Medicine and Science in Sports and Exercise最新文献

{"title":"Linear Modelling of the V̇O2/PO-Relationship during Constant Work Rate Exercise.","authors":"Lena Stuer, Jan Boone, Patrick Mucci, Alessandro L Colosio, Jan G Bourgois, Kevin Caen","doi":"10.1249/MSS.0000000000003647","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003647","url":null,"abstract":"<p><strong>Introduction: </strong>The linear and continuous increase in power output (PO) during ramp incremental (RI) exercise causes a distinct V̇O2/PO relationship compared to constant work rate (CWR) exercise. Current methods enabling a translation of ramp-derived PO to CWR PO assume a linear development of the CWR V̇O2/PO relationship in the heavy-intensity domain. This study aimed to model the RI versus CWR V̇O2/PO relationship to investigate whether the loss of mechanical efficiency above GET develops linearly. A second aim was to assess the reliability of ramp-derived parameters incorporated in translation strategies.</p><p><strong>Methods: </strong>Fourteen healthy young participants (7 males; 7 females) performed a RI test and several CWR tests across the heavy- and severe-intensity domains in order to model the RI and CWR V̇O2/PO relationships. The CWR relationship was fitted using linear, polynomial and exponential models. Root mean square error (RMSE) and Akaike information criterion (AICC) were determined to evaluate the model's goodness-of-fit. For reliability purposes, target PO of CWR tests were achieved using a preceding RI portion, similar to the initial RI test.</p><p><strong>Results: </strong>The linear fit of the CWR V̇O2/PO relationship was associated with the lowest RMSE and AICC. The associated R2 for the heavy-intensity domain was 0.94. Reliability measures were excellent for baseline V̇O2 and acceptable to good for s1-ramp and s2- ramp. For MRT, a high variability was observed.</p><p><strong>Conclusions: </strong>This study confirmed that the CWR V̇O2/PO relationship in the heavy-intensity domain is linear. Based on these results, it is justified to apply correction strategies that mind the different dynamics of V̇O2 during RI versus CWR exercise.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142971614","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":"Screening for Relative Energy Deficiency in Sport: Detection of Clinical Indicators in Female Endurance Athletes.","authors":"Paulina Wasserfurth, Robin Halioua, Désirée Toepffer, Zoë Lautz, Helena Engel, Anna Katarina Melin, Monica Klungland Torstveit, Malte Christian Claussen, Karsten Koehler","doi":"10.1249/MSS.0000000000003644","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003644","url":null,"abstract":"<p><strong>Purpose: </strong>The purpose was to evaluate the individual and combined use of the Low Energy Availability in Females Questionnaire (LEAF-Q) and the Brief Eating Disorder in Athletes Questionnaire (BEDA-Q) to detect clinical indicators associated with Relative Energy Deficiency in Sport (REDs).</p><p><strong>Methods: </strong>In this cross-sectional study, 50 female endurance athletes training ≥4x/week completed the LEAF-Q and BEDA-Q and were assessed for presence of selected REDs indicators. Athletes meeting the criteria for mild or more severe REDs severity/risk according to the International Olympic Committee REDs Clinical Assessment Tool Version 2 (IOC REDs CAT2) were classified as REDs cases. Diagnostic properties of the German versions of the LEAF-Q and BEDA-Q were assessed at different cut-offs using receiver operating characteristics calculations.</p><p><strong>Results: </strong>Fourteen (28%) athletes were classified as REDs cases. The LEAF-Q had a sensitivity of 79% and a specificity of 50%, with a positive predictive value (PPV) of 38% and negative predictive value (NPV) of 86%. For detection of disordered eating behaviour/eating disorder (DE/ED), the BEDA-Q showed a sensitivity and specificity of 71% and 76%, respectively, with a PPV of 68% and NPV of 79%. Out of 14 REDs cases, nine (64%) scored positive in the LEAF-Q and BEDA-Q. Two athletes (14%) scored positive only in the LEAF-Q and one athlete scored positive only in the BEDA-Q. Two REDs cases remained undetected by both questionnaires.</p><p><strong>Conclusions: </strong>Among German female endurance athletes, the LEAF-Q and BEDA-Q are good screening tools to detect REDs cases with mild or more severe severity/risk as classified according to the IOC REDs CAT2. Further clinical assessments should be initiated when athletes score positive in at least one of the questionnaires.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142950950","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":"Comparative Effects of Different Exercise Types on Cardiovascular Health and Executive Function in Sedentary Young Individuals.","authors":"Jinglin Huang, Lu Leng, Min Hu, Xuyan Cui, Xu Yan, Ziqing Liu, Kangle Wang, Jiarui Wu, Shan He, Weiji Deng, Peilun Li, Yilin Chen, Dongdong Gao, Yuan Wei, Junhao Huang","doi":"10.1249/MSS.0000000000003645","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003645","url":null,"abstract":"<p><strong>Purpose: </strong>The present study aimed to compare the impacts of different exercise types on cardiovascular health and executive function in sedentary young individuals, and to determine the associations between cardiovascular function and executive function (EF) after exercise.</p><p><strong>Methods: </strong>Sixty-three sedentary participants were randomly divided into high-intensity interval training (HIIT), moderate-intensity continuous training (MICT), resistance exercise (RE), and control groups. Macro- and microvascular endothelial function were assessed using brachial artery flow-mediated dilation and fingertip reactive hyperemia index, respectively. Arterial stiffness was evaluated through carotid-femoral pulse wave velocity, ankle-brachial index, and augmentation index. EF performance was evaluated using the Stroop and N-back tasks. Functional near-infrared spectroscopy was employed to measure cortical activation and real-time oxyhemoglobin concentration (Oxy-Hb) changes in different cerebral regions. Key circulating biomarkers for vascular and cognitive function, including BDNF, irisin, VEGF, IGF-1, and TNF-α, were measured using enzyme-linked immunosorbent assays.</p><p><strong>Results: </strong>Eight weeks of HIIT, MICT, and RE effectively improved macro- and microvascular endothelial function while reducing arterial stiffness in sedentary young individuals. Furthermore, exercise-induced increase in BDNF level was correlated with enhanced macrovascular endothelial function, while increase in IGF-1 level was associated with enhanced microvascular endothelial function and reduced arterial stiffness. Notably, both HIIT and MICT, but not RE, efficiently enhanced Oxy-Hb level in certain brain regions, such as the FPA and DLPFC, leading to the improvement in EF performance. Exercise-induced increase in Oxy-Hb level and EF performance were correlated with enhanced BDNF level and endothelial function and reduced arterial stiffness.</p><p><strong>Conclusions: </strong>Our study demonstrated that 8 weeks of HIIT, MICT, and RE effectively improved endothelial function in both macro- and microvessels, and arterial stiffness among sedentary young individuals. However, HIIT and MICT, but not RE, notably increased blood oxygen level in the FPA and DLPFC brain regions and improved EF performance. Due to the efficiency and time-saving features of HIIT, the present study highlights HIIT as an effective exercise prescription for promoting vascular and EF in sedentary young individuals. Importantly, the observed improvements in cardiovascular function following exercise training is pivotal in improving EF, and elevated circulating levels of biomarkers like BDNF and IGF-1, induced by exercise, are involved in the regulatory mechanisms.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142950947","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":"Associations Between Walking Pace, APOE-ε4 Genotype, and Brain Health in Middle-Aged to Older Adults.","authors":"Daniel H Aslan, M Katherine Sayre, Pradyumna K Bharadwaj, Madeline Ally, Silvio Maltagliati, Mark H C Lai, Rand R Wilcox, Yann C Klimentidis, Gene E Alexander, David A Raichlen","doi":"10.1249/MSS.0000000000003646","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003646","url":null,"abstract":"<p><strong>Abstract: </strong>Poor physical function and possession of the e4 allele of the apolipoprotein E (APOE) gene are each associated with increased dementia risk, but it is unclear how these exposures interact to influence brain health. Purpose: To investigate whether self-reported walking pace (a marker of physical function) and the presence of APOE-ε4 allele interact to modify brain health outcomes. Methods: We used data from a prospective cohort study of middle-aged to older adults from the UK Biobank who self-reported walking pace (slow or steady-to-brisk), and who were initially free of dementia (n = 415,110). Incident all-cause dementia was obtained from hospital and death registry records, and structural brain volumes (right and left hippocampus volumes, total gray matter volume, and volume of white matter hyperintensities) were measured from a subset of participants (n = 33,113). Cox proportional hazard models and generalized linear models were used to assess associations between exposures and outcomes. Results: Slow walking pace and the presence of APOE-ε4 allele were associated with increased dementia risk [HR = 1.79 (1.66,1.93), p < 0.001; HR = 3.06 (2.90,3.23), p < 0.001, respectively], and there was an interaction between these associations, indicating that the association of walking pace with dementia risk is modified by APOE-ε4 status [(reference group: HRSteady-Brisk/APOE-ε4- = 1); HRSlow/APOE-ε4- = 2.03(1.84,2.25), p < 0.001; HRSteady-Brisk/APOE-ε4+ = 3.21(3.02,3.41), p < 0.001; HRSlow/APOE-ε4+ = 4.99 (4.48,5.58), p < 0.001]. Slow self-reported walking pace was associated with worse brain volume outcomes and these associations were not modified by APOE-ε4 genotype. Conclusions: These results suggest walking pace and APOE-ε4 status independently influence brain volume outcomes, but both factors independently and jointly contribute to increased dementia risk. Individuals with both risk factors (slow walking pace and APOE-ε4 allele) show the strongest associations with dementia risk.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142950944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Validity and Reliability of the Tampa Scale for Kinesiophobia for Adolescents with Heart Disease.","authors":"David A White, William R Black, Emily Cramer, Lindsey Malloy-Walton, Mollie Walton, Laura Martis, Brandy Enneking, Kelli M Teson, Jessica S Watson, Jami Gross-Toalson","doi":"10.1249/MSS.0000000000003642","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003642","url":null,"abstract":"<p><strong>Abstract: </strong>Kinesiophobia (KP) is the fear of movement or physical activity (PA) that is related to a medical condition. In adolescents, KP is associated with depression, anxiety, and impaired quality of life (QoL). Adolescents with heart disease (HD) often avoid PA. Factors that may moderate PA avoidance, such as KP, have not been adequately studied in this population. Purpose: To assess the validity and reliability of a newly adapted Tampa Scale for KP for adolescents with HD (TSK-Heart-A). Methods: The TSK-Heart-A survey consists of 17 Likert scale items, producing a summary score (SS) ranging from 17 (low KP) to 68 (high KP). Following content and face validity, adolescents (age 12-18 years) with arrhythmia disorders or Fontan palliation were recruited. The PROMIS pediatric anxiety and depression short forms, PedsQL generic core and cardiac module, and a PA questionnaire for adolescents (PAQ-A) were used for criterion validity. The TSK-Heart-A was completed twice (20.4 ± 6.3 days apart) for assessment of internal and test-retest reliability. Pearson correlations and Cronbach's alpha determined validity and reliability, respectively. Results: Adolescents (n = 63) were 15.5 ± 1.8 years-old, 50.8% female, and 69.8% had arrhythmia disorder. Mean TSK-Heart-A SS was 33.8 ± 7.8 (range: 20 to 56). The TSK-Heart-A SS correlated significantly with PROMIS T-scores (anxiety: 49.7 ± 12.2, r = 0.48; depression: 46.9 ± 12.7, r = 0.41), PedsQL score (generic QoL: 75.2 ± 18.9, r = -0.61; cardiac QoL: 74.7 ± 17.5, r = -0.56), and PAQ-A (score: 2.0 ± 0.7, r = -0.35). Test-retest and internal reliability had a total score of r = 0.77 (p = 0.89). Conclusions: The new TSK-Heart-A survey is valid and reliable and suggests KP is present in some adolescents with HD.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142950953","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":"Sex Differences in Ambulatory Biomechanics: A Meta-Analysis Providing a Mechanistic Insight into Knee Osteoarthritis.","authors":"Momoko Yamagata, Tetsuya Kimura, Alison H Chang, Hirotaka Iijima","doi":"10.1249/MSS.0000000000003549","DOIUrl":"10.1249/MSS.0000000000003549","url":null,"abstract":"<p><strong>Purpose: </strong>Females typically present with a higher prevalence of knee osteoarthritis (KOA), and such a higher prevalence may be due to unique knee biomechanics during walking. However, the sex-dependent ambulatory mechanics has been yet to be clarified. To address this critical knowledge gap, this study implemented a series of computational approaches 1) to identify sex-related knee joint biomechanics during ambulation in persons with KOA and 2) to compare these biomechanical measures between individuals with versus without KOA, stratified by sex.</p><p><strong>Methods: </strong>We searched five electronic databases for studies reporting sex-specific knee biomechanics in persons with and/or without KOA. Summary estimates were computed using random-effects meta-analysis and stratified by sex.</p><p><strong>Results: </strong>The systematic review identified 18 studies (308 males and 383 females with KOA; 740 males and 995 females without KOA). A series of meta-analyses identified female-specific knee biomechanics in a disease-dependent manner. Females with KOA had lower first peak knee adduction moment and peak knee adduction compared with male counterparts. On the other hand, healthy females had lower peak knee flexion moment than male counterparts. Effect estimate in each meta-analysis displayed poor quality of evidence according to the GRADE approach.</p><p><strong>Conclusions: </strong>The current study is the first to consider sex as a biological variable into ambulatory mechanics in the development of KOA. We discovered that sex-dependent alterations in knee biomechanics is a function of the presence of KOA, indicating that KOA disease may be a driver of the sex-dependent biomechanical alterations or vice versa. Although no strong conclusion can be drawn because of the low quality of evidence, these findings provide new insight into the sex differences in ambulatory knee biomechanics and progression of KOA.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"144-153"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142290799","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":"Consuming Whey Protein with Added Essential Amino Acids, Not Carbohydrate, Maintains Postexercise Anabolism While Underfed.","authors":"Jess A Gwin, David D Church, Jillian T Allen, Marques A Wilson, Christopher T Carrigan, Nancy E Murphy, Alyssa N Varanoske, Lee M Margolis, Robert R Wolfe, Arny A Ferrando, Stefan M Pasiakos","doi":"10.1249/MSS.0000000000003541","DOIUrl":"10.1249/MSS.0000000000003541","url":null,"abstract":"<p><strong>Purpose: </strong>Energy deficiency decreases muscle protein synthesis (MPS), possibly due to greater whole-body essential amino acid (EAA) requirements and reliance on energy stores. Whether energy deficit-induced anabolic resistance is overcome with non-nitrogenous supplemental energy or if increased energy as EAA is needed is unclear. We tested the effects of energy as EAA or carbohydrate, combined with an EAA-enriched whey protein, on postexercise MPS (%·h -1 ) and whole-body protein turnover (g protein·240 min -1 ).</p><p><strong>Methods: </strong>Seventeen adults (mean ± SD; age: 26 ± 6 yr, body mass index: 25 ± 3 kg·m -2 ) completed a randomized, parallel study including two 5-d energy conditions (BAL; energy balance; daily energy requirements (DEF), -30% ± 3% energy requirements) separated by ≥7 d. Volunteers consumed EAA-enriched whey with added EAA (+EAA; 304 kcal, 56 g protein, 48 g EAA, 17 g carbohydrate, 2 g fat; n = 8) or added carbohydrate (+CHO; 311 kcal, 34 g protein, 24 g EAA, 40 g carbohydrate, 2 g fat; n = 9) following exercise. MPS and whole-body protein synthesis (PS), breakdown (PB), and net balance (NET; PS-PB) were estimated postexercise with isotope kinetics.</p><p><strong>Results: </strong>MPS rates were greater in +EAA (0.083 ± 0.02) than +CHO (0.059 ± 0.01; P = 0.015) during daily energy requirements, but similar during BAL ( P = 0.45) and across energy conditions within treatments ( P = 0.056). PS rates were greater for +EAA (BAL, 117.9 ± 16.5; daily energy requirements, 110.3 ± 14.8) than +CHO (BAL, 81.6 ± 8.0; daily energy requirements, 83.8 ± 5.9 g protein·240 min -1 ; both P < 0.001) and greater during BAL than daily energy requirements in +EAA ( P = 0.045). PB rates were less in +EAA (8.0 ± 16.5) than +CHO (37.8 ± 7.6 g protein·240 min -1 ; P < 0.001), and NET was greater in +EAA (106.1 ± 6.3) than +CHO (44.8 ± 8.5 g protein·240 min -1 ; P < 0.001).</p><p><strong>Conclusions: </strong>These data suggest that supplementing EAA-enriched whey protein with more energy as EAA, not carbohydrate, maintains postexercise MPS during energy deficit at rates comparable to those observed during energy balance.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"70-80"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142004582","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 Significance of Body Surface Area to Mass Ratio for Thermal Responses to a Standardized Exercise-Heat Stress Test.","authors":"Inbal Akavian, Yoram Epstein, Alexandra Rabotin, Shiraz Peretz, Nisha Charkoudian, Itay Ketko","doi":"10.1249/MSS.0000000000003545","DOIUrl":"10.1249/MSS.0000000000003545","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the significance of body surface area-to-mass ratio (BSA/mass) on the heat-tolerance test (HTT) results. We hypothesized that individuals defined as heat tolerant (HT) would have on average higher BSA/mass compared with heat intolerant (HI) individuals.</p><p><strong>Methods: </strong>A retrospective reanalysis of the HTT results of 517 soldiers (age, 18-38 yr; M/F, 96%:4%), who were tested by the Israel Defense Forces HTT protocol. The criterion for heat tolerance in the current analysis was a rectal temperature (T re ) plateau during the second hour of the test. A logistic regression analysis to evaluate the predictive power of BSA/mass for heat intolerance was performed; the spline model was applied to show the odds for heat intolerance across BSA/mass.</p><p><strong>Results: </strong>In men BSA/mass of HI individuals was lower than HT individuals (248 ± 19 vs 262 ± 18 cm 2 ·kg -1 , P < 0.01, d = 0.76). In women a similar trend was noted but with no statistical significance between HT and HI groups. The odd ratio for heat intolerance for every unit increase in BSA/mass was 0.97 (95% confidence interval, 0.95-0.99). The spline model plateaued above BSA/mass of 270 cm 2 ·kg -1 .</p><p><strong>Conclusions: </strong>The results imply that body-core temperature responses to a standard exercise-heat stress (fixed external work rate and climatic conditions) are influenced by BSA/mass. More specifically, lack of a steady state in T re (indicating heat intolerance) was more likely to occur with every unit decrease in BSA/mass. These findings contribute to a better understanding of the role of body anthropometry in the response to a standard exercise-heat task that might have an implication on clinical decision making about return to duty/play of soldiers, athletes, and others who deemed to be identified as HI.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"88-93"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142109226","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 Load-Velocity Slope Is an Indicator of the Active Drag in All Competitive Swimming Strokes.","authors":"Tomohiro Gonjo, Maria Vitazka, Ingeborg Ljødal, Bjørn Harald Olstad","doi":"10.1249/MSS.0000000000003551","DOIUrl":"10.1249/MSS.0000000000003551","url":null,"abstract":"<p><strong>Introduction: </strong>Active drag in swimming is a critical variable that affects swimmers' performance, as well as the physiological load, but it is challenging for practitioners to assess this variable. This study aimed to assess if the load-velocity profiling method can be used as an indicator of active drag.</p><p><strong>Methods: </strong>A total of 419 swimmers performed three semitethered swimming trials in their speciality among the four competitive strokes with different external loads. Linear regression between external load and swimming velocity, as well as the external load relative to the body mass and swimming velocity, were established. The active drag and drag coefficient of each swimmer were calculated using a velocity perturbation method.</p><p><strong>Results: </strong>There were significant correlations of the active drag with the absolute slope ( correlation coefficient ≥ 0.696, P < 0.001) and relative slope ( correlation coefficient ≥ 0.538, P < 0.001) in all four strokes and both sexes. A multiple regression analysis exhibited that the primary determinant of these relationships was the drag coefficient (semipartial correlation ≥0.422, P < 0.001). The effects of the height and body mass index (BMI) on the relationship between the drag and the absolute slope were small (0.195 ≤ semipartial correlation ≤0.249, P < 0.001), which became either nonsignificant (height: P ≥ 0.282) or trivial (BMI: -0.099 ≤ semipartial correlation ≤ -0.081, P ≤ 0.011) when focusing on the relative slope.</p><p><strong>Conclusions: </strong>These results indicate that the absolute load-velocity slope is a strong indicator of the active drag, and the relative slope is useful when indirectly assessing the drag coefficient.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"115-122"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142290800","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":"Muscle Mitochondrial Capacity Is Impaired Immediately Following Maximal Exercise.","authors":"Callie G Dickinson, Kristin M Mendez, Makayla D Holyfield, Nicholas T Batchelor, Kevin K McCully","doi":"10.1249/MSS.0000000000003533","DOIUrl":"10.1249/MSS.0000000000003533","url":null,"abstract":"<p><strong>Purpose: </strong>This study measured the time course mV̇O 2 max following both maximal and submaximal exercise.</p><p><strong>Methods: </strong>Healthy male and female participants were tested ( n = 12 maximal and n = 8 submaximal exercise). A NIRS device was placed on the left medial gastrocnemius. Participants performed either 1 min of maximal, rapid (~2 Hz), or submaximal (~0.37 Hz) plantar flexion exercise on a custom pneumatic ergometer. mV̇O 2 max was measured before and immediately after exercise. mV̇O 2 max measurements consisted of four incomplete recovery curves of muscle metabolism taken after 30 s of electrical muscle stimulation except in the first post-exercise to be consistent with the use of pre-exercise trial. The four recovery curves were collected 50-, 156-, 260-, and 366-s postexercise, each producing an mV̇O 2 max rate constant.</p><p><strong>Results: </strong>After maximal exercise, muscle acceleration decreased to 52 ± 18% ( P = 0.001) of prevalues. mV̇O 2 max was reduced from the pre-exercise mean at the first post-trial (2.16 ± 0.44 to 1.21 ± 0.52 min -1 , P < 0.001). The fourth trial showed recovery from the first (2.2 ± 0.46 min -1 vs 1.21 ± 0.52 min -1 , P < 0.001) and was not significantly different from pre-exercise values (2.2 ± 0.46 vs 2.16 ± 0.44 min -1 , P = 0.41). No change in acceleration or mV̇O 2 max was seen after submaximal exercise ( P > 0.05).</p><p><strong>Conclusions: </strong>The 56.7% reduction in mV̇O 2 max supports the hypothesis that in young, healthy individuals, a minute of maximal exercise transiently impairs mV̇O 2 max, which then recovers within 6 min. The NIRS method shows promise in tracking time course changes in mV̇O 2 max and warrants further investigation of the transient effects of exercise on mV̇O 2 max.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"173-180"},"PeriodicalIF":4.1,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142004542","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}