10, and > 10 hours/day.</p><p><strong>Results: </strong>We included 1,041 participants (64 (standard deviation 11) years; 39.5% female). Reallocating sedentary time towards LIPA was associated with improvements in anthropometrics, some cardiovascular biomarkers, and glucose metabolism; e.g., replacing 60 minutes/day of sedentary time with LIPA was associated with improvements in BMI (-0.28 (-0.42, -0.13) kg/m 2 ), eGFR (0.68 (0.15, 1.20) mL/min/1.73m 2 ), and glucose (-0.05 (-0.08, -0.03) mmol/L). Trends suggested that reallocation benefits were strongest in those with >8.5 hours/day of sedentary time. Proportionally similar replacements of sedentary time with either LIPA or MVPA were associated with similar cardiometabolic benefits.</p><p><strong>Conclusions: </strong>Reallocation of sedentary time to LIPA was associated with improvements in cardiometabolic risk factors, predominantly in anthropometrics and glucose metabolism, with greater benefits in the most sedentary individuals. Time reallocation from sedentary time to LIPA may be an effective and arguably feasible strategy to improve population-wide cardiometabolic health.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143630603","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}