Medicine and Science in Sports and Exercise最新文献

{"title":"Relationship Between Changes in Physical Activity and Knee Health 18 Months after ACL Reconstruction.","authors":"Yvonne M Golightly, Michael D Rosenthal, Balasrinivasa Sajja, Chris Wichman, Melissa Manzer, Matt Tao, Elizabeth Wellsandt, David M Werner","doi":"10.1249/MSS.0000000000003787","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003787","url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to determine the relationship between changes in daily physical activity (PA) and knee health 18 months after anterior cruciate ligament reconstruction (ACLR). Knee health was defined using structural (quantitative magnetic resonance imaging [MRI]) and functional (patient-reported and objectively-measured knee function) constructs.</p><p><strong>Methods: </strong>Eighteen individuals (83.3% female, 19.7 ± 5.6 years old, BMI 23.9 ± 3.7 kg/m2) completed testing. Daily steps over one week and structural cartilage health, measured using a waist-worn accelerometer (Actigraph wGT3X-BT) and T2 relaxation time on MRI, respectively, were collected six and 18 months after ACLR. Eighteen months after ACLR patient-reported and objectively measured knee health were assessed using the International Knee Documentation Committee Subjective Knee Form (IKDC) and isometric quadriceps strength, respectively. A linear regression model was used to test the relationship between the change in PA from six to 18 months after ACLR and the percent change in T2 relaxation time of four cartilage regions (lateral and medial femoral and tibial cartilage) from six to 18 months after ACLR. A Fisher's Exact test assessed the relationship between change in PA (increase/decrease) between six and 18 months after ACLR and adequate/inadequate knee function using patient-reported (IKDC) and objectively measured (quadriceps strength) knee function 18 months after ACLR.</p><p><strong>Results: </strong>Participants averaged 7547.3 ± 2439.7 daily steps six months after ACLR and 7504.9 ± 3736.3 daily steps 18 months after ACLR. There was no association between change in PA and structural knee health (p = 0.069) or knee function (p = 0.638).</p><p><strong>Conclusions: </strong>Average daily steps did not change from six to 18 months after ACLR. PA from six to 18 months after ACLR was not associated with knee health outcomes at 18 months.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144310173","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":"24-Hour Low Energy Availability Induced by Diet or Exercise Exhibits Divergent Influences on Sleep and Recovery Indices among Female and Male Cyclists.","authors":"Ella S Smith, Megan Kuikman, Suzanna Rusell, Carissa L Gardiner, Shona L Halson, Trent Stellingwerff, Rachel Harris, Alannah K A McKay, Louise M Burke","doi":"10.1249/MSS.0000000000003783","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003783","url":null,"abstract":"<p><strong>Purpose: </strong>To examine the effects of 24-h manipulations in energy availability (EA), through altering energy intake (EI) or exercise energy expenditure (EEE), on sleep characteristics and nocturnal heart rate variability (HRV).</p><p><strong>Methods: </strong>20 endurance athletes (10 females, 10 males) undertook five 24-h periods of EA manipulation, separated by 8 days, in a randomized Latin Square design. Following 24-h of standardized high EA (45 kcal·kg-1FFM·day-1), athletes then followed a diet providing low EA (15 kcal·kg-1FFM·day-1) either with/without exercise (LEAEX/REST), high EA (45 kcal·kg-1FFM·day-1) with/without exercise (HEAEX/REST) and excess EA (75 kcal·kg-1FFM·day-1) without exercise (GEA). Sleep and overnight HRV were assessed using Somfit and Oura ring devices, respectively, pre- and post-EA manipulation.</p><p><strong>Results: </strong>Total sleep duration was extended by 53-61 min following LEAEX versus non-exercise conditions: GEA (p = 0.002), HEAREST (p = 0.003), and LEAREST (p = 0.020). Time in bed was also increased during LEAEX compared to GEA (p = 0.006) and HEAREST (p = 0.023), but without alterations to sleep efficiency between conditions (p = 0.613). Sleep onset latency increased by 8 min following LEAREST compared to GEA (p = 0.012), while there were no other alterations to objective/subjective sleep characteristics between conditions (all p > 0.05). There was no difference in overnight HRV following the 24-h EA manipulation (p > 0.05). However, mean overnight HR was lower following LEAREST and HEAREST (-4 ± 3 and -2 ± 3 b·min-1), compared to LEAEX (+1 ± 3 b·min-1), HEAEX (0 ± 3 b·min-1) and GEA (0 ± 3 b·min-1, all p < 0.01). There was no difference between sexes in the response to EA manipulation across all variables.</p><p><strong>Conclusions: </strong>24-h of exercise-induced LEA extended total sleep time, while diet-induced LEA reduced mean overnight HR. The responses to EA manipulations did not differ between sexes.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144310169","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":"Assessing the Validity of Wearable Inertial Sensors in Evaluating Joint Kinetics and Hamstring Musculotendon Mechanics at Various Running Speeds.","authors":"Yi-Chung Lin, Kara Price, Declan Carmichael, Nirav Maniar, Jack Hickey, Ryan Timmins, Bryan Heiderscheit, Silvia Blemker, David Opar","doi":"10.1249/MSS.0000000000003786","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003786","url":null,"abstract":"<p><strong>Purpose: </strong>Integrating musculoskeletal (MSK) modelling with inertial measurement units (IMUs) offers a promising approach for analysing joint and muscle function during locomotion. This study examined the validity of combining IMUs, MSK modelling, and inverse dynamics to estimate lower-limb joint moments and hamstring musculotendon (MT) mechanics during treadmill running at varying speeds.</p><p><strong>Methods: </strong>Eighteen healthy young adults ran on a treadmill at 70% (5.21 ± 0.62 m/s), 80% (5.96 ± 0.71 m/s), 85% (6.33 ± 0.76 m/s), 90% (6.70 ± 0.80 m/s), 95% (7.07 ± 0.84 m/s), and 100% (7.44 ± 0.89 m/s) of their maximal sprinting speed. Kinematic data were simultaneously collected using both an optical motion capture (OMC) system (Vicon) and an IMU system (Xsens), while electromyographic (EMG) data recorded hamstring activity. MSK modelling was applied to both kinematic measurements to calculate lower-limb joint moments and hamstring MT mechanics, with estimated muscle activations validated against the EMG data.</p><p><strong>Results: </strong>IMU-based estimations closely matched OMC-based calculations, with coefficient of multiple correlations (CMC) exceeding 0.85 for hip and knee joint moments during swing and 0.95 for hamstring MT kinematics across full stride cycles at all speeds. MT force estimations varied among hamstring muscles, with semimembranosus showing the highest agreement (0.96 < CMC < 0.98) across all speeds. Linear mixed models showed for each 1 m/s speed increase, root mean square errors between the two systems increased by less than 0.25 N/m for joint moments and 0.05 BW for hamstring MT forces.</p><p><strong>Conclusions: </strong>IMU-MSK integration is a valid alternative to OMC for estimating sagittal-plane joint moments and hamstring MT mechanics during treadmill running, though differences in peak hip moment during terminal swing warrant caution in field-based applications.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144310170","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":"Wearing a Guardian Cap Does Not Mitigate On-field Head Impact Severity.","authors":"Robert C Lynall, Aaron M Sinnott, Charles Van Dyke, Kim Love, Julianne D Schmidt, Jason P Mihalik","doi":"10.1249/MSS.0000000000003790","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003790","url":null,"abstract":"<p><strong>Purpose: </strong>Guardian Cap usage is growing amongst youth, college, and professional football players. Little on-field data exist describing Guardian Cap effectiveness, with combined published evidence based on less than 1,000 Guardian Cap impacts. Our objective was to compare on-field head impact biomechanics (magnitude, location, frequency) between college football athletes wearing a Guardian Cap and teammates not wearing a Guardian Cap during practices and games throughout a season.</p><p><strong>Methods: </strong>Fifty-four participants from two institutions were enrolled. Eleven (20.4%) wore a Guardian Cap for all contact practices, 43 (79.6%) did not wear a Guardian Cap for one season. Instrumented mouthguards recorded on-field head impact kinematics. Impact magnitude (linear mixed effects models), frequency, and location (generalized linear mixed models) were analyzed.</p><p><strong>Results: </strong>A total of 7,509 impacts were recorded, including 1,379 (18.4%) impacts when the Guardian Cap was worn. There were no significant effects of Guardian Cap use for any impact magnitude outcome (p ≥ 0.127) or impact frequency (p = 0.508). The odds of a facemask impact relative to other locations were 36.2% lower among those wearing the Guardian Cap relative to non-wearers (p = 0.014). The odds of a rear impact relative to other locations were 151.6% greater among those wearing the Guardian Cap relative to non-wearers (p = 0.001).</p><p><strong>Conclusions: </strong>The Guardian Cap had no on-field effect on head impact magnitude or frequency, but impact location patterns presented between wearers and non-wearers, suggesting Guardian Cap usage could influence how players use their head during collisions. Our findings partially align with other published data. The effect of Guardian Cap use on other factors we did not explore (e.g., injury epidemiology, clinical injury management) warrants consideration in the context of the data we present.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144310187","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":"Recovery of Fatigue, Cardiorespiratory Fitness, and Neuromuscular Function in Covid-19 ICU Patients: A 6-Month Follow-Up Study.","authors":"Djahid Kennouche, Clément Foschia, Callum G Brownstein, Julien Gondin, Thomas Lapole, Diana Rimaud, Nicolas Royer, Guillaume Thiery, Vincent Gauthier, Pascal Giraux, Lydia Oujamaa, Marine Sorg, Samuel Vergès, Stéphane Doutreleau, Mathieu Marillier, Mélanie Prudent, Laurent Bitker, Léonard Féasson, Laurent Gergelé, Emeric Stauffer, Céline Guichon, Jérôme Morel, Guillaume Y Millet","doi":"10.1249/MSS.0000000000003789","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003789","url":null,"abstract":"<p><strong>Purpose: </strong>Although most patients recover well from Covid-19 infection, this may not be the case of those who experienced severe dysfunction after being admitted to intensive care unit (ICU). This study aimed to assess the recovery of patients who experienced severe multiple dysfunctions after being admitted to intensive care unit (ICU) for Covid-19 infection.</p><p><strong>Methods: </strong>Forty-seven patients hospitalized and mechanically ventilated in ICU for SARS-CoV-2 infection underwent evaluations at 4-8 weeks (T1) and 6 months (T2) post ICU discharge. Evaluations included questionnaires, lung function tests, incremental cardiopulmonary exercise testing, and neuromuscular function tests.</p><p><strong>Results: </strong>From T1 to T2, the percentage of patients classified as fatigued decreased from 56% to 21% whereas forced vital capacity and the forced expiratory volume in one second increased by 13% and 8% (p < 0.05) to reach 93% and 95% of predicted values at T2, respectively. Peak work rate also increased from 97 to 135 W (+35 ± 32%, p < 0.001). Likewise, V̇O2peak increased from 18.3 to 21.6 ml/min/kg (+18 ± 27%, p < 0.001) to reach 72% of predicted values. Maximal strength and the number of contractions during the fatigability test increased between T1 and T2 by 41% and 39%, respectively (both p < 0.001).</p><p><strong>Conclusions: </strong>Six months of recovery improved patients' physical function and reduced fatigue.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144310172","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":"Exogenous Ketosis during Early Acclimatization at High Altitude: Ventilatory, Cardiovascular and Muscular Responses to Maximal Exercise.","authors":"Domen Tominec, Myrthe Stalmans, Benjamin J Narang, Grégoire P Millet, Chiel Poffé, Tadej Debevec","doi":"10.1249/MSS.0000000000003791","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003791","url":null,"abstract":"<p><strong>Background: </strong>Exogenous ketosis, induced via ketone monoester (KE) ingestion, can attenuate blood desaturation and muscle deoxygenation during hypoxic exercise. However, its effect(s) on exercise capacity and underlying integrated physiological responses to incremental exercise to exhaustion during early acclimatization at terrestrial high altitude remain unexplored.</p><p><strong>Methods: </strong>Healthy active adults were randomised to an intermittent exogenous ketosis (IEK; n = 16) or placebo (PLA, n = 17) group, before performing two incremental cycling tests to volitional exhaustion. The first was conducted at sea level (295 m) without prior supplementation. The second was conducted at high altitude (3375 m) following ~69 hours of acclimatization, during which participants intermittently ingested KE (IEK) or placebo (PLA). During exercise, gas exchange, cardiac output, and both blood and muscle oxygenation were recorded continuously using a metabolic cart, transthoracic impedance, earlobe oximetry and near-infrared spectroscopy, respectively.</p><p><strong>Results: </strong>Pre-exercise blood ketone concentrations were higher in IEK than PLA (~2.1 mM vs. ~0.3 mM, P < 0.001). However, both experimental groups exhibited comparable (P = 0.525-0.644) high altitude-induced reductions in peak power output (P < 0.001), as well as in blood (P < 0.001) and muscle oxygenation (P < 0.001) during maximal exercise and submaximal power levels. Furthermore, high altitude significantly increased resting and/or exercising ventilation (P < 0.001) and cardiac output (P < 0.001), yet irrespective of the KE vs. placebo ingestion (P = 0.529-0.828).</p><p><strong>Conclusions: </strong>These findings indicate that intermittent exogenous ketosis during early acclimatization does not mitigate altitude- and exercise-induced reductions in blood and muscle oxygenation. Moreover, it does not importantly modulate ventilatory and cardiac output responses, and therefore does not seem to confer ergogenic advantage during subacute high altitude exposures.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144310171","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 Effects of Ingesting a Single Bolus of Hydrolyzed Collagen versus Free Amino Acids on Muscle Connective Protein Synthesis Rates.","authors":"Thorben Aussieker, Jeremias Kaiser, Floris K Hendriks, Tom A H Janssen, Joan M Senden, Janneau M X van Kranenburg, Joy P B Goessens, Antoine Zorenc, Esther Kornips, Tjinta Brinkhuizen, Keith Baar, Tim Snijders, Andrew M Holwerda, Luc J C van Loon","doi":"10.1249/MSS.0000000000003788","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003788","url":null,"abstract":"<p><strong>Purpose: </strong>To assess the impact of ingesting a single bolus of hydrolyzed collagen or free amino acids on myofibrillar and muscle connective protein synthesis rates.</p><p><strong>Methods: </strong>In a randomized, double-blind, parallel design, 45 young male (n = 21) and female (n = 24) adults (age: 23 ± 3 y; BMI: 22.3 ± 2.2 kg/m2) received intravenous infusions with L-[ring-13C6]-phenylalanine. Following unilateral resistance exercise, participants ingested either 30 g hydrolyzed collagen (COLL, n = 15), 30 g free amino acids reflecting the collagen amino acid profile (AA, n = 15), or a non-caloric placebo (PLA, n = 15). Blood and muscle tissue samples were collected over 6 h to assess myofibrillar and muscle connective protein synthesis rates and associated signaling responses.</p><p><strong>Results: </strong>Both collagen and free amino acid ingestion substantially increased circulating plasma amino acids concentrations and effected collagen turnover proteins. Collagen and free amino acid ingestion did not significantly increase myofibrillar protein synthesis rates in the rested (0.039 ± 0.011, 0.037 ± 0.010, and 0.036 ± 0.015%·h-1 in PLA, COLL and AA, respectively) or the exercised (0.049 ± 0.010, 0.048 ± 0.011, and 0.045 ± 0.013%·h-1) leg (P > 0.05). Similarly, both collagen and free amino acid ingestion did not significantly increase muscle connective protein synthesis rates in the rested (0.065 ± 0.014, 0.063 ± 0.017, and 0.061 ± 0.025%·h-1 in PLA, COLL and AA, respectively) or the exercised (0.098 ± 0.023, 0.092 ± 0.028, and 0.085 ± 0.024%·h-1) leg (P > 0.05).</p><p><strong>Conclusions: </strong>Ingestion of a single bolus of collagen hydrolysate or free amino acids substantially increases circulating amino acids concentrations, particularly glycine, but does not further increase myofibrillar or muscle connective protein synthesis rates at rest or during recovery from exercise in healthy, recreationally active young men and women.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144310174","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":"Changes in Body Composition in Relation to Metabolic Syndrome: A Compositional Analysis in Adults with Overweight and Obesity.","authors":"Erin Miller, Ian Janssen, Robert Ross","doi":"10.1249/MSS.0000000000003778","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003778","url":null,"abstract":"<p><strong>Background/purpose: </strong>Current knowledge of the association between body composition and health outcomes is based on traditional regression techniques, where the components of body composition are treated as non-compositional independent variables. Mounting evidence suggests that body tissues are biologically co-dependent and therefore, require a statistical technique that considers this. This study used a compositional data analysis framework to explore the longitudinal association between body composition and a continuous metabolic syndrome score.</p><p><strong>Methods: </strong>Participants included 288 physically inactive adults (age: 56 ± 12 years [mean ± SD]; 56% female) with overweight or obesity (BMI: 31.3 ± 3.5 kg/m2) who participated in randomized controlled trials that determined the effects of exercise on adipose tissue (visceral, abdominal subcutaneous, peripheral subcutaneous, other adipose tissues) and lean tissues (skeletal muscle, other lean tissues) assessed by whole-body magnetic resonance imaging.</p><p><strong>Results: </strong>Visceral adipose tissue, relative to the mass of the remaining tissues, was significantly associated with the metabolic syndrome score pre- and post-intervention (P < 0.05). The slopes and intercepts of the pre- and post-intervention regression lines between relative visceral adipose tissue mass and metabolic syndrome did not differ (P > 0.2). For a given weight loss, the greater the relative reduction in visceral adipose tissue, the larger the decrease in the predicted metabolic syndrome score.</p><p><strong>Conclusions: </strong>This novel compositional data analysis reinforces that visceral adipose tissue is an important marker of cardiometabolic risk and should be a primary target for therapeutic strategies in individuals with overweight or obesity.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144275245","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":"Heavy Intensity Priming Exercise Attenuates the Rate of Quadriceps Muscle Fatigue and Improves Time-to-Task Failure during Severe Intensity Cycling.","authors":"Keenan B MacDougall, Saied J Aboodarda, Austin B Wickenberg, Brian R MacIntosh","doi":"10.1249/MSS.0000000000003785","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003785","url":null,"abstract":"<p><strong>Background: </strong>Prior high-intensity exercise (priming) has been shown to accelerate the V̇O2 kinetics, as well as improve exercise tolerance during subsequent high-intensity exercise, yet the mechanisms underpinning the performance changes are unclear. In theory, a reduced reliance on non-oxidative energy input afforded by the faster V̇O2 response may improve subsequent performance by delaying muscle fatigue, however, this effect has yet to be conclusively shown.</p><p><strong>Purpose: </strong>Our purpose was to explore the impact of priming exercise on the energetic response, exercise tolerance, and the kinetics of muscle fatigue during severe intensity cycling exercise.</p><p><strong>Methods: </strong>Fourteen participants completed constant power cycling trials in the severe domain, preceded by either a bout of heavy intensity, or an equivalent duration cycling at 20 W. Muscle fatigue was assessed in real-time via femoral nerve stimulation while pedaling, and energetic contributions were assessed via V̇O2 and changes in blood lactate concentration. Quadriceps oxygenation and surface electromyography (EMG) were also measured.</p><p><strong>Results: </strong>Priming improved time-to-task failure (450 ± 74 s) compared to control (391 ± 92 s) (P = 0.008). Relative oxidative contributions increased following priming (P = 0.001), while the non-oxidative glycolytic contribution was reduced (P < 0.0001), and this was accompanied by a reduction in the rate of quadriceps twitch force decline (P = 0.041). Vastus lateralis EMG root mean square amplitude and M-wave amplitude increased across the trial similarly in both conditions, but priming resulted in a relative \"downshift\" in both measures (P ≤ 0.027).</p><p><strong>Conclusions: </strong>Priming exercise resulted in an improvement in exercise tolerance, attenuation in muscle fatigue, and reduction in EMG and M-wave amplitude. We speculate that these effects may arise in part from the interaction between a reduction in metabolite accumulation and altered sarcolemmal excitability.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144275246","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":"Supplemental Oxygen during Exercise Training in Chronic Obstructive Pulmonary Disease.","authors":"Sara Faggian, Francesca Battista, Marco Vecchiato, Richard Casaburi, Margareta Emtner, Nicola Borasio, Michael Studnicka, Andrea Ermolao, Josef Niebauer, Daniel Neunhaeuserer","doi":"10.1249/MSS.0000000000003782","DOIUrl":"https://doi.org/10.1249/MSS.0000000000003782","url":null,"abstract":"<p><strong>Introduction: </strong>chronic obstructive pulmonary disease is a leading cause of mortality worldwide and a debilitating condition that leads to years of poor quality of life. Physical exercise training is an evidence-based treatment well documented to improve these outcomes as well as morbidity, dyspnoea and functional capacity. Moreover, scientific evidence from pooled analyses currently provides equivocal evidence for oxygen supplementation to overcome ventilatory limitations during exercise training, with several studies reporting no additional benefits when compared with training in room air. However, when individually analyzing the underlying studies from an exercise physiology perspective, some critical aspects arise.</p><p><strong>Purpose: </strong>this review aims to systematically investigate and highlight the impact of patients' characteristics, exercise induced desaturation, oxygen delivery, influence of breathing conditions during exercise testing and prescription, outcome-training specificity, exercise intensity and modality, as well as progressive work rate adjustments over the course of the training intervention.</p><p><strong>Methods: </strong>the research methodology is based on a literature search of the available evidence starting from the published systematic reviews and meta-analyses, and integrating available original articles from the respective reference lists.</p><p><strong>Results: </strong>although evidence is still limited, supplemental oxygen might be specifically useful for certain responding patients and in specific clinical conditions, when high-intensity training is performed, thereby increasing exercise tolerance in order to improve training adaptations and thus peak exercise capacity/endurance.</p><p><strong>Conclusions: </strong>future well-designed clinical trials may better implement these methodological training principles in their study design and investigate if advantages from normoxic and hyperoxic exercise training can be weighed, showing how, when and in which patients supplemental oxygen could be best used in order to reach predefined training goals in pulmonary rehabilitation.</p>","PeriodicalId":18426,"journal":{"name":"Medicine and Science in Sports and Exercise","volume":" ","pages":""},"PeriodicalIF":4.1,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144275248","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}