Medicine and Science in Sports and Exercise最新文献

{"title":"HbA1c and Liver Fat After 16 Weeks of Fasted versus Fed Exercise Training in Adults With Type 2 Diabetes.","authors":"Jordan L Rees, Devyn Walesiak, Richard Thompson, Diana Mager, Peter Senior, Normand G Boulé","doi":"10.1249/MSS.0000000000003552","DOIUrl":"10.1249/MSS.0000000000003552","url":null,"abstract":"<p><strong>Purpose: </strong>Exercise-nutrient timing is of interest for people with type 2 diabetes (T2D) as a potential method to optimize glycemic control. However, the optimal nutritional environment for exercise is not well understood over the long term. The Fasted Exercise for Type 2 Diabetes (FED) Trial compared 16 wk of fasted versus postprandial morning exercise on glycated hemoglobin (HbA1c) and liver proton density fat fraction (PDFF).</p><p><strong>Methods: </strong>Twenty adults with T2D were recruited and randomized to complete exercise after an overnight fast versus after their morning meal. Participants walked three mornings per week, progressing to 180 min·wk -1 over 16 wk.</p><p><strong>Results: </strong>Groups were balanced with five males and five females each. Sixteen participants completed the trial (8 in each group, 50% female). Age, HbA1c, and PDFF were 59.8 ± 9.0 yr, 7.2 ± 0.7%, and 9.3 ± 4.1%, respectively. On average, both groups completed 98% of their walking sessions but there was no change in HbA1c (-0.2%, P = 0.588). However, one participant from each group had changes in their glucose-lowering medication during the trial, and when excluded, the fasted training group had greater improvements in HbA1c compared with the postprandial group (-0.3% vs 0.0%, P = 0.033). There was no difference in changes in liver PDFF between groups (-1.6% vs 0.3%, P = 0.221) but visceral fat and intramuscular fat decreased to a greater extent after fasted exercise.</p><p><strong>Conclusions: </strong>Although our study had a small sample size, it suggests that exercise after an overnight fast can have high adherence and represents an option for people with T2D to improve longer-term indicators of glycemia and ectopic fat depots.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"106-114"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142290797","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":"Manual Interstructural Release Procedure Can Alter Muscle Shear Modulus.","authors":"Tomoko Yamashita, Yasuhide Yoshitake, Hironori Watanabe, Sohei Washino, Kazuyoshi Gamada, Minoru Shinohara","doi":"10.1249/MSS.0000000000003535","DOIUrl":"10.1249/MSS.0000000000003535","url":null,"abstract":"<p><strong>Purpose: </strong>Interstructural release (ISR) procedure to skeletal muscles is believed to attenuate adhesion between neighboring muscles and alleviate subjective symptoms, including perceived stiffness and associated pain. However, objective evidence about the effect of ISR on the mechanical properties of the muscles is limited. The purpose of this study was to test the acute effect of ISR on the shear modulus of adjacent muscles. It was hypothesized that ISR applied to the border between synergistic muscles would acutely reduce the resting shear modulus of the involved muscle.</p><p><strong>Methods: </strong>To assess the effect of ISR, the shear modulus of the resting peroneus longus (PL) and soleus (SOL) muscles was measured at various ankle joint positions (inversion/eversion) before and after interventions in nine nonsymptomatic male individuals (age: 21.9 ± 1.4 yr, height: 170 ± 6.6 cm, body mass: 64.3 ± 4.0 kg). Potential muscle activity during the measurement was assessed by recording surface electromyogram from these muscles. The interventions were ISR to the lower leg between the deep fascia of the PL and SOL and sham (massage).</p><p><strong>Results: </strong>As the ankle joint position was passively varied toward inversion, the shear modulus increased substantially in PL and decreased moderately in SOL. Shear modulus of the proximal PL in the most inverted position increased acutely after ISR (by 11.4 ± 5.8%, P <0.001), but not after the sham, without any change in the amplitude of electromyogram.</p><p><strong>Conclusions: </strong>These results provide objective evidence that the ISR procedure can acutely alter shear modulus, at least in a specific site in a resting muscle.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"44-53"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141976071","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":"Electromyography of Sedentary Behavior: Identifying Potential for Cardiometabolic Risk Reduction.","authors":"Suvi Lamberg, Christian J Brakenridge, David W Dunstan, Taija Finni, Genevieve N Healy, Neville Owen, Arto J Pesola","doi":"10.1249/MSS.0000000000003544","DOIUrl":"10.1249/MSS.0000000000003544","url":null,"abstract":"<p><strong>Introduction: </strong>Muscle activation during interruptions to prolonged sedentary time is a hypothesized mechanism underlying observed cardiometabolic benefits. We examined associations of quadriceps and hamstring muscle activity patterns with cardiometabolic risk markers and how these patterns varied between different sitting-interruption countermeasures.</p><p><strong>Methods: </strong>Electromyographic (EMG) data (shorts) were gathered for 1 to 2 d from healthy adults in a free-living study ( n = 172, age 40.9 ± 12.9, BMI 23.6 ± 1.3) and a laboratory-based study ( n = 12, age 47.0 ± 7.7, BMI 30.0 ± 4.7). Patterns examined were average EMG (aEMG;%EMG MVC ); EMG activity duration (% above signal baseline 3 μV); and usual (weighted medians) EMG activity bout amplitude (%EMG MVC ) and duration (s). In the free-living study, these were regressed against risk markers (waist, fat percentage, fasting plasma glucose, total cholesterol, high-density lipid cholesterol, low-density lipid cholesterol, triglycerides); in the laboratory study, EMG patterns for the muscle groups were compared between sitting and the active countermeasures.</p><p><strong>Results: </strong>In the free-living study, lower-extremity muscles displayed minimal overall activity, with hamstrings and quadriceps using only 2.6% and 2.0% of their capacity (%EMG MVC ), respectively, and being active for 30% and 25% of the time. Higher hamstring aEMG and EMG activity duration were beneficially associated with waist, high-density lipid cholesterol and fat percentage (duration only) and a longer quadriceps usual EMG activity bout duration was beneficially associated with fasting plasma glucose. In the laboratory study, compared with prolonged sitting, active seated or upright active-interruption countermeasures modified these EMG patterns; brief (6 min) walking and simple resistance activities (SRA) were more beneficial than was a bout of standing (30 min) with the SRAs being the only intervention that matched daily aEMG levels.</p><p><strong>Conclusions: </strong>Upright and physically active interruptions to sitting appear to be required to increase the typically low muscle engagement observed in free-living contexts, promoting muscle activity patterns that may help ameliorate cardiometabolic risk.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"11-22"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142109225","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":"Clinical and Cardiometabolic Effects of Reducing Sedentary Behavior in Postmenopausal Women with Rheumatoid Arthritis.","authors":"Ana Jessica Pinto, Kamila Meireles, Tiago Peçanha, Bruna Caruso Mazzolani, Fabiana Infante Smaira, Diego Rezende, Fabiana Braga Benatti, Ana Cristina DE Medeiros Ribeiro, Ana Lúcia DE Sá Pinto, Fernanda Rodrigues Lima, Hamilton Roschel, Bruno Gualano","doi":"10.1249/MSS.0000000000003546","DOIUrl":"10.1249/MSS.0000000000003546","url":null,"abstract":"<p><strong>Purpose: </strong>We investigated the effects of a 4-month intervention targeting sedentary behavior on sedentary time and physical activity level, clinical parameters, cardiometabolic risk factors, inflammatory markers, and health-related quality of life in postmenopausal women with rheumatoid arthritis.</p><p><strong>Methods: </strong>This was a 4-month, parallel-group, randomized controlled trial ( ClinicalTrials.gov identifier: NCT03186924). One hundred and three postmenopausal rheumatoid arthritis patients were randomized (1:1) to either a newly developed intervention targeting sedentary behavior (Take a STAND for Health [TS4H]) or standard of care (SOC). Sedentary behavior (primary outcome) and physical activity levels, clinical parameters, anthropometric parameters and body composition, blood samples and oral glucose tolerance test, blood pressure, muscle function, and health-related quality of life were assessed at baseline (Pre) and after 4 months (Post). Between- and within-group differences were tested using linear mixed models following the intention-to-treat principle.</p><p><strong>Results: </strong>Total sedentary time, time in prolonged sitting bouts, standing, and stepping did not change in either group (all P ≥ 0.337). No significant between- and within-group differences were detected for any of the clinical parameters, markers of cardiometabolic health and inflammation, and health-related quality of life variables (all P ≥ 0.136). Among responders in TS4H group (those who reduced sedentary time by ≥30 min·d -1 ), Pre to Post IL-10 concentrations tended to reduce (group-time: P = 0.086; estimated mean difference [EMD]: -12.0 pg·mL -1 [-23.5 to -0.6], P = 0.037) and general health (group-time: P = 0.047; EMD: 10.9 A.U. [-1.1 to 22.9], P = 0.086) and overall physical health tended to improve (group-time: P = 0.067; EMD: 7.9 A.U. [-0.9 to 16.6], P = 0.089).</p><p><strong>Conclusions: </strong>TS4H did not change sedentary behavior, physical activity levels, clinical, cardiometabolic, inflammatory, or health-related quality of life outcomes. However, TS4H tended to reduce IL-10 levels and improve health-related quality of life in responders.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"23-32"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142290791","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":"Evaluating Gait with Force Sensing Insoles 6 Months after Anterior Cruciate Ligament Reconstruction: An Autograft Comparison.","authors":"Rachel E Cherelstein, Christopher Kuenze, Matthew S Harkey, Michelle C Walaszek, Corey Grozier, Emily R Brumfield, Jennifer N Lewis, Garrison A Hughes, Edward S Chang","doi":"10.1249/MSS.0000000000003554","DOIUrl":"10.1249/MSS.0000000000003554","url":null,"abstract":"<p><strong>Introduction: </strong>Aberrant knee mechanics during gait 6 months after anterior cruciate ligament reconstruction (ACLR) are associated with markers of knee cartilage degeneration. The purpose of this study was to compare loading during walking gait in quadriceps tendon, bone-patellar tendon-bone (BPTB), and hamstring tendon autograft patients 6 months post-ACLR using loadsol single sensor insoles, and to evaluate associations between loading and patient-reported outcomes.</p><p><strong>Methods: </strong>Seventy-two patients (13 to 40 yr) who underwent unilateral, primary ACLR with BPTB, quadriceps tendon, or hamstring tendon autograft completed treadmill gait assessment, the International Knee Documentation Committee (IKDC) survey, and the ACL-Return to Sport after Injury (ACL-RSI) survey 6 ± 1 months post-ACLR. Ground reaction forces were collected using loadsols. Limb symmetry indices (LSI) for peak impact force (PIF), loading response instantaneous loading rate (ILR), and loading response average loading rate (ALR) were compared between groups using separate analyses of covariance. Survey scores were compared between groups using one-way ANOVAs. The relationships between IKDC, ACL-RSI, and LSI were compared using Pearson's product moment correlation coefficients.</p><p><strong>Results: </strong>There were no significant differences between graft sources for LSI in PIF, ILR, ALR, or impulse. Patient-reported knee function was significantly different between graft source groups with the BPTB group reporting the highest IKDC scores; however, there was no significant difference between groups for ACL-RSI score. There were no significant associations between IKDC score, ACL-RSI score, and biomechanical symmetry among any of the graft source groups.</p><p><strong>Conclusions: </strong>Autograft type does not influence PIF, ILR, ALR, or impulse during walking 6 months post-ACLR. Limb symmetry during gait is not strongly associated with patient-reported outcomes regardless of graft source. Loadsols appear to be a suitable tool for use in the clinical rehabilitation setting.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"210-216"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142290795","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 Temporal Effects of Altitude and Low Energy Availability Manipulation on Resting Metabolic Rate in Female Race Walkers.","authors":"Megan A Kuikman, Alannah K A McKay, Rachel McCormick, Nicolin Tee, Brent Vallance, Kathryn E Ackerman, Rachel Harris, Kirsty J Elliott-Sale, Trent Stellingwerff, Louise M Burke","doi":"10.1249/MSS.0000000000003534","DOIUrl":"10.1249/MSS.0000000000003534","url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to investigate the temporal effects of ~1800 m altitude exposure and energy availability (EA) manipulation on resting metabolic rate (RMR).</p><p><strong>Methods: </strong>Twenty elite female race walkers underwent a 3-wk training camp at an altitude of ~1800 m. During the first 2 wk, athletes consumed a high EA (HEA) diet of 45 kcal·kg fat-free mass (FFM) -1 ·d -1 . During the final week, half the athletes consumed a low EA (LEA) diet of 15 kcal·kg FFM -1 ·d -1 , whereas the others continued on an HEA diet. Athletes followed individualized training plans throughout the study. To assess the effect of altitude on RMR, athletes in the HEA group had RMR measured at baseline (~580 m) before altitude exposure (Pre-alt), at 36 h (36h-alt), 2 wk (Wk2-alt), and 3 wk into altitude exposure (Wk3-alt), and at 36 h post-altitude exposure at ~580 m (36h-post). To assess the effect of LEA exposure on RMR while at altitude, athletes in the LEA group underwent RMR measurements at Pre-alt and before (Wk2-alt) and after the 7 d of LEA (Wk3-alt).</p><p><strong>Results: </strong>Compared with Pre-alt, the RMR of HEA athletes was increased at 36h-alt (+5.3% ± 3.1%; P = 0.026) and Wk2-alt (+4.9% ± 4.9%; P = 0.049), but was no longer elevated at Wk3-alt (+1.7% ± 4.2%; P = 0.850). The RMR of HEA athletes at 36h-post was lower than all timepoints at altitude ( P < 0.05) but was not different from Pre-alt (-3.9% ± 7.2%; P = 0.124). The 7-d period of LEA exposure at altitude did not affect RMR ( P = 0.347).</p><p><strong>Conclusions: </strong>RMR was transiently increased with ~1800-m altitude exposure in female athletes and was unaffected by short-term LEA. However, the altitude-induced increase was small (~25-75 kcal·d -1 ) and was unlikely to have clinically significant implications for daily energy requirements.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"123-133"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142004543","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":"Assessment of Maximum Heart Rate Prediction Equations in Adults at Low and High Risk of Cardiovascular Disease.","authors":"Pierre Boulay, Ahmed Ghachem, Paul Poirier, Ronald J Sigal, Glen P Kenny","doi":"10.1249/MSS.0000000000003540","DOIUrl":"10.1249/MSS.0000000000003540","url":null,"abstract":"<p><strong>Purpose: </strong>Maximum heart rate (HRmax) is commonly used to estimate exercise intensity. Since direct measurement of HRmax is not always practical, prediction equations were developed. However, most equations have not been properly validated in adults at low and high risk of cardiovascular disease (CVD). We sought to: 1) assess the accuracy of commonly used equations to predict HRmax among adults at low and high CVD risk and, 2) determine if SuperLearner (SL) modeling combining base machine algorithms could improve HRmax prediction.</p><p><strong>Methods: </strong>A total of 1208 participants (61.6 ± 7.3 yr; 62.7% male) were included. HRmax was measured during a maximal cardiorespiratory exercise test. Predicted HRmax was estimated using the following published equations: Fox, Åstrand, Tanaka, Gelish and Gulati, and a SL model. Bland-Altman analyses as well as performance indicators such as root mean squared error (RMSE) and Lin's Concordance Correlation Coefficient were performed.</p><p><strong>Results: </strong>All predicted HRmax-derived equations were positively associated with measured HRmax (women: r = 0.31; men: r = 0.46, P ≤ 0.001) but to a greater extent using a SL model (women: r = 0.47; men: r = 0.59, P ≤ 0.001). Overall, all equations tended to overestimate measured HRmax, with a RMSE which varied between 10.4 and 12.3 bpm. Although the SL model outperformed other equations, with no significant difference between measured and predicted HRmax, RMSE remained high (11.3 bpm). Lack of accuracy was mainly observed among adults with low aerobic fitness and with CVD risk factors, such as obesity, diabetes, and hypertension.</p><p><strong>Conclusions: </strong>We showed that commonly used equations and the SL model have insufficient accuracy to predict HRmax among adults. The performance of the prediction equations varied considerably according to the population clinical characteristics such as the presence of CVD risk factors or a low aerobic fitness.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"60-69"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142004581","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":"Baseline Symptoms and Neurocognitive Performance across Collision, Contact, and Noncontact Female High School Athletes.","authors":"Jessie R Oldham, David R Howell, Corey J Lanois, Paul D Berkner, Grant L Iverson, Rebekah C Mannix, William P Meehan","doi":"10.1249/MSS.0000000000003539","DOIUrl":"10.1249/MSS.0000000000003539","url":null,"abstract":"<p><strong>Purpose: </strong>Our purpose was to represent a rare cohort of female collision sport athletes and investigate the association between sport type (collision, contact, and noncontact), symptoms, and performance on baseline neurocognitive assessments.</p><p><strong>Methods: </strong>We conducted a cross-sectional study using baseline computerized neurocognitive scores (Immediate Postconcussion Assessment and Cognitive Testing [ImPACT]) of 75,128 female high school student-athletes (age, 15.27 ± 1.05 yr) playing multiple sports. The dependent variables were verbal memory, visual memory, visual motor speed, reaction time, and total symptom score. The independent variable was sport type, categorized as collision, contact, noncontact, adjusted for the effect of the following covariables: age, concussion history, and comorbidities (learning disability, ADHD, psychiatric condition, headaches, migraines, speech therapy, special education, and repeating one of more years of school) using multivariable regression models.</p><p><strong>Results: </strong>Female collision sport athletes reported significantly higher symptoms (9.81 ± 12.63) at baseline compared with contact (5.78 ± 9.25) or noncontact (6.39 ± 9.74) sport athletes ( P < 0.001). Using noncontact sports as a reference, there was no significant association between collision sport participation and cognitive composite scores (verbal memory: β = -0.57, 95% confidence interval = -1.80 to 0.66, P = 0.38; visual memory: β = -0.83, 95% confidence interval = -2.46 to 0.79, P = 0.31; visual motor speed: β = -0.21, 95% confidence interval = -1.01, 0.59, P = 0.61; reaction time: β = 0.01, 95% confidence interval = -0.01 to 0.02, P = 0.29).</p><p><strong>Conclusions: </strong>Participation in collision sports appears to be associated with baseline symptoms but not neurocognitive functioning among female adolescent athletes.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"54-59"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141976070","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":"Pacing Behavior Development: The Role of Task Experience and the Presence of Competitors.","authors":"Stein Gerrit Paul Menting, Mohammed Khudair, Marije Titia Elferink-Gemser, Florentina Johanna Hettinga","doi":"10.1249/MSS.0000000000003538","DOIUrl":"10.1249/MSS.0000000000003538","url":null,"abstract":"<p><strong>Introduction: </strong>Self-regulation of effort during exercise (i.e., pacing) is a determinant of exercise performance, which develops during childhood and adolescence. Yet the various aspects of pacing under development, such as the capability to use task experience and retain the task goal in the presence of other competitors, have remained relatively unexplored.</p><p><strong>Methods: </strong>Nine adolescents (14.9 ± 2.1 yr old) and 14 adults (24.2 ± 3.2 yr old) completed four 4-km cycling trials in a well-controlled laboratory setting. After one familiarization visit, trials were performed in random order: alone, with the goal to finish the trial as fast as possible (AloneTime), with a competitor and the same goal (CompTime), or with a competitor and the goal to finish first (CompFirst). Within each age-group, repeated-measures ANOVA ( P < 0.05) examined the differences in the estimated task duration, pacing behavior (distribution of mean power output per 500 m), and performance (finish time) between visits (4) or conditions (3).</p><p><strong>Results: </strong>In contrast to adults ( P < 0.05, ηp2 > 0.20), adolescents did not exhibit a change in estimation of task duration, pacing behavior, or performance over repeated visits ( P > 0.05, ηp2 < 0.10). Adolescents altered their pacing behavior in the presence of a competitor independent of the task goal (CompTime and CompFirst), whereas adults only demonstrated this alteration when instructed to finish first (CompFirst).</p><p><strong>Conclusions: </strong>Adolescents are still developing the capability 1) to use experience from previous tasks to adjust their pacing behavior and 2) to inhibit the intuitive action of engaging with the competitor to retain the more abstract task goal of finishing the trial as fast as possible. These findings establish novel experimental evidence for the underpinnings of pacing behavior development.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"154-162"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141976072","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":"Physical Fitness and Exercise Performance of Transgender Women.","authors":"Athiwat Saitong, Witthawat Naeowong, Daroonwan Suksom, Hirofumi Tanaka","doi":"10.1249/MSS.0000000000003536","DOIUrl":"10.1249/MSS.0000000000003536","url":null,"abstract":"<p><strong>Introduction: </strong>In spite of the evolving participation of transgender adults in exercise and sports, research investigating the physical fitness of transgender women remains scarce in the scientific literature.</p><p><strong>Methods: </strong>In this cross-sectional study, a variety of reference standard measures of physical fitness of transgender women who had undergone gender-affirming orchiectomy (30 ± 4 yr; n = 15) and who had not (27 ± 4 yr: n = 15) were compared with reference males (28 ± 5 yr; n = 15) and reference females (29 ± 5 yr; n = 15) who were matched for age and estimated physical activity level. Transgender women had been undergoing feminizing gender-affirming therapy for 8 to 10 yr.</p><p><strong>Results: </strong>Height and lean mass of arms, legs, and trunk (measured via dual-energy x-ray absorptiometry) of transgender women were greater than those of reference females but lower than those of reference males (all P < 0.05). No significant differences were found in isokinetic muscular torque between reference females and transgender women. Both absolute and relative measures of maximal oxygen consumption were greater in reference males than in reference females and transgender women (all P < 0.05) with no significant difference between the latter two groups. Reference males had greater peak Wingate anaerobic power (expressed in both absolute and relative to body weight), countermovement jump, and squat jump than reference females and transgender women (all P < 0.05). There were no significant differences in anaerobic power between reference females and transgender women. The results on the field tests, including agility T-test and sprint running acceleration, were consistent with the anaerobic power tests. There were no statistical differences in any of the physical fitness measures between transgender women with and without orchiectomy.</p><p><strong>Conclusions: </strong>Transgender women demonstrated similar levels of reference standard measures of physical fitness to females that were significantly lower than males.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"134-143"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141976073","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}