Medicine and Science in Sports and Exercise最新文献

{"title":"A Novel Low-Impact Resistance Exercise Program Increases Strength and Balance in Females Irrespective of Menopause Status.","authors":"Erika Svensen, Christopher P Koscien, Nima Alamdari, Benjamin T Wall, Francis B Stephens","doi":"10.1249/MSS.0000000000003586","DOIUrl":"10.1249/MSS.0000000000003586","url":null,"abstract":"<p><strong>Introduction: </strong>The reduction in sex hormone production across the menopause transition is thought to accelerate age-related decline in muscle mass, strength, and stability, increasing the risk of falls and fractures. We aimed to investigate whether a novel low-impact resistance exercise program could improve strength, balance, and body composition and whether any improvement was affected by menopause status.</p><p><strong>Methods: </strong>Seventy healthy, moderately active pre- (PRE; 46.7 ± (SD) 3.2 yr), peri- (PERI; 52.3 ± 2.2 yr), or post- (POST; 57.0 ± 2.5 yr) menopausal females, not taking hormone replacement therapy (HRT), were randomized to continue habitual physical activity (CON; n = 25) or complete a supervised resistance exercise program 4 d·wk -1 for 12 wk (EXC; n = 45). Strength at the hip and shoulder (isokinetic dynamometer), dynamic balance (Y-balance), flexibility (sit-and-reach and back-scratch), muscle thickness (rectus femoris, vastus intermedius (VI), and medial deltoid), and lean and % body fat (dual-energy x-ray absorptiometry) were measured before and after training.</p><p><strong>Results: </strong>Hip abduction and flexion peak torque (19% ± 48% and 20% ± 17%, respectively; P < 0.05), posterolateral and posteromedial balance (12% ± 15% and 13% ± 15%, respectively; P < 0.001), flexibility (21% ± 36%, P < 0.001), VI thickness (12% ± 19%, P = 0.032), and lean mass (2% ± 2%, P = 0.007) all increased over 12 wk in EXC, but not CON, with no difference in response between PRE, PERI, and POST. The changes in shoulder strength and body mass over 12 wk were not different between CON and EXC.</p><p><strong>Conclusions: </strong>This is the first study to demonstrate that the decline in sex hormones and an increase in age across the menopause transition do not affect the ability of lower limb (hip) strength and balance to adapt to a low-impact resistance exercise training program in females not taking HRT.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"501-513"},"PeriodicalIF":4.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11801421/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduced Lower Body Muscular Strength and Endurance among Adult Survivors of Childhood Cancer.","authors":"Tomáš Sláma, Carina Nigg, Reto D Kurmann, Gabriela M Kuster, Nana K Poku, Eva Scheler, Claudia E Kuehni, Nicolas X VON DER Weid, Christina Schindera","doi":"10.1249/MSS.0000000000003593","DOIUrl":"10.1249/MSS.0000000000003593","url":null,"abstract":"<p><strong>Introduction: </strong>Impaired physical fitness is a possible late effect among adult survivors of childhood cancer (ASCC). Our study describes lower body muscular strength and endurance among ASCC using the 1-min sit-to-stand (1-min STS) test, compares them with the general population, identifies risk factors, and describes changes over time.</p><p><strong>Methods: </strong>In a prospective multicenter cohort study, we invited ASCC ≥18 yr of age at study who were diagnosed between ages 0 and 20 yr, treated in five pediatric oncology centers across Switzerland from 1976 to 2017, and survived ≥5 yr for a 1-min STS test. We collected information about lifestyle, medical history, and previous cancer treatment. Using population-based Swiss reference values, we calculated age- and sex-adjusted z -scores for 1-min STS performance and assessed the association between risk factors and 1-min STS test using multivariable linear regression. We fitted a multilevel linear model to describe the longitudinal course of 1-min STS performance.</p><p><strong>Results: </strong>We included 338 CCS of 1048 invited ASCC (participation rate 32%) with a median age at study of 34 yr (interquartile range, 26-41 yr). Compared with the general population, mean 1-min STS z -score was half a standard deviation lower (-0.52; 95% confidence interval (CI), -0.64 to -0.40). Obesity ( B = -0.56; 95% CI, -0.97 to -0.16), cumulative cisplatin dose ( B = -0.12; 95% CI, -0.21 to -0.02), and cumulative cranial radiotherapy dose ( B = -0.10; 95% CI, -0.19 to -0.01) were associated with reduced 1-min STS performance. There was no change in 1-min STS z -scores over time ( B = 0.02; 95% CI, -0.05 to 0.09).</p><p><strong>Conclusions: </strong>We found evidence for reduced lower body strength and endurance among ASCC, suggesting the need for counseling and effective training and rehabilitation programs for maintaining daily functioning, improving cardiovascular health, and reducing morbidity for ASCC.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"563-571"},"PeriodicalIF":4.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11801469/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142984073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Resistance and Speed on Electromyographic Activity of Thigh and Gluteal Muscles in Elite Athletes throughout Resisted Sprint Running.","authors":"Robin Macchi, András Hegyi, Caroline Giroux, Giuseppe Rabita, Antoine Nordez, Enzo Hollville, Antoine Couturier, Charly Fornasier-Santos, Jean Slawinski, Jean-Benoit Morin, Lilian Lacourpaille, Gaël Guilhem","doi":"10.1249/MSS.0000000000003689","DOIUrl":"10.1249/MSS.0000000000003689","url":null,"abstract":"<p><strong>Purpose: </strong>The application of horizontal resistance is key in sprint training to modulate velocity and promote adaptations. However, the interaction between velocity and resistance on muscle excitation remains insufficiently studied. This study assessed the electromyographic (EMG) activity of thigh and gluteal muscles in response to varying velocity and resistance during sprinting.</p><p><strong>Methods: </strong>Thirty-seven elite athletes (27 females and 10 males) performed two trials under three conditions: a 40-meter maximal sprint without resistance and two resisted sprints applied by a robotic device with resistive forces equivalent to 25% and 75% of body mass in a sled condition. EMG activity was recorded from eight muscles in the quadriceps, hamstrings, and gluteal muscle groups for both lower limbs. Generalized mixed models were used to analyze average EMG changes with increasing velocity as a function of resistance. Statistical parametric mapping was used to assess the changes within the stance and swing phases as a function of sprint phase and resistance.</p><p><strong>Results: </strong>Hamstring EMG activity increased with increasing velocity (+17.9% in stance phase without resistance) and decreased as resistance increased, with opposite effects observed in quadriceps muscles. Higher gluteal EMG activity was found during the late swing phase with increasing velocity and decreasing resistance. The biceps femoris long head exhibited the largest EMG increase with velocity (+23% in the stance phase) among hamstrings, while the semitendinosus showed the highest increase with reduced resistance (+27% in the stance phase).</p><p><strong>Conclusions: </strong>External resistance and running speed influence thigh muscle activity differently, even within the same muscle group, likely due to distinct muscle architecture and function. These insights should be considered when designing sprint training programs to target specific muscle groups, avoid muscle overloading, and account for inter-individual differences to optimize performance and reduce injury risk.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527923","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":"Strength Training Improves Running Economy Durability and Fatigued High-Intensity Performance in Well-Trained Male Runners: A Randomized Control Trial.","authors":"Michele Zanini, Jonathan P Folland, Han Wu, Richard C Blagrove","doi":"10.1249/MSS.0000000000003685","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003685","url":null,"abstract":"<p><strong>Introduction: </strong>Strength training improves running economy (RE) in a non-fatigued state and performance after prolonged exercise at moderate intensity. However, it is unknown if strength training improves RE durability at marathon race intensity, or high-intensity performance akin to the final stages of a competitive race. This study quantified the effect of a supplementary 10-week strength training program on RE throughout 90 min of running in the heavy-intensity domain, and subsequent fatigued performance in runners.</p><p><strong>Methods: </strong>Twenty-eight well-trained male runners (maximal oxygen uptake (V̇O2max) 58.6 ml·kg-1·min-1; 10 km 39:02 mm:ss) were performance-matched and randomly assigned to a habitual running-only control (E; n = 14) or supplementary strength training group (E + S; n = 14) that performed maximal strength and plyometric training twice weekly for 10 weeks. Before the training, participants performed a 90 min run at 10% Δ between lactate threshold 1 and 2 (13.1 ± 1.4 km/h, 79.7% V̇O2max). RE, quantified as oxygen cost (ml·kg-1·km-1), was recorded at 15 min intervals during the run, immediately thereafter, participants ran a time to exhaustion (TTE) at 95% pre-test V̇O2max (16.1 ± 1.6 km/h). The 90 min run and TTE were repeated after the training intervention.</p><p><strong>Results: </strong>A large interaction effect of training x group x run time was found for RE (p = 0.003, ηp2 = 0.13), with E + S improving vs E at 90 min (-2.1% vs +0.6; p = 0.04). For TTE, a large group x training interaction effect was detected (p = 0.004, ηp2 = 0.28), changing by +35% in E + S and -8% in E.</p><p><strong>Conclusions: </strong>This study demonstrated that adding strength and plyometrics training to a programme of endurance running improved RE durability and substantially increased high-intensity TTE at the end of a 90 min run in the heavy intensity domain in well-trained male runners.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143523760","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":"Fat Oxidation Rates during Exercise in Pre-Pubertal Children: The Role of Obesity, Fitness and Lean Mass.","authors":"Irene Rodríguez-Gómez, María Martín-García, Luis M Alegre, Beatriz García-Cuartero, Amparo González-Vergaz, Atilano Carcavilla, Ángel Aragonés, Ignacio Ara","doi":"10.1249/MSS.0000000000003690","DOIUrl":"10.1249/MSS.0000000000003690","url":null,"abstract":"<p><strong>Purpose: </strong>To determine fat oxidation values during a graded cyclo-ergometer exercise in pre-pubertal children considering cardiorespiratory fitness (CRF) and body size based on obesity status and sex. Moreover, to elucidate whether body mass index (BMI) or fat accumulation mediate the relationship between CRF and fat oxidation.</p><p><strong>Methods: </strong>We evaluated 118 pre-pubertal children (59 girls) aged 11.5 ± 2.0 yr (Tanner ≤II). Body composition was assessed using dual-energy X-ray absorptiometry and anthropometry, CRF (peak oxygen uptake -VO 2peak ) and fat oxidation rates were determined during a graded cycling test.</p><p><strong>Results: </strong>In absolute values, obese pre-pubertal children displayed higher maximal fat oxidation (MFO) compared to overweight and normal-weight counterparts ( p = 0.006). However, after adjusting by CRF the difference in MFO disappeared ( p = 0.104). When MFO was expressed with respect to body size and adjusted by CRF, it was significantly greater in normal-weight children ( p = <0.001). Similar results were found in boys and girls. Furthermore, fat accumulation and BMI acted as mediators in the relationship between CRF and fat oxidation, explained a 38% of the variance.</p><p><strong>Conclusions: </strong>Fat oxidation levels are comparable among pre-pubertal children, regardless of obesity status, upon CRF adjustment. Nevertheless, when contextualized within body size, obese and overweight children demonstrated reduced fat oxidation capacity compared to their normal-weight peers during exercise and with no sex-related differences. Furthermore, fat mass seems to be a mediator factor between CRF and fat oxidation.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143527926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Protocol to Establish Exercise Intensity Domains for Aerobic Exercise Training in Coronary Artery Disease.","authors":"Robin Faricier, Randi R Keltz, Tim Hartley, Nathan Mackay, Juan M Murias, Ashlay A Huitema, Robert S McKelvie, Neville G Suskin, Daniel A Keir","doi":"10.1249/MSS.0000000000003684","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003684","url":null,"abstract":"<p><strong>Methods: </strong>The SRS protocol included in series: 6-min of cycling at 25-40 W, a ramp-incremental test until task failure (5-15 W·min-1), and, after recovery, 12-min of cycling at ~50-60% of peak ramp PO. On separate days, patients performed three domain-specific constant-PO exercises at 80%θLT (moderate-intensity, MOD), 70% of the difference between θLT and RCP (heavy-intensity, HVY), and 115%RCP (severe-intensity, SEV). Measured V̇O2 for: MOD and HVY were compared to those predicted using either SRS-corrected or uncorrected approaches; and, for SEV, were compared to peak ramp V̇O2.</p><p><strong>Results: </strong>The POs for MOD, HVY, and SEV were 53 ± 27 W, 96 ± 50 W, and 116 ± 56 W, respectively, eliciting V̇O2 of 1012 ± 362 mL·min-1, 1541 ± 638 mL·min-1, and 1944 ± 744 mL·min-1. The SRS-corrected predictions did not differ from measured V̇O2 for MOD (-25 ± 61 mL·min-1; p = 0.201) or HVY (-40 ± 89 mL·min-1; p = 0.208), whereas uncorrected predictions underestimated V̇O2 by -128 ± 72 mL·min-1 (p = 0.002) and -199 ± 99 mL·min-1 (p = 0.001) in MOD and HVY, respectively. Peak V̇O2 from SEV did not differ from the ramp (1906 ± 766 mL·min-1; p = 0.759).</p><p><strong>Conclusions: </strong>In CAD, the V̇O2-to-PO relationship from incremental exercise must be corrected to prescribe constant intensity training. The SRS protocol is an accurate approach to ensure prescriptive accuracy.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143502274","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":"Advanced Footwear Technology, but not Acute Ingestion of a Ketone Monoester, Improves Running Economy in Middle- and Long-Distance Runners.","authors":"Aidan J Brady, Megan B Moynagh, Simon Devenney, Brendan Egan","doi":"10.1249/MSS.0000000000003682","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003682","url":null,"abstract":"<p><strong>Purpose: </strong>This study examined the separate and combined effects of advanced footwear technology (AFT) and acute ingestion of a ketone monoester on running economy (RE), time-to-exhaustion (TTE), and other metabolic and cardiorespiratory parameters.</p><p><strong>Methods: </strong>In a four-condition, placebo-controlled, randomized crossover design, 18 middle- and long-distance runners (male/female, 10/8, V̇O2peak: 59.4 ± 7.2 mL·kg-1·min-1) completed five 8 min stages of submaximal running (male: 10-14 km·h-1; female: 9-13 km·h-1) on a motorized treadmill, immediately followed by a ramp test to volitional exhaustion. Participants consumed 500 mL of either a 10% carbohydrate solution (CHO) or 500 mg·kg-1 body mass of an (R)-3-hydroxybutyl (R)-3-hydroxybutyrate ketone monoester with flavored water (KME) 20 min before exercise, and an additional 300 mL of the 10% carbohydrate solution or 250 mg·kg-1 body mass of KME during exercise, while wearing either Nike Pegasus Turbo (PEG) or Nike ZoomX Vaporfly Next% 3 (VAP) running shoes. The four randomized conditions were PEG+CHO, PEG+KME, VAP + CHO, and VAP + KME.</p><p><strong>Results: </strong>RE was significantly improved during the third and fourth submaximal running stages in VAP + CHO and VAP + KME compared to PEG+CHO and PEG+KME (all P < 0.05; ES = 0.53-0.84). RE was also improved during the fifth submaximal running stage in VAP + KME compared to PEG+CHO, and in VAP + CHO and VAP + KME compared to PEG+KME (all P < 0.05; ES = 0.56-0.66). No differences in RE were found between CHO and KME conditions. TTE was significantly longer in VAP + CHO (381 ± 125 s) than PEG+CHO (356 ± 140 s; ES = 0.18, P = 0.023) and PEG+KME (329 ± 131 s, ES = 0.40, P < 0.001) and in VAP + KME (375 ± 125 s) than PEG+KME (ES = 0.35, P < 0.001).</p><p><strong>Conclusions: </strong>AFT, but not the acute ingestion of a ketone monoester, improved the RE of trained male and female middle- and long-distance runners at submaximal running speeds.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143502275","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":"Solving Heat Stress in Sport: Intermittent Cold Air Exposure Mitigates Deterioration of the Autonomic Nervous System in American Football Athletes.","authors":"Eric Renaghan, Michael J Wishon, Harrison L Wittels, Dustin Hecocks, Peter J Galasso, Tom Ren, Samantha M McDonald, Luis A Feigenbaum, S H Wittels","doi":"10.1249/MSS.0000000000003686","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003686","url":null,"abstract":"<p><strong>Objectives: </strong>Cooling interventions mitigating heat-related declines in autonomic nervous system (ANS) function are understudied in American football.</p><p><strong>Methods: </strong>This study exposed fifty, collegiate male athletes during their 2023 season to two bouts of cold air via air-conditioning prior to (60 mins) and during (5 min) training sessions in a hot and humid climate. Armband monitors, (Warfighter MonitorTM, Tiger Tech Solutions, Inc., Miami, FL, USA), were used to continuously measure core temperature (°C) during training and baseline heart rate (HR), HR recovery and HR variability (HRV) 24 hours post training. Two HRV time-domain indices were estimated: root mean square of the standard deviation of the NN interval (rMSSD) and the standard deviation of the NN interval (SDNN). These data (2023) were then compared to data collected throughout the previous season (2022) during which players were not provided a cold-air intervention. As such, the 2022 cohort served as a \"control\" group.</p><p><strong>Results: </strong>Linear regression models no statistically significant associations at the following core temperature thresholds: ≥ 37.0 °C (baseline HR: p = 0.74; HR recovery: p = 0.71, rMSSD: p = 0.74; SDNN: p = 0.78), ≥ 38.0 °C baseline HR: p = 0.74; HR Recovery: p = 0.74; rMSSD: p = 0.68 and SDNN: p = 0.89) and ≥ 39.0 °C: baseline HR: p = 0.75; HR Recovery: p = 0.82; rMSSD: p = 0.78 and SDNN: p = 0.83). Compared to the 2022 season, the athletes spent considerably less time training under the higher core temperature thresholds (≥ 38 °C: 19.5 min vs 9.7 min; ≥ 39 °C: 10.5 min vs 0.9 min), respectively, despite longer overall training duration, (161.1 min vs 187.4 min).</p><p><strong>Conclusions: </strong>Our findings suggest that incorporating bouts of cold air exposure when training in high heat and humidity may mitigate the established heat-related deterioration in ANS function.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143502278","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-Based Differences in Representation of Top Youth Athletes.","authors":"Jessica J James, Sandra K Hunter, Elizabeth P Bueckers, Michael J Joyner, Jonathon W Senefeld","doi":"10.1249/MSS.0000000000003681","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003681","url":null,"abstract":"<p><strong>Objectives: </strong>Among overall top performances of youth track and swimming athletes, we aimed to determine: 1) the proportional number of male compared to female athletes represented and 2) at what age females are no longer represented.</p><p><strong>Methods: </strong>Finishing times and sex of the top 10 and top 100 performances of youth runners and swimmers between 5-18 years were abstracted from online US-based databases for four running (100 m-800 m) and six freestyle swimming events (50 m-1500 m).</p><p><strong>Results: </strong>Males represented a greater proportion of the top 10 performances starting at 7 years in running (P = 0.023) and 12 years in swimming (P = 0.023) (averaged across events). Males represented a greater proportion of the top 100 performances starting at 6 years in running (P < 0.001) and 7 years in swimming (P < 0.001) (averaged across events). Females were no longer represented within the top 10 performances starting at ~12 years in running and ~ 13 years in swimming and no longer represented within the top 100 starting at ~14 years in running and ~ 15 years in swimming.</p><p><strong>Conclusions: </strong>In elite youth athletes, there was a greater proportion (representation) of males within the top 100 running and swimming performances beginning between ages 6 and 7, with females no longer represented between ages 14 and 15. Our findings suggest males are more likely to be represented \"on the podium\" in open sporting events (not categorized by sex) than females starting at age 6.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143502277","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":"Lung Volume-Dependent Decrease in Projected Frontal Area Contributes to Reducing Active Drag in Front Crawl.","authors":"Sohei Washino, Akihiko Murai, Hirotoshi Mankyu, Hiroaki Kanehisa, Yasuhide Yoshitake","doi":"10.1249/MSS.0000000000003683","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003683","url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to investigate whether a lung volume-dependent decrease in the projected frontal area (PFA) contributes to reducing active drag in the front crawl.</p><p><strong>Methods: </strong>Twelve competitive male swimmers performed a 15 m front crawl at 1.20 m·s-1 while sustaining one of three lung volume levels: maximal inspiration (INSP), maximal expiration (EXP), or intermediate (MID). The three-dimensional positions of the reflective markers attached to the swimmers' bodies were measured using an underwater motion-capture system. Based on the body shape obtained from the photogenic body scanner, an individual digital human model was created using model vertices color-coded into eight body segments. The time series of the volumetric swimming motion was reconstructed using the individual digital human model and motion capture data. The PFA of each body segment was calculated using image processing. The pressure drag index (PDI), defined as the value excluding the drag coefficient while simultaneously considering the PFA and horizontal velocity, was calculated for each body segment.</p><p><strong>Results: </strong>There were significant interactions between lung volume and body segment on PFA and PDI (both p < 0.001). Specifically, the PFA and PDI of the head segment were smaller in INSP than in EXP (p ≤ 0.046); in addition, the PFA and PDI of the trunk and femur segments were smaller in INSP and MID than in EXP (p ≤ 0.003).</p><p><strong>Conclusions: </strong>These findings suggest that the decrease in PFA caused by the increase in lung volume directly contributes to reducing active drag.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143492715","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}