Romina Ledergerber, Paul Ritsche, Eric Lichtenstein, Luisa Prechtl, Oliver Faude, Martin Keller
Low-load blood-flow restriction (BFR) training is a potential alternative to high-load (HL) resistance training, especially when mechanical stress must be minimized. However, its effects on neuromuscular activation remain unclear. This randomized controlled trial compared changes in voluntary activation (VA) and neuromuscular performance following 8 weeks of BFR versus HL knee extensor training and examined the effects of a subsequent 2-week HL phase in both groups. Thirty-seven healthy adults (37-59 years, 22 female) underwent progressive BFR or HL training for 8 weeks (phase 1), followed by 2 weeks of HL training on knee extensor muscles (phase 2). Outcomes included VA, maximal isometric and dynamic leg extension and leg press strength, rate of force development (RFD), and jump performance. Linear mixed models were used to analyze group*time interactions; Cohen's d effect sizes are reported. After both training phases, the BFR group showed smaller improvements than HL in VA (d = -0.31 to -0.37), maximal isometric strength (d = -0.07 to -0.27), dynamic strength (d = -0.18 to -0.75), and RFD (d = -0.48 to -0.54). Jump performance showed trivial between-group differences (d = -0.01 to -0.05). Although a subsequent 2-week HL phase improved outcomes in the BFR group, it did not fully restore neural adaptations to the level of continuous HL training. These findings underscore the essential role of mechanical loading in optimizing neuromuscular function. While BFR may serve as a useful preparatory method in contexts where high loads are initially contraindicated, follow-up HL training is required to maximize neuromuscular adaptation. Trial Registration: This study was preregistered on the Open Science Framework (DOI: 10.17605/OSF.IO/DA6SV).
{"title":"Effects of Low-Load Blood-Flow Restriction Training Versus High-Load Resistance Training on Neuromuscular Performance and Neuromuscular Activation.","authors":"Romina Ledergerber, Paul Ritsche, Eric Lichtenstein, Luisa Prechtl, Oliver Faude, Martin Keller","doi":"10.1111/sms.70203","DOIUrl":"10.1111/sms.70203","url":null,"abstract":"<p><p>Low-load blood-flow restriction (BFR) training is a potential alternative to high-load (HL) resistance training, especially when mechanical stress must be minimized. However, its effects on neuromuscular activation remain unclear. This randomized controlled trial compared changes in voluntary activation (VA) and neuromuscular performance following 8 weeks of BFR versus HL knee extensor training and examined the effects of a subsequent 2-week HL phase in both groups. Thirty-seven healthy adults (37-59 years, 22 female) underwent progressive BFR or HL training for 8 weeks (phase 1), followed by 2 weeks of HL training on knee extensor muscles (phase 2). Outcomes included VA, maximal isometric and dynamic leg extension and leg press strength, rate of force development (RFD), and jump performance. Linear mixed models were used to analyze group*time interactions; Cohen's d effect sizes are reported. After both training phases, the BFR group showed smaller improvements than HL in VA (d = -0.31 to -0.37), maximal isometric strength (d = -0.07 to -0.27), dynamic strength (d = -0.18 to -0.75), and RFD (d = -0.48 to -0.54). Jump performance showed trivial between-group differences (d = -0.01 to -0.05). Although a subsequent 2-week HL phase improved outcomes in the BFR group, it did not fully restore neural adaptations to the level of continuous HL training. These findings underscore the essential role of mechanical loading in optimizing neuromuscular function. While BFR may serve as a useful preparatory method in contexts where high loads are initially contraindicated, follow-up HL training is required to maximize neuromuscular adaptation. Trial Registration: This study was preregistered on the Open Science Framework (DOI: 10.17605/OSF.IO/DA6SV).</p>","PeriodicalId":21466,"journal":{"name":"Scandinavian Journal of Medicine & Science in Sports","volume":"36 1","pages":"e70203"},"PeriodicalIF":3.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12780320/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145918440","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}
Charlotte Nørkjær Eggertsen, Esben Thyssen Vestergaard, Morten Bilde Simonsen, Tine Caroc Warner, Jens Brøndum Frøkjær, Aase Handberg, Line Grønholt Olesen, Anders Grøntved, Anne Vingaard Olesen, Søren Hagstrøm, Jan Christian Brønd, Ryan Godsk Larsen
Children and adolescents with overweight or obesity are less physically active than their lean counterparts. We examined the effects of adding a 3-month high-intensity interval training (HIIT) program to a 12-month lifestyle intervention on physical activity (PA) in children and adolescents with overweight or obesity. Participants were randomized to a 12-month lifestyle intervention (control, N = 83) or a 12-month lifestyle intervention with a 3-month HIIT program (HIIT, N = 90). PA was assessed using accelerometry at baseline, and subsequently at 3 and 12 months. Linear mixed models estimated the mean difference in PA intensity between groups. Associations were explored using Pearson's correlation coefficient. The HIIT group showed a greater increase in moderate-to-vigorous PA (MVPA) after 3 months (p = 0.04), with a mean increase of 8.3 min per day (p < 0.01) compared to 0.9 min per day (p = 0.75) in the control group. At 12 months, there was no difference between the groups (p = 0.64), and MVPA returned to baseline levels. Across randomization, sedentary time increased by 17.5 min per day (p = 0.02) at 3 months and by 29.9 min per day (p < 0.01) at 12 months. Changes from baseline to 12 months in vigorous activity were inversely correlated with changes in BMI z-score (r = -0.26, p = 0.02). Adding a 3-month HIIT program to a 12-month lifestyle intervention in children and adolescents with overweight or obesity increased MVPA at 3 months, but not at 12 months. The inverse correlation between changes in vigorous-intensity PA and changes in BMI z-scores underscores the potential of incorporating vigorous-intensity activities into obesity treatment programs. Trial Registration: ClinicalTrials.gov: NCT05465057.
{"title":"Adding High-Intensity Interval Training to a Multidisciplinary Lifestyle Intervention for Childhood Obesity: Secondary Analysis of a Randomized Controlled Trial to Examine the Effects on Physical Activity Behavior.","authors":"Charlotte Nørkjær Eggertsen, Esben Thyssen Vestergaard, Morten Bilde Simonsen, Tine Caroc Warner, Jens Brøndum Frøkjær, Aase Handberg, Line Grønholt Olesen, Anders Grøntved, Anne Vingaard Olesen, Søren Hagstrøm, Jan Christian Brønd, Ryan Godsk Larsen","doi":"10.1111/sms.70185","DOIUrl":"10.1111/sms.70185","url":null,"abstract":"<p><p>Children and adolescents with overweight or obesity are less physically active than their lean counterparts. We examined the effects of adding a 3-month high-intensity interval training (HIIT) program to a 12-month lifestyle intervention on physical activity (PA) in children and adolescents with overweight or obesity. Participants were randomized to a 12-month lifestyle intervention (control, N = 83) or a 12-month lifestyle intervention with a 3-month HIIT program (HIIT, N = 90). PA was assessed using accelerometry at baseline, and subsequently at 3 and 12 months. Linear mixed models estimated the mean difference in PA intensity between groups. Associations were explored using Pearson's correlation coefficient. The HIIT group showed a greater increase in moderate-to-vigorous PA (MVPA) after 3 months (p = 0.04), with a mean increase of 8.3 min per day (p < 0.01) compared to 0.9 min per day (p = 0.75) in the control group. At 12 months, there was no difference between the groups (p = 0.64), and MVPA returned to baseline levels. Across randomization, sedentary time increased by 17.5 min per day (p = 0.02) at 3 months and by 29.9 min per day (p < 0.01) at 12 months. Changes from baseline to 12 months in vigorous activity were inversely correlated with changes in BMI z-score (r = -0.26, p = 0.02). Adding a 3-month HIIT program to a 12-month lifestyle intervention in children and adolescents with overweight or obesity increased MVPA at 3 months, but not at 12 months. The inverse correlation between changes in vigorous-intensity PA and changes in BMI z-scores underscores the potential of incorporating vigorous-intensity activities into obesity treatment programs. Trial Registration: ClinicalTrials.gov: NCT05465057.</p>","PeriodicalId":21466,"journal":{"name":"Scandinavian Journal of Medicine & Science in Sports","volume":"36 1","pages":"e70185"},"PeriodicalIF":3.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145857601","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}
Naoaki Ito,Yi-Chung Lin,Jack A Martin,Silvia S Blemker,David A Opar,Stephanie A Kliethermes,Bryan C Heiderscheit,
The purpose of this study was to compare stance time and knee joint kinematics between limbs during sprinting in Division-1 collegiate American football athletes with a history of anterior cruciate ligament reconstruction (ACLR). This secondary analysis used data from an ongoing multicenter prospective cohort study of NCAA Division-1 American football athletes. Sprint biomechanics were collected using wearable inertial measurement units during on-field, maximal effort overground sprints. Knee kinematic variables of interest included stance time, knee flexion angle at initial contact, peak knee flexion angle, and knee flexion excursion during the stance phase from 2 to 5 strides near peak sprinting speed. Linear mixed effects models were used to evaluate the main effects of limb (involved vs. uninvolved), time from surgery, and their interaction on variables of interest, adjusted for peak sprint speed. Twenty male athletes (mean age: 21.2 ± 1.3 years; time from surgery: 28.0 ± 18.5 months) were fully participating in American football without limitations at the time of testing and met inclusion criteria. No significant limb × time interactions (p = 0.3-0.60) or main effects of limb (p = 0.23-0.84) or time (p = 0.08-0.84) were observed for any of our variables of interest. Division-1 American football athletes approximately 2 years post-ACLR did not demonstrate asymmetrical knee joint kinematics or stance time during sprinting. While gait asymmetries are commonly observed after ACLR during submaximal walking and running, these differences may diminish at high effort levels required during sprinting. IMU-based methods provide a clinically feasible approach for assessing on-field sprint biomechanics in athletes after ACLR.
{"title":"Exploring Sprint Kinematics in American Football Athletes After Anterior Cruciate Ligament Reconstruction.","authors":"Naoaki Ito,Yi-Chung Lin,Jack A Martin,Silvia S Blemker,David A Opar,Stephanie A Kliethermes,Bryan C Heiderscheit, ","doi":"10.1111/sms.70200","DOIUrl":"https://doi.org/10.1111/sms.70200","url":null,"abstract":"The purpose of this study was to compare stance time and knee joint kinematics between limbs during sprinting in Division-1 collegiate American football athletes with a history of anterior cruciate ligament reconstruction (ACLR). This secondary analysis used data from an ongoing multicenter prospective cohort study of NCAA Division-1 American football athletes. Sprint biomechanics were collected using wearable inertial measurement units during on-field, maximal effort overground sprints. Knee kinematic variables of interest included stance time, knee flexion angle at initial contact, peak knee flexion angle, and knee flexion excursion during the stance phase from 2 to 5 strides near peak sprinting speed. Linear mixed effects models were used to evaluate the main effects of limb (involved vs. uninvolved), time from surgery, and their interaction on variables of interest, adjusted for peak sprint speed. Twenty male athletes (mean age: 21.2 ± 1.3 years; time from surgery: 28.0 ± 18.5 months) were fully participating in American football without limitations at the time of testing and met inclusion criteria. No significant limb × time interactions (p = 0.3-0.60) or main effects of limb (p = 0.23-0.84) or time (p = 0.08-0.84) were observed for any of our variables of interest. Division-1 American football athletes approximately 2 years post-ACLR did not demonstrate asymmetrical knee joint kinematics or stance time during sprinting. While gait asymmetries are commonly observed after ACLR during submaximal walking and running, these differences may diminish at high effort levels required during sprinting. IMU-based methods provide a clinically feasible approach for assessing on-field sprint biomechanics in athletes after ACLR.","PeriodicalId":21466,"journal":{"name":"Scandinavian Journal of Medicine & Science in Sports","volume":"45 1","pages":"e70200"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145949624","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}
Tijs Johannes Verdegaal,Manon Jansen,Peter Bond,Willem de Ronde,Diederik Laurens Smit
Most research on non-prescribed androgen use has focused on men, while women remain underrepresented in the literature, despite unique risks such as virilization and reproductive consequences. This is one of the largest described cohorts of females who use androgen, all of whom underwent in-person consultation, allowing for a more reliable characterization compared to previous studies. We conducted a retrospective chart review of all female patients with a history of non-prescribed androgen use attending a harm reduction clinic in the Netherlands between April 2023 and August 2025. Demographics, training background, motivations, patterns of androgen, and other performance- and image-enhancing drug (PIED) use were extracted. Descriptive statistics were applied. Forty-one women were included (median age 33 years, range 22-59). All performed weekly resistance training, and most (75%) were competitive amateur bodybuilders. The primary motivation was improvement of body composition, muscle size, and strength. Most reported intermittent oral cycles with oxandrolone. Continuous use beyond 1 year was rare. The most frequently used androgen was oxandrolone (88%). Clenbuterol, thyroid hormone, and growth hormone were the most frequent non-androgen PIEDs. Androgen use in this outpatient female cohort was characterized by lower dosages than commonly reported in male cohorts, predominantly oral administration, and motivations tied almost exclusively to bodybuilding or strength sports. While these patterns may reduce some dose-dependent risks such as heart failure, reliance on oral androgens increases the risk of hepatotoxicity and adverse lipid effects. A prospective study with a systematic approach is required to provide more reliable data on the health risk of androgen use in women.
{"title":"Androgen Use Among Female Amateur Athletes: A Retrospective Analysis.","authors":"Tijs Johannes Verdegaal,Manon Jansen,Peter Bond,Willem de Ronde,Diederik Laurens Smit","doi":"10.1111/sms.70207","DOIUrl":"https://doi.org/10.1111/sms.70207","url":null,"abstract":"Most research on non-prescribed androgen use has focused on men, while women remain underrepresented in the literature, despite unique risks such as virilization and reproductive consequences. This is one of the largest described cohorts of females who use androgen, all of whom underwent in-person consultation, allowing for a more reliable characterization compared to previous studies. We conducted a retrospective chart review of all female patients with a history of non-prescribed androgen use attending a harm reduction clinic in the Netherlands between April 2023 and August 2025. Demographics, training background, motivations, patterns of androgen, and other performance- and image-enhancing drug (PIED) use were extracted. Descriptive statistics were applied. Forty-one women were included (median age 33 years, range 22-59). All performed weekly resistance training, and most (75%) were competitive amateur bodybuilders. The primary motivation was improvement of body composition, muscle size, and strength. Most reported intermittent oral cycles with oxandrolone. Continuous use beyond 1 year was rare. The most frequently used androgen was oxandrolone (88%). Clenbuterol, thyroid hormone, and growth hormone were the most frequent non-androgen PIEDs. Androgen use in this outpatient female cohort was characterized by lower dosages than commonly reported in male cohorts, predominantly oral administration, and motivations tied almost exclusively to bodybuilding or strength sports. While these patterns may reduce some dose-dependent risks such as heart failure, reliance on oral androgens increases the risk of hepatotoxicity and adverse lipid effects. A prospective study with a systematic approach is required to provide more reliable data on the health risk of androgen use in women.","PeriodicalId":21466,"journal":{"name":"Scandinavian Journal of Medicine & Science in Sports","volume":"20 1","pages":"e70207"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145986264","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}
Benke Xu, Wenjun Li, Jijun Fan, Guoying Zhang, Guoxiao Sun
This study investigated whether a 6-week exercise snacks (ES) intervention enhanced cognitive performance and explored prefrontal neurovascular coupling mechanisms using functional near-infrared spectroscopy (fNIRS). In a randomized controlled trial, 89 high school students were assigned to an ES group (n = 47; three 90-s high-intensity sessions per day, 3 days weekly) or a control group (n = 42). Cognitive performance was assessed via the Stroop task; prefrontal cortex activation and functional connectivity were measured using multi-channel fNIRS. Linear mixed models revealed that ES significantly improved reaction times for both congruent (β = -39.35, p = 0.001) and incongruent tasks (β = -39.87, p = 0.01), with enhanced activation in the right frontopolar area and left dorsolateral prefrontal cortex during congruent and incongruent tasks. ES also strengthened prefrontal functional connectivity. Mediation analyses confirmed that L-DLPFC-R-FPA connectivity mediated the intervention's effect on reaction time (indirect effect β = -74.10, 95% CI: -99.57 to -50.16). These findings suggest that ES enhances neural efficiency, reflected by faster reaction times without compromising accuracy, underpinned by optimizing prefrontal neural synergy. A daily total of 4.5 min of high-intensity micro-exercise serves as a feasible school-based intervention.
本研究利用功能近红外光谱（fNIRS）研究了为期6周的运动零食（ES）干预是否能提高认知能力，并探讨了前额叶神经血管耦合机制。在一项随机对照试验中，89名高中生被分配到ES组（n = 47；每天3次90秒高强度课程，每周3天）或对照组（n = 42）。通过Stroop任务评估认知表现；使用多通道fNIRS测量前额皮质激活和功能连通性。线性混合模型显示，ES显著改善了一致性任务（β = -39.35, p = 0.001）和不一致性任务（β = -39.87, p = 0.01）的反应时间，在一致性和不一致性任务中，右侧额极区和左侧背外侧前额叶皮层的激活增强。ES还增强了前额叶功能连接。中介分析证实，L-DLPFC-R-FPA连通性介导了干预对反应时间的影响（间接效应β = -74.10, 95% CI: -99.57至-50.16）。这些研究结果表明，通过优化前额叶神经协同作用，ES可以提高神经效率，反映在更快的反应时间而不影响准确性。每天4.5分钟的高强度微运动是一种可行的校本干预措施。
{"title":"Exercise Snacks Improve Cognitive Processing Efficiency: Evidence From Behavioral and fNIRS Studies.","authors":"Benke Xu, Wenjun Li, Jijun Fan, Guoying Zhang, Guoxiao Sun","doi":"10.1111/sms.70192","DOIUrl":"10.1111/sms.70192","url":null,"abstract":"<p><p>This study investigated whether a 6-week exercise snacks (ES) intervention enhanced cognitive performance and explored prefrontal neurovascular coupling mechanisms using functional near-infrared spectroscopy (fNIRS). In a randomized controlled trial, 89 high school students were assigned to an ES group (n = 47; three 90-s high-intensity sessions per day, 3 days weekly) or a control group (n = 42). Cognitive performance was assessed via the Stroop task; prefrontal cortex activation and functional connectivity were measured using multi-channel fNIRS. Linear mixed models revealed that ES significantly improved reaction times for both congruent (β = -39.35, p = 0.001) and incongruent tasks (β = -39.87, p = 0.01), with enhanced activation in the right frontopolar area and left dorsolateral prefrontal cortex during congruent and incongruent tasks. ES also strengthened prefrontal functional connectivity. Mediation analyses confirmed that L-DLPFC-R-FPA connectivity mediated the intervention's effect on reaction time (indirect effect β = -74.10, 95% CI: -99.57 to -50.16). These findings suggest that ES enhances neural efficiency, reflected by faster reaction times without compromising accuracy, underpinned by optimizing prefrontal neural synergy. A daily total of 4.5 min of high-intensity micro-exercise serves as a feasible school-based intervention.</p>","PeriodicalId":21466,"journal":{"name":"Scandinavian Journal of Medicine & Science in Sports","volume":"36 1","pages":"e70192"},"PeriodicalIF":3.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145879006","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}
Bas Van Hooren,Tjeu Souren,Félix Miqueu,Bart C Bongers
The validity and between-day reliability of cardiopulmonary exercise testing (CPET) systems remain largely unexplored. We therefore evaluate the validity and between-day technological and biological reliability of five popular CPET systems for assessing respiratory variables, substrate use, and energy expenditure during simulated and real human exercise. The following systems were assessed: Vyntus CPX, Oxycon Pro, VO2 Master, KORR, and Calibre. A metabolic simulator was used to simulate breath-by-breath gas exchange. The values measured by each system (minute ventilation (V̇E), breathing frequency (BF), oxygen uptake (V̇O2), carbon dioxide production (V̇CO2), respiratory exchange ratio (RER), energy from carbohydrates and fats, and total energy expenditure) were compared to the simulated values to assess the validity. Six well-trained participants cycled 5% below their first ventilatory threshold on 2 days to verify the validity in human exercise. Between-session reliability was assessed in both the simulation and human experiments to determine technological and biological variability. Absolute percentage errors during the simulations ranged from 0.69% to 5.56% for V̇E, 0.92% to 1.44% for BF, 3.12% to 7.86% for V̇O2, 4.07% to 12.1% for V̇CO2, 1.21% to 6.94% for RER, 2.83% to 48.8% for Kcal from carbohydrates, 14.1% to 50.3% for Kcal from fats, and 4.21% to 6.98% for total energy expenditure. Between-session variability during simulation (i.e., technological variability) ranged from 0.46% to 3.15% for V̇O2 and 0.71% to 4.99% for V̇CO2. The error and between-day variability of the error for respiratory gas variables, substrate, and energy use differed substantially between systems. Biological and technological V̇O2 and V̇CO2 variability, respectively, accounted for ~60%-70% and 40%-30% of the variability in repeated human testing.
{"title":"Technological and Biological Reliability, and Validity of Five Different CPET Systems During Simulated and Human Exercise.","authors":"Bas Van Hooren,Tjeu Souren,Félix Miqueu,Bart C Bongers","doi":"10.1111/sms.70184","DOIUrl":"https://doi.org/10.1111/sms.70184","url":null,"abstract":"The validity and between-day reliability of cardiopulmonary exercise testing (CPET) systems remain largely unexplored. We therefore evaluate the validity and between-day technological and biological reliability of five popular CPET systems for assessing respiratory variables, substrate use, and energy expenditure during simulated and real human exercise. The following systems were assessed: Vyntus CPX, Oxycon Pro, VO2 Master, KORR, and Calibre. A metabolic simulator was used to simulate breath-by-breath gas exchange. The values measured by each system (minute ventilation (V̇E), breathing frequency (BF), oxygen uptake (V̇O2), carbon dioxide production (V̇CO2), respiratory exchange ratio (RER), energy from carbohydrates and fats, and total energy expenditure) were compared to the simulated values to assess the validity. Six well-trained participants cycled 5% below their first ventilatory threshold on 2 days to verify the validity in human exercise. Between-session reliability was assessed in both the simulation and human experiments to determine technological and biological variability. Absolute percentage errors during the simulations ranged from 0.69% to 5.56% for V̇E, 0.92% to 1.44% for BF, 3.12% to 7.86% for V̇O2, 4.07% to 12.1% for V̇CO2, 1.21% to 6.94% for RER, 2.83% to 48.8% for Kcal from carbohydrates, 14.1% to 50.3% for Kcal from fats, and 4.21% to 6.98% for total energy expenditure. Between-session variability during simulation (i.e., technological variability) ranged from 0.46% to 3.15% for V̇O2 and 0.71% to 4.99% for V̇CO2. The error and between-day variability of the error for respiratory gas variables, substrate, and energy use differed substantially between systems. Biological and technological V̇O2 and V̇CO2 variability, respectively, accounted for ~60%-70% and 40%-30% of the variability in repeated human testing.","PeriodicalId":21466,"journal":{"name":"Scandinavian Journal of Medicine & Science in Sports","volume":"11080 1","pages":"e70184"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033963","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}
Mikkel Holm Hjortshoej, Hemant Juneja, René Brüggebusch Svensson, Robert Bennike Herzog, Mathilde Lundgaard‐Nielsen, Frederik Kronvold Nielsen, Mette With Wulff, Amanda Emilie Olsen, Janus Damm Nybing, Philip Hansen, Jesper Petersen, Michael Kjaer, Per Aagaard, Stig Peter Magnusson, Christian Couppé
Patellar tendinopathy (PT) is a debilitating overuse injury, and one of the current recommended treatments is heavy slow resistance training (HSRT); Recently, low‐load resistance training combined with blood flow restriction (LL‐BFRT) has been advocated as a clinically relevant rehabilitation tool for PT since it does not involve large joint and tissue stresses and may accelerate recovery. This study aimed to investigate the effect of LL‐BFRT compared with HSRT at 3, 6, 12 (primary endpoint), and 52 weeks. Participants with chronic unilateral PT were randomized to a 12‐week rehabilitation program based on either LL‐BFRT ( n = 16) or HSRT ( n = 20). The primary outcome was pain (numerical rating scale (NRS) 0–10) during a single‐leg decline squat (SLDS). Secondary outcome variables included the Victorian Institute of Sports Assessment‐Patella questionnaire (VISA‐P), maximal isometric knee extensor strength, patellar tendon morphology assessed by ultrasonography (swelling, vascularization), and magnetic resonance imaging (MRI). Comparable clinically relevant improvements in pain (NRS during SLDS, least squares mean ± SEM) were observed in LL‐BFRT (LL‐BFRT: 0 weeks 3.9 ± 0.5, 12 weeks 2.2 ± 0.5, 52 weeks 1.8 ± 0.5) and HSRT (0 weeks 4.2 ± 0.4, 12 weeks 2.2 ± 0.4, 52 weeks 1.1 ± 0.5) ( p < 0.0001). Likewise, clinically relevant improvements were reported on the VISA‐P score. LL‐BFRT and HSRT resulted in comparable short‐term and long‐term clinical improvements in males with chronic PT. These data advocate that LL‐BFRT represents an effective rehabilitation tool in the treatment of chronic PT, while preventing high joint and tendon loads. Trial Registration: Clinicaltrials.org (NCT04550013)
{"title":"Effect of Low‐Load Blood‐Flow Restricted Training Versus Heavy Slow Resistance Training in Unilateral Patellar Tendinopathy: A Randomized Clinical Trial","authors":"Mikkel Holm Hjortshoej, Hemant Juneja, René Brüggebusch Svensson, Robert Bennike Herzog, Mathilde Lundgaard‐Nielsen, Frederik Kronvold Nielsen, Mette With Wulff, Amanda Emilie Olsen, Janus Damm Nybing, Philip Hansen, Jesper Petersen, Michael Kjaer, Per Aagaard, Stig Peter Magnusson, Christian Couppé","doi":"10.1111/sms.70186","DOIUrl":"https://doi.org/10.1111/sms.70186","url":null,"abstract":"Patellar tendinopathy (PT) is a debilitating overuse injury, and one of the current recommended treatments is heavy slow resistance training (HSRT); Recently, low‐load resistance training combined with blood flow restriction (LL‐BFRT) has been advocated as a clinically relevant rehabilitation tool for PT since it does not involve large joint and tissue stresses and may accelerate recovery. This study aimed to investigate the effect of LL‐BFRT compared with HSRT at 3, 6, 12 (primary endpoint), and 52 weeks. Participants with chronic unilateral PT were randomized to a 12‐week rehabilitation program based on either LL‐BFRT ( <jats:italic>n</jats:italic> = 16) or HSRT ( <jats:italic>n</jats:italic> = 20). The primary outcome was pain (numerical rating scale (NRS) 0–10) during a single‐leg decline squat (SLDS). Secondary outcome variables included the Victorian Institute of Sports Assessment‐Patella questionnaire (VISA‐P), maximal isometric knee extensor strength, patellar tendon morphology assessed by ultrasonography (swelling, vascularization), and magnetic resonance imaging (MRI). Comparable clinically relevant improvements in pain (NRS during SLDS, least squares mean ± SEM) were observed in LL‐BFRT (LL‐BFRT: 0 weeks 3.9 ± 0.5, 12 weeks 2.2 ± 0.5, 52 weeks 1.8 ± 0.5) and HSRT (0 weeks 4.2 ± 0.4, 12 weeks 2.2 ± 0.4, 52 weeks 1.1 ± 0.5) ( <jats:italic>p</jats:italic> < 0.0001). Likewise, clinically relevant improvements were reported on the VISA‐P score. LL‐BFRT and HSRT resulted in comparable short‐term and long‐term clinical improvements in males with chronic PT. These data advocate that LL‐BFRT represents an effective rehabilitation tool in the treatment of chronic PT, while preventing high joint and tendon loads. Trial Registration: <jats:ext-link xmlns:xlink=\"http://www.w3.org/1999/xlink\" xlink:href=\"http://clinicaltrials.org\">Clinicaltrials.org</jats:ext-link> (NCT04550013)","PeriodicalId":21466,"journal":{"name":"Scandinavian Journal of Medicine & Science in Sports","volume":"4 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145829869","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}
J. M. Guy, F. Schnell, S. Cade, S. Doutreleau, B. Gérardin, S. Armero, F. Chagué, C. Hédon, S. Guérard, F. Ivanes, L. Chevalier
The benefits of regular physical activity are well demonstrated in secondary cardiovascular prevention, but data on high‐intensity exercise after percutaneous coronary intervention (PCI) remain limited. This study aimed to assess whether resuming high‐intensity exercise within the first year after PCI was associated with an increased risk of cardiovascular (CV) events. We prospectively followed 1154 patients who had undergone PCI without prior revascularization. All patients engaged in regular exercise prior to PCI. We compared the 1‐year outcome of patients who resumed high‐intensity exercise with the remaining patients. Within the first year 91.6% of patients resumed exercise (18.0% high‐intensity, 41.0% moderate‐intensity, 32.6% light‐intensity), predominantly endurance‐based (93.3%). No CV death was reported, atrial fibrillation occurred in 27 patients (2.3%), ischemic stroke in 4 (0.3%), ventricular arrhythmias in 9 (0.8%), acute heart failure in 8 (0.7%), and new coronary event in 30 (2.6%); including 21 new stenoses, 4 in‐stent restenoses, and 5 stent thromboses. Four patients experienced an acute coronary syndrome, including 2 during exercise. The 205 patients in the high‐intensity exercise group reported a higher training load (7.0 [5.0–8.0] hours/week vs. 4.0 [2.0–6.0], p < 0.0001). The incidence of CV events did not differ significantly between the groups (total CV events: 5.9% vs. 7.0%, p = 0.541; new coronary events: 1.5% vs. 2.9%, p = 0.250 respectively in the high‐intensity exercise group vs. the remaining patients). These findings indicate no observed increase in short‐term CV events among previously active patients resuming high‐intensity exercise after PCI, but further studies are required to determine whether these observations are generalisable.
有规律的身体活动在心血管二级预防方面的益处已得到充分证明，但经皮冠状动脉介入治疗（PCI）后高强度运动的数据仍然有限。本研究旨在评估PCI术后一年内恢复高强度运动是否与心血管（CV）事件风险增加相关。我们前瞻性随访了1154例术前未行PCI血运重建的患者。所有患者在PCI术前都进行了定期锻炼。我们比较了恢复高强度运动的患者与剩余患者的1年预后。在第一年，91.6%的患者恢复了运动（18.0%高强度，41.0%中强度，32.6%轻强度），主要是耐力运动（93.3%）。无CV死亡报告，房颤27例（2.3%），缺血性卒中4例（0.3%），室性心律失常9例（0.8%），急性心力衰竭8例（0.7%），新冠状动脉事件30例（2.6%）；其中21例新发狭窄，4例支架内再狭窄，5例支架内血栓形成。4例患者出现急性冠状动脉综合征，其中2例在运动期间。高强度运动组的205例患者报告了更高的训练负荷（7.0[5.0-8.0]小时/周vs. 4.0[2.0-6.0]小时/周，p < 0.0001）。两组间CV事件的发生率无显著差异（总CV事件：5.9% vs. 7.0%, p = 0.541；新冠状动脉事件：1.5% vs. 2.9%, p = 0.250）。这些发现表明，在PCI术后恢复高强度运动的患者中，没有观察到短期心血管事件的增加，但需要进一步的研究来确定这些观察结果是否可推广。
{"title":"High‐Intensity Exercise After Percutaneous Coronary Intervention in Previously Physically Active Patients: One‐Year Clinical Outcomes","authors":"J. M. Guy, F. Schnell, S. Cade, S. Doutreleau, B. Gérardin, S. Armero, F. Chagué, C. Hédon, S. Guérard, F. Ivanes, L. Chevalier","doi":"10.1111/sms.70194","DOIUrl":"https://doi.org/10.1111/sms.70194","url":null,"abstract":"The benefits of regular physical activity are well demonstrated in secondary cardiovascular prevention, but data on high‐intensity exercise after percutaneous coronary intervention (PCI) remain limited. This study aimed to assess whether resuming high‐intensity exercise within the first year after PCI was associated with an increased risk of cardiovascular (CV) events. We prospectively followed 1154 patients who had undergone PCI without prior revascularization. All patients engaged in regular exercise prior to PCI. We compared the 1‐year outcome of patients who resumed high‐intensity exercise with the remaining patients. Within the first year 91.6% of patients resumed exercise (18.0% high‐intensity, 41.0% moderate‐intensity, 32.6% light‐intensity), predominantly endurance‐based (93.3%). No CV death was reported, atrial fibrillation occurred in 27 patients (2.3%), ischemic stroke in 4 (0.3%), ventricular arrhythmias in 9 (0.8%), acute heart failure in 8 (0.7%), and new coronary event in 30 (2.6%); including 21 new stenoses, 4 in‐stent restenoses, and 5 stent thromboses. Four patients experienced an acute coronary syndrome, including 2 during exercise. The 205 patients in the high‐intensity exercise group reported a higher training load (7.0 [5.0–8.0] hours/week vs. 4.0 [2.0–6.0], <jats:italic>p</jats:italic> < 0.0001). The incidence of CV events did not differ significantly between the groups (total CV events: 5.9% vs. 7.0%, <jats:italic>p</jats:italic> = 0.541; new coronary events: 1.5% vs. 2.9%, <jats:italic>p</jats:italic> = 0.250 respectively in the high‐intensity exercise group vs. the remaining patients). These findings indicate no observed increase in short‐term CV events among previously active patients resuming high‐intensity exercise after PCI, but further studies are required to determine whether these observations are generalisable.","PeriodicalId":21466,"journal":{"name":"Scandinavian Journal of Medicine & Science in Sports","volume":"56 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145829868","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}
Yago Medeiros Dutra, Paloma Tavares Mendonça, Arthur J. Cheng, Juan M. Murias, Alessandro Moura Zagatto
This study investigated the effects of cold‐water immersion (11°C, CWI 11° ) and hot‐water immersion (41°C, HWI 41° ) on components of fatigability after distinct high‐intensity endurance running protocols. Participants completed either continuous running at the velocity associated with the respiratory compensation point (vRCP; CONT 100%RCP , n = 12) or intermittent running at 50% above vRCP (HIIT 150%RCP , n = 10). Assessments were performed at baseline, immediately after, and at 2, 4, and 24 h postexercise. These included voluntary and evoked knee‐extensor contractions, countermovement jumps, mood state, cardiac autonomic modulation, and cardiorespiratory and perceptual responses during submaximal brief runs. Compared to placebo and regardless of preceding running protocol, CWI 11° enhanced cardiac vagal modulation at 2 h postexercise (condition × time interaction, p < 0.05), whereas HWI 41° reduced oxygen consumption rate during submaximal brief runs within 24 h postexercise (condition effect, p < 0.05). Furthermore, compared to placebo, HWI 41° increased vastus lateralis activation during maximal voluntary contractions (RMS/M‐wave amp ) 2 and 4 h after the CONT 100%RCP , while CWI 11° increased it at the same time points after the HIIT 150%RCP (condition × time interactions, p < 0.05). The efficacy of CWI 11° and HWI 41° as recovery interventions after running depended on the specific component of fatigability being assessed and the preceding exercise protocol. While CWI 11° increased cardiac vagal modulation and HWI 41° reduced oxygen consumption rate in post‐intervention submaximal brief runs, neither intervention improved knee‐extensor voluntary or involuntary peak force, perceptual responses, or mood disturbance. Both HWI 41° and CWI 11° enhanced muscle activation during maximal voluntary contractions; however, this benefit was observed with HWI 41° after continuous endurance running and with CWI 11° following high‐intensity intermittent running.
{"title":"Hot‐ and Cold‐Water Immersion Do Not Alter Performance or Perceived Fatigability but Improve Muscle Activation, Cardiac Vagal Modulation, and Cardiorespiratory Recovery After Distinct Running Protocols","authors":"Yago Medeiros Dutra, Paloma Tavares Mendonça, Arthur J. Cheng, Juan M. Murias, Alessandro Moura Zagatto","doi":"10.1111/sms.70191","DOIUrl":"https://doi.org/10.1111/sms.70191","url":null,"abstract":"This study investigated the effects of cold‐water immersion (11°C, CWI <jats:sub>11°</jats:sub> ) and hot‐water immersion (41°C, HWI <jats:sub>41°</jats:sub> ) on components of fatigability after distinct high‐intensity endurance running protocols. Participants completed either continuous running at the velocity associated with the respiratory compensation point (vRCP; CONT <jats:sub>100%RCP</jats:sub> , <jats:italic>n</jats:italic> = 12) or intermittent running at 50% above vRCP (HIIT <jats:sub>150%RCP</jats:sub> , <jats:italic>n</jats:italic> = 10). Assessments were performed at baseline, immediately after, and at 2, 4, and 24 h postexercise. These included voluntary and evoked knee‐extensor contractions, countermovement jumps, mood state, cardiac autonomic modulation, and cardiorespiratory and perceptual responses during submaximal brief runs. Compared to placebo and regardless of preceding running protocol, CWI <jats:sub>11°</jats:sub> enhanced cardiac vagal modulation at 2 h postexercise (condition × time interaction, <jats:italic>p</jats:italic> < 0.05), whereas HWI <jats:sub>41°</jats:sub> reduced oxygen consumption rate during submaximal brief runs within 24 h postexercise (condition effect, <jats:italic>p <</jats:italic> 0.05). Furthermore, compared to placebo, HWI <jats:sub>41°</jats:sub> increased <jats:italic>vastus lateralis</jats:italic> activation during maximal voluntary contractions (RMS/M‐wave <jats:sub>amp</jats:sub> ) 2 and 4 h after the CONT <jats:sub>100%RCP</jats:sub> , while CWI <jats:sub>11°</jats:sub> increased it at the same time points after the HIIT <jats:sub>150%RCP</jats:sub> (condition × time interactions, <jats:italic>p</jats:italic> < 0.05). The efficacy of CWI <jats:sub>11°</jats:sub> and HWI <jats:sub>41°</jats:sub> as recovery interventions after running depended on the specific component of fatigability being assessed and the preceding exercise protocol. While CWI <jats:sub>11°</jats:sub> increased cardiac vagal modulation and HWI <jats:sub>41°</jats:sub> reduced oxygen consumption rate in post‐intervention submaximal brief runs, neither intervention improved knee‐extensor voluntary or involuntary peak force, perceptual responses, or mood disturbance. Both HWI <jats:sub>41°</jats:sub> and CWI <jats:sub>11°</jats:sub> enhanced muscle activation during maximal voluntary contractions; however, this benefit was observed with HWI <jats:sub>41°</jats:sub> after continuous endurance running and with CWI <jats:sub>11°</jats:sub> following high‐intensity intermittent running.","PeriodicalId":21466,"journal":{"name":"Scandinavian Journal of Medicine & Science in Sports","volume":"28 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145829870","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}
João Pedro Nunes, Kazunori Nosaka, Anthony J. Blazevich
It remains unclear whether muscle functional adaptations to concentric (CON‐RT) and eccentric (ECC‐RT) resistance training are most specific to their exercise characteristics or the structural adaptations they evoke. In this study, the effects of CON‐RT and ECC‐RT programs matched for relative intensity and work on regional hypertrophy, muscle architecture, and function were compared, and associations between the outcomes were explored. Twelve trained young men (25.5 ± 3.6 years) completed 18 isokinetic ankle dorsiflexion exercise sessions over 6 weeks: CON‐RT in one leg and ECC‐RT in the other (2–4 sets, 6–10 maximal repetitions, 10°/s). Tibialis anterior size and architecture (ultrasound imaging) and maximum voluntary dorsiflexion function (isokinetic dynamometry) were assessed. Muscle thickness increased similarly between conditions and across proximal‐distal regions (8%), pennation angle increased more with CON‐RT (8%) than ECC‐RT (4%), and fascicle length increased only after ECC‐RT (6%). Functional adaptations were more closely associated with specific structural adaptations than with contraction mode, velocity, or angle. Isometric torque increased similarly in both conditions overall (8%), but CON‐RT improved only at shorter muscle lengths and shifted the peak torque angle leftward, whereas ECC‐RT improved at both shorter and longer lengths and broadened the torque‐angle plateau, which was correlated with fascicle length increases. ECC‐RT produced greater increases in both eccentric (13%) and concentric torques (17%) than CON‐RT (3%, 9%, respectively), and changes were similar across velocities. Changes in pennation angle were associated with dynamic strength changes. These findings suggest that muscle function adapts to the structural changes induced by training, regardless of the training mode used.
{"title":"The Training Specificity Versus Structural Adaptation Paradox: Differential Effects of Isokinetic Concentric and Eccentric Resistance Training on Muscle Architecture and Function in Young Men","authors":"João Pedro Nunes, Kazunori Nosaka, Anthony J. Blazevich","doi":"10.1111/sms.70166","DOIUrl":"https://doi.org/10.1111/sms.70166","url":null,"abstract":"It remains unclear whether muscle functional adaptations to concentric (CON‐RT) and eccentric (ECC‐RT) resistance training are most specific to their exercise characteristics or the structural adaptations they evoke. In this study, the effects of CON‐RT and ECC‐RT programs matched for relative intensity and work on regional hypertrophy, muscle architecture, and function were compared, and associations between the outcomes were explored. Twelve trained young men (25.5 ± 3.6 years) completed 18 isokinetic ankle dorsiflexion exercise sessions over 6 weeks: CON‐RT in one leg and ECC‐RT in the other (2–4 sets, 6–10 maximal repetitions, 10°/s). Tibialis anterior size and architecture (ultrasound imaging) and maximum voluntary dorsiflexion function (isokinetic dynamometry) were assessed. Muscle thickness increased similarly between conditions and across proximal‐distal regions (8%), pennation angle increased more with CON‐RT (8%) than ECC‐RT (4%), and fascicle length increased only after ECC‐RT (6%). Functional adaptations were more closely associated with specific structural adaptations than with contraction mode, velocity, or angle. Isometric torque increased similarly in both conditions overall (8%), but CON‐RT improved only at shorter muscle lengths and shifted the peak torque angle leftward, whereas ECC‐RT improved at both shorter and longer lengths and broadened the torque‐angle plateau, which was correlated with fascicle length increases. ECC‐RT produced greater increases in both eccentric (13%) and concentric torques (17%) than CON‐RT (3%, 9%, respectively), and changes were similar across velocities. Changes in pennation angle were associated with dynamic strength changes. These findings suggest that muscle function adapts to the structural changes induced by training, regardless of the training mode used.","PeriodicalId":21466,"journal":{"name":"Scandinavian Journal of Medicine & Science in Sports","volume":"30 1","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145801240","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}
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