Medicine and Science in Sports and Exercise最新文献

{"title":"Graded Walking Energetics under Cold Strain.","authors":"David P Looney, Erica A Schafer, Christopher L Chapman, J Luke Pryor, Brandon M Roberts, Jesse A Stein, Karl E Friedl, Adam W Potter","doi":"10.1249/MSS.0000000000003664","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003664","url":null,"abstract":"<p><strong>Introduction: </strong>Although research supports selecting steeper routes to minimize metabolic rate (Ṁ) in mountain racers, the \"steeper is cheaper\" strategy has yet to be confirmed for slower, more typical graded walking speeds under cold stress.</p><p><strong>Purpose: </strong>Confirm whether \"steeper is cheaper\" is true for typical graded walking speeds in individuals exposed to incremental cold stress.</p><p><strong>Methods: </strong>Fourteen healthy, military-age adults (age, 24 ± 6 years; height, 1.72 ± 0.08 m; body mass, 72 ± 16 kg) completed four 20-min treadmill walks in three ambient temperatures (20, 10, and 0 °C) in light clothing (i.e., shorts, t-shirt, light gloves). Each walk involved five stages at incremental vertical speeds (0.00, 1.93, 3.86, 5.79, 7.79 m·min-1) but variable treadmill speeds (0.54, 0.72, 1.07 m·s-1). To verify the \"steeper is cheaper\" strategy, we compared Ṁ between treadmill speeds at matched vertical speeds in each temperature. We also tested if the 90% confidence interval around the mean percent paired difference between Load Carriage Decision Aid (LCDA) metabolic model predictions and measured Ṁ was within ±10%.</p><p><strong>Results: </strong>Ṁ was significantly higher for the faster treadmill speed at matched vertical speeds in all but two comparisons at 20 °C, all but two comparisons at 10 °C, and all comparisons at 0 °C (p < 0.05). LCDA metabolic model predictions were statistically equivalent to measured Ṁ during graded walking at 20 °C (90% CI, -3.1, 0.6%) and 10 °C (-7.8, -2.6%) but not 0 °C (-16.2, -9.5%).</p><p><strong>Conclusions: </strong>Route planners should recommend steeper but shorter routes to minimize Ṁ in individuals that walk in temperate-to-cold environments. The LCDA metabolic model provides accurate Ṁ predictions in lightly dressed individuals in temperatures down to 10 °C, but users should expect underestimated Ṁ in 0 °C or colder.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143080548","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":"Leisure Physical Activity, Sedentary Behavior, and Cardiovascular Health 2-7 Years after Pregnancy in the nuMoM2b HHS Cohort.","authors":"Bethany Barone Gibbs, Sarah Modlin, Noel Bairey Merz, David M Haas, Sadiya S Khan, Abbi Lane, Rebecca B McNeil, Jasmina Varagic, Kimberly Huber, Ligia Vasquez-Huot, Janet M Catov","doi":"10.1249/MSS.0000000000003660","DOIUrl":"10.1249/MSS.0000000000003660","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate whether higher moderate-to-vigorous intensity physical activity (MVPA) and lower sedentary behavior (SB) are related to better cardiovascular health (CVH) following pregnancy.</p><p><strong>Methods: </strong>In the nuMoM2b Heart Health Study (HHS) cohort, Life's Essential 8 health factors (BMI, blood pressure, glucose, and lipid) were assessed in the first trimester of pregnancy and 2-7 years later (n = 3,985). The four health factors were scored with Life's Essential 8 criteria (0 = poorest; 100 = ideal) and averaged to calculate a CVH health factor score (CVHhf). Self-reported leisure MVPA and SB were assessed at follow-up. Linear regression evaluated associations of MVPA levels and SB quartiles with follow-up CVHhf after adjustment for first trimester CVHhf and covariates. Analyses were repeated after stratification by history of hypertensive disorders of pregnancy (HDP) or gestational diabetes (GDM).</p><p><strong>Results: </strong>Over follow-up (mean 3.2 years after delivery), CVHhf declined from 85.6 to 81.6 points (-4.0 points, p < 0.001). The decline was greatest in lipid (-8.4 points, p < 0.001) and BMI scores (-5.6 points, p < 0.001). Healthier activity profiles (higher MVPA level and lower SB quartile) were each associated with higher CVHhf at follow-up: 0.7 points higher per level of MVPA, p < 0.001; 0.5 points lower per quartile of SB, p = 0.0042. Higher MVPA level associated with healthier BMI, glucose, and lipid scores; lower SB quartile associated with healthier BMI and blood pressure scores (p < 0.05). Although HDP/GDM history was associated with lower CVHhf, patterns of CVHhf across healthier leisure MVPA levels and SB quartiles were similar in those with and without HDP or GDM.</p><p><strong>Conclusions: </strong>Higher MVPA and lower SB during leisure could help to maintain CVH health factors in the years following pregnancy, including among those who experienced HDP or GDM.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143080615","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":"Genome Wide Association Study on Muscle Stiffness Identified Novel Locus for Predisposition to Muscle Strain Injury.","authors":"Eri Miyamoto-Mikami, Hirofumi Zempo, Hiroshi Kumagai, Kosuke Hirata, Mizuki Takaragawa, Toshinori Yoshihara, Mizuho Fuku, Naoki Kikuchi, Nobuhiro Kamiya, Naokazu Miyamoto, Noriyuki Fuku","doi":"10.1249/MSS.0000000000003661","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003661","url":null,"abstract":"<p><strong>Purpose: </strong>We aimed to screen the entire genome for genetic variants associated with passive muscle stiffness, which has been suggested as a risk factor for muscle strain injury.</p><p><strong>Methods: </strong>This genome-wide association study (GWAS) on passive muscle stiffness included 350 physically active young Japanese individuals. Three hamstring constituents were measured using ultrasound shear wave elastography. Skeletal muscle transcriptomes were compared across the genotypes of GWAS-identified variants in 48 healthy Japanese individuals. Association between GWAS-identified variants and history of muscle strain injury were examined in 1,428 Japanese athletes.</p><p><strong>Results: </strong>Two loci on chromosome 11 demonstrated a genome-wide significant association with passive muscle stiffness of the biceps femoris long head (rs12807854 T/C: P = 5.19 × 10-10, rs78405694 T/C: P = 2.09 × 10-8; linear regression analysis adjusted for sex, age, and stretching exercise habits). Skeletal muscle RNA sequencing revealed significantly elevated expression of extracellular matrix-related genes in muscles carrying stiffness-increasing alleles of these variants. Among athletes, rs12807854 T/C was significantly associated with a history of muscle strain injury (P = 0.0254; logistic regression analysis adjusted for age, sex, competitive level, and main sport). Carriers of the C allele, associated with increased muscle stiffness, exhibited a heightened risk of muscle strain injury (odds ratio: 1.62; 95% confidence interval: 1.06-2.47 per C allele increase). In contrast, rs78405694 did not show a significant association with muscle strain injury in this population.</p><p><strong>Conclusions: </strong>A novel locus associated with passive muscle stiffness and muscle strain injury was identified. Elucidating the detailed mechanisms linking the identified locus to passive muscle stiffness may lead to the development of new strategies to prevent muscle strain injuries.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143188880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Sports Bras and Breast Volume on Pulmonary System and Respiratory Symptom Responses to Exercise in Healthy Females.","authors":"Camilla R Illidi, Dennis Jensen","doi":"10.1249/MSS.0000000000003561","DOIUrl":"10.1249/MSS.0000000000003561","url":null,"abstract":"<p><strong>Purpose: </strong>This study assessed the individual and combined effects of sports bras and breast volume on pulmonary system and respiratory symptom responses to exercise in recreationally active females.</p><p><strong>Methods: </strong>Twenty-three healthy females (18-27 yr; bra sizes 32B-36DDD) were divided into small and large breast volume groups (SBV and LBV, respectively) around median volume (324 mL; mean ± SD SBV: 284 ± 38 mL vs LBV: 560 ± 97 mL; P < 0.001, g = 3.84). Participants completed three 5-min bouts of constant-load cycle exercise at 30%, 60%, and 90% of their peak power output while wearing a high-support sports bra, low-support sports bralette, or their personal (self-selected) sports bra in randomized order. Measurements included ventilation, breathing pattern, respiratory pressures, diaphragm electromyogram (EMGdi), and ratings of perceived exertion (RPE), breathlessness (intensity and unpleasantness), and chest tightness due to bra.</p><p><strong>Results: </strong>Compared with low-support and personal sports bras, the high-support sports bra evoked stronger sensations of restricted breathing and chest tightness (\"slight\" to \"moderate\" restriction in n = 7 (30%) vs n = 1 (4%) in low-support and personal bras; P = 0.014). There was, however, no evidence of greater concomitant inspiratory constraints, EMGdi, or inspiratory muscle pressure generation in either bra (all P > 0.05). Notably, LBV compared with SBV, participants reported greater RPE ( P = 0.037, ηp2 = 0.20), breathlessness intensity ( P = 0.039, ηp2 = 0.20), and unpleasantness ( P = 0.041; ηp2 = 0.19), which, in the setting of comparable pulmonary system responses to exercise, was likely driven by stronger perceived chest tightness and/or bra awareness in LBV participants.</p><p><strong>Conclusions: </strong>Despite evoking mild-to-moderately severe chest tightness due to bra during exercise, correctly fitted sports bras, whether low- or high-support, do not impose a physiological burden to the respiratory system and its response to mild-to-heavy intensity exercise in otherwise healthy females.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"305-316"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142290794","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":"Theoretical Behavior Substitutions during the 24-h Day in Pregnancy and Infant Growth Outcomes.","authors":"Sylvia E Badon, Assiamira Ferrara, Kelley Pettee Gabriel, Erin E Dooley, Charles P Quesenberry, Lyndsay A Avalos, Monique M Hedderson","doi":"10.1249/MSS.0000000000003566","DOIUrl":"10.1249/MSS.0000000000003566","url":null,"abstract":"<p><strong>Purpose: </strong>The purpose of this study is to assess associations of theoretically reallocating time from sleep, sedentary behavior, or light-intensity physical activity (LPA) to moderate/vigorous-intensity physical activity (MVPA) during pregnancy with infant growth outcomes.</p><p><strong>Methods: </strong>We used data from a cohort of pregnant individuals with overweight or obesity ( n = 116). At 9 to 15 and 30 to 36 wk of gestation, waking movement was measured using wrist-worn accelerometers and sleep duration was self-reported. Outcomes were obtained from delivery electronic health records (birth) and study visits (12 months). We used compositional isotemporal substitution models.</p><p><strong>Results: </strong>In early pregnancy, reallocating 10 min of sleep, sedentary behavior, or LPA to MVPA was associated with 20% (relative risk [RR] = 0.80; 95% CI, 0.75-0.85), 21% (RR = 0.79; 95% CI, 0.75-0.84), and 25% (RR = 0.75; 95% CI, 0.70-0.81) lower risk of large-for-gestational age (LGA) birthweight, respectively, and 17% (RR = 0.83; 95% CI, 0.75-0.91), 18% (RR = 0.82; 95% CI, 0.75-0.91), and 22% (RR = 0.78; 95% CI, 0.70-0.88) lower risk of rapid infant growth (birth to 12 months), respectively. In late pregnancy, reallocating 10 min to MVPA was associated with 18% to 22% lower risk of LGA birthweight, but was not associated with rapid infant growth. Reallocating time to MVPA in early or late pregnancy was not associated with high newborn body fat percentage.</p><p><strong>Conclusions: </strong>Our findings suggest beneficial associations of theoretically reallocating time from sleep, sedentary behavior, or LPA to MVPA, especially during early pregnancy, for reducing LGA birthweight and rapid infant growth.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"337-344"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142349735","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":"Off- and On-Bike Resistance Training in Cyclists: A Randomized Controlled Trial.","authors":"David Barranco-Gil, Alejandro Hernández-Belmonte, Víctor Rodríguez-Rielves, Jon Iriberri, Alejandro Martínez-Cava, Ángel Buendía-Romero, Lidia B Alejo, Francisco Franco-Lopez, Iván R Sanchez-Redondo, Raúl DE Pablos, Alejandro Lucia, Pedro L Valenzuela, Jesús G Pallares","doi":"10.1249/MSS.0000000000003556","DOIUrl":"10.1249/MSS.0000000000003556","url":null,"abstract":"<p><strong>Purpose: </strong>This study compared the effects of off- and on-bike resistance training (RT) on endurance cycling performance as well as muscle strength, power, and structure.</p><p><strong>Methods: </strong>Well-trained male cyclists were randomly assigned to incorporate two sessions/week of off-bike (full squats, n = 12) or on-bike (all-out efforts performed against very high resistances and thus at very low cadences, n = 12) RT during 10 wk, with all RT-related variables (number of sessions, sets, and repetitions, duration of recovery periods, and relative loads [70% of one-repetition maximum]) matched between the two groups. A third, control group ( n = 13), did not receive any RT stimulus, but all groups completed a cycling training regime of the same volume and intensity. Outcomes included maximum oxygen uptake (V̇O 2max ), off-bike muscle strength (full squat) and on-bike (\"pedaling\") muscle strength, and peak power capacity (Wingate test), dual-energy X-ray absorptiometry-determined body composition (muscle/fat mass), and muscle structure (cross-sectional area, pennation angle).</p><p><strong>Results: </strong>No significant within/between-group effect was found for V̇O 2max . Both the off-bike (mean Δ = 2.6%-5.8%) and on-bike (4.5%-7.3%) RT groups increased squat and pedaling-specific strength parameters after the intervention compared with the control group (-5.8% to -3.9%) ( P < 0.05) with no significant differences between them. The two RT groups also increased Wingate performance (4.1% and 4.3%, respectively, vs -4.9% in the control group, P ≤ 0.018), with similar results for muscle cross-sectional area (2.5% and 2.2%, vs -2.3% in the control group, P ≤ 0.008). No significant within/between-group effect was found for body composition.</p><p><strong>Conclusions: </strong>The new proposed on-bike RT could be an effective alternative to conventional off-bike RT training for improving overall and pedaling-specific muscle strength, power, and muscle mass.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"296-304"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142133101","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":"Exercise, Sports Participation, and Quality of Life in Young Patients with Heritable Thoracic Aortic Disease.","authors":"Theodore J Millette, Randy K Ramcharitar, Oliver J Monfredi, Matthew J Thomas, Mark R Conaway, Peter N Dean","doi":"10.1249/MSS.0000000000003570","DOIUrl":"10.1249/MSS.0000000000003570","url":null,"abstract":"<p><strong>Introduction: </strong>Patients with heritable thoracic aortic disease (HTAD) are often restricted from sports and certain types of exercise. This study was designed to investigate the effect of lifetime exercise exposure and competitive sports participation on quality of life (QOL) in patients 15-35 yr old with syndromic (Marfan syndrome, Loeys-Dietz syndrome, and vascular Ehlers-Danlos syndrome) and nonsyndromic HTAD (nsHTAD).</p><p><strong>Methods: </strong>This cross-sectional study used questionnaires to assess lifetime exercise exposure and utilized the PedsQL QOL Inventory. We developed an exercise exposure score (EES) to quantify lifetime exercise exposure. Questionnaires were completed via telephone with complimentary medical record review.</p><p><strong>Results: </strong>Forty patients were enrolled. Mean age was 26 yr. The diagnosis was Marfan syndrome in 83%. Despite 88% of patients being restricted by their provider, 65% reported competitive sports participation and 93% reported recreational exercise. Participants with an EES greater than the median had significantly better total QOL scores compared with those below the median (78 vs 65, P = 0.03). There were significant positive correlations between current frequency of exercise and psychosocial QOL (slope = 3.9, 95% CI = 1.2-6.6, P = 0.005), physical QOL (slope = 8.1, 95% CI = 4.1-12, P < 0.001), and total QOL score (slope = 6.0, 95% CI = 3.1-9.0, P < 0.001). We found no difference in aortic size or need for surgical intervention between those above and below the median EES, or between those who did and did not participate in competitive sports.</p><p><strong>Conclusions: </strong>Despite exercise restrictions, young HTAD patients are physically active. Increased lifetime exercise and current physical activity levels were associated with improved QOL in HTAD patients.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"260-266"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142349723","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":"Mitochondrial Influence on Performance Fatigability: Considering Sex Variability.","authors":"Gaia Giuriato, Chiara Barbi, Fabio Giuseppe Laginestra, Mehran Emadi Andani, Thomas Favaretto, Camilla Martignon, Anna Pedrinolla, Gianluca Vernillo, Tatiana Moro, Martino Franchi, Maria Grazia Romanelli, Federico Schena, Massimo Venturelli","doi":"10.1249/MSS.0000000000003558","DOIUrl":"10.1249/MSS.0000000000003558","url":null,"abstract":"<p><strong>Objective: </strong>Existing literature indicates that females generally demonstrate higher fatigue resistance than males during isometric contractions. However, when it comes to single-limb dynamic exercises, the intricate interplay between performance fatigability (PF), cardiovascular responses, and muscle metabolism in relation to sex differences remains underexplored.</p><p><strong>Purpose: </strong>This study investigates how sex affects the relationship between muscle oxidative characteristics and the development of PF during dynamic single-leg exercise.</p><p><strong>Methods: </strong>Twenty-four young healthy participants (12 males vs 12 females) performed a constant-load single-leg knee extension task (85% peak power output; 60 rpm) to exhaustion (TTE). Neuromuscular assessments via transcranial magnetic and peripheral stimulations were conducted before and after exercise to evaluate central and peripheral factors of PF. Vastus lateralis muscle biopsies were obtained for mitochondrial respiration and immunohistochemistry analyses.</p><p><strong>Results: </strong>Participants performed similar total work (28 ± 7 vs 27 ± 14 kJ, P = 0.81) and TTE (371 ± 139 vs 377 ± 158 s, P = 0.98); after the TTE, females' maximal isometric voluntary contraction (MVIC: -36% ± 13% vs -24% ± 9%, P = 0.006) and resting twitch (RT; -65% ± 9% vs -40% ± 24%, P = 0.004) force declined less. No differences were observed in supraspinal neuromuscular factors ( P > 0.05). During exercise, the cardiovascular responses differed between sexes. Although fiber type composition was similar (type I: 47% ± 13% vs 56% ± 14%, P = 0.11), males had lower mitochondrial net oxidative capacity (61 ± 30 vs 89 ± 37, P = 0.049) and higher Complex II contribution to maximal respiration (CII; 59% ± 8% vs 48% ± 6%, P < 0.001), which correlated with the decline in MVIC ( r = -0.74, P < 0.001) and RT ( r = -0.60, P = 0.002).</p><p><strong>Conclusions: </strong>Females display greater resistance to PF during dynamic contractions, likely due to their superior mitochondrial efficiency and lower dependence on mitochondrial CII activity.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"376-389"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142133176","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":"Exercise and Heat Stress in Well-Healed Burn Survivors: Effects of Cooling Modalities on Thermal and Perceptual Responses.","authors":"Whitley C Atkins, Josh Foster, Zachary J McKenna, Caitlin P Jarrard, Joseph C Watso, Luke N Belval, Ollie Jay, Craig G Crandall","doi":"10.1249/MSS.0000000000003557","DOIUrl":"10.1249/MSS.0000000000003557","url":null,"abstract":"<p><strong>Purpose: </strong>Burn injuries that require grafting impair thermoregulation, which may dissuade individuals with such injuries from being physically active. We tested the hypothesis that cooling modalities attenuate core temperature elevations and perceptions of heat stress during physical activity in the heat among adults with well-healed burn injuries.</p><p><strong>Methods: </strong>Adults with no burn injuries (non-burned), 20%-40% body surface area burn injuries (moderate burn), and >40% body surface area burn injuries (large burn) performed 1 h of moderate-intensity exercise (2.5 ± 0.2 mph and 2% grade) on four different occasions in two environmental conditions (30°C and 39°C, 40% relative humidity). Within each environmental condition, we applied one of the following cooling modalities, random assigned, for each visit: no cooling (control), fan at 4 m·s -1 (fan), water spray every 5 min (water spray; scaled to burn area size), or a combination of water spray + fan.</p><p><strong>Results: </strong>In 30°C, perceptual strain index (PeSI) was reduced in the non-burned and moderate burn groups with water spray + fan, whereas PeSI was reduced with all cooling modalities in the large burn group. The cooling modalities did not affect core temperature responses. In the 39°C environment, water spray and water spray + fan attenuated the elevation in core temperature ( P ≤ 0.007) only in the large burn group. In the moderate burn group, PeSI was decreased with water spray + fan ( P = 0.017). In the large burn group, both water spray alone and water spray + fan ( P ≤ 0.041) lowered PeSI.</p><p><strong>Conclusions: </strong>For both environments across burn groups, the applied cooling modalities were generally more effective at reducing indices of perceptual strain relative to indices of thermal strain (e.g., core temperature).</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"365-375"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11729463/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142290796","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":"The Efficacy of Blood Flow Restriction Training to Improve Quadriceps Muscle Function after Anterior Cruciate Ligament Reconstruction.","authors":"Lauren N Erickson, Meredith K Owen, Kelsey R Casadonte, Tereza Janatova, Kathryn Lucas, Kylie Spencer, Benjamin D Brightwell, Megan C Graham, McKenzie S White, Nicholas T Thomas, Christine M Latham, Cale A Jacobs, Caitlin E Conley, Katherine L Thompson, Darren L Johnson, Peter A Hardy, Christopher S Fry, Brian Noehren","doi":"10.1249/MSS.0000000000003573","DOIUrl":"10.1249/MSS.0000000000003573","url":null,"abstract":"<p><strong>Background: </strong>Blood flow restriction training (BFRT) is a popular rehabilitation intervention after anterior cruciate ligament reconstruction (ACLR). However, there are a lack of clinical trials establishing the efficacy of using BFRT during rehabilitation to improve quadriceps muscle function.</p><p><strong>Purpose: </strong>The purpose of this study is to evaluate the efficacy of blood flow restriction training to improve quadriceps muscle strength, morphology, and physiology, and knee biomechanics in individuals after ACLR in a double-blind, randomized, placebo-controlled clinical trial (NCT03364647).</p><p><strong>Methods: </strong>Forty-eight athletes (20 females/28 males) were randomly assigned to low-load strength training with active BFRT or standard of care strength training with a sham unit. Treatment occurred for 1-month pre-surgery and 4 to 5 months post-surgery with both groups following the same standard rehabilitation protocol. Outcome variables were measured at baseline and 4 to 5 months post-surgery. Quadriceps muscle strength (isometric and isokinetic peak torque and rate of torque development) was measured on an isokinetic dynamometer. Quadriceps muscle morphology (physiological cross-sectional area, fibrosis) was determined using magnetic resonance imaging. Quadriceps muscle physiology (fiber type, fiber cross-sectional area, satellite cell abundance, collagen content, fibrogenic/adipogenic progenitor cells) was evaluated with muscle biopsies of the vastus lateralis. Knee extensor moment and knee flexion angle were measured via three-dimensional gait analysis. Change scores were calculated as: post-intervention - baseline. Two-sample t -tests were then used to assess between-group differences for each outcome variable.</p><p><strong>Results: </strong>No significant between-group differences were found for any outcome variable.</p><p><strong>Conclusions: </strong>The addition of BFRT to a rehabilitation program for athletes pre- and post-ACLR was no more effective than standard rehabilitation for improving quadriceps muscle function. Clinicians should consider the value of BFRT relative to the cost, time, and discomfort for patients in light of these results.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":"227-237"},"PeriodicalIF":4.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11729412/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142349734","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}